Obstetrics and Gynecology

1046 questions

Question 841Question →

Appropriate maternal weight gain during pregnancy is an essential component of routine prenatal care to optimize maternal and fetal outcomes. Based on the Institute of Medicine (IOM) guidelines for singleton pregnancies, match each patient's pre-pregnancy Body Mass Index (BMI) presentation with the most appropriate recommended total gestational weight gain range.

Click a left item, then click its matching right item

Items

A primigravid patient with a pre-pregnancy BMI of 17.5 kg/m217.5 \text{ kg/m}^2
A multigravid patient with a pre-pregnancy BMI of 22.0 kg/m222.0 \text{ kg/m}^2
A primigravid patient with a pre-pregnancy BMI of 27.5 kg/m227.5 \text{ kg/m}^2
A multigravid patient with a pre-pregnancy BMI of 33.4 kg/m233.4 \text{ kg/m}^2

Matches

Show answer & explanation

Answer

The correct matches align weight gain targets inversely with pre-pregnancy BMI: the underweight patient (BMI 17.5 kg/m217.5 \text{ kg/m}^2) matches to 28−40 lbs28-40 \text{ lbs}, the normal weight patient (BMI 22.0 kg/m222.0 \text{ kg/m}^2) matches to 25−35 lbs25-35 \text{ lbs}, the overweight patient (BMI 27.5 kg/m227.5 \text{ kg/m}^2) matches to 15−25 lbs15-25 \text{ lbs}, and the obese patient (BMI 33.4 kg/m233.4 \text{ kg/m}^2) matches to 11−20 lbs11-20 \text{ lbs}.
Gestational weight gain recommendations are inversely proportional to the patient's pre-pregnancy BMI to optimize outcomes for both the mother and the fetus. Underweight patients (BMI <18.5 kg/m2< 18.5 \text{ kg/m}^2) should gain 28−40 lbs28-40 \text{ lbs}; normal weight patients (BMI 18.5−24.9 kg/m218.5-24.9 \text{ kg/m}^2) should gain 25−35 lbs25-35 \text{ lbs}; overweight patients (BMI 25.0−29.9 kg/m225.0-29.9 \text{ kg/m}^2) should gain 15−25 lbs15-25 \text{ lbs}; and obese patients (BMI ≥30.0 kg/m2\geq 30.0 \text{ kg/m}^2) should gain 11−20 lbs11-20 \text{ lbs}. Adhering to these guidelines minimizes the risks of small-for-gestational-age infants in undernourished mothers and mitigates complications like gestational diabetes, gestational hypertension, and macrosomia in overweight or obese mothers.

Step-by-Step Solution

1
Categorize each patient's baseline Body Mass Index (BMI) into standard classifications.
A BMI of 17.5 kg/m217.5 \text{ kg/m}^2 is classified as underweight, 22.0 kg/m222.0 \text{ kg/m}^2 as normal weight, 27.5 kg/m227.5 \text{ kg/m}^2 as overweight, and 33.4 kg/m233.4 \text{ kg/m}^2 as obese.
Gestational weight gain recommendations are strictly stratified according to a patient's pre-pregnancy BMI category.
2
Determine the Institute of Medicine (IOM) weight gain target for each identified category in a singleton pregnancy.
The recommended ranges are: Underweight requires 2828 to 40 lbs40 \text{ lbs}, normal weight requires 2525 to 35 lbs35 \text{ lbs}, overweight requires 1515 to 25 lbs25 \text{ lbs}, and obese requires 1111 to 20 lbs20 \text{ lbs}.
These specific weight trajectories minimize the risk of perinatal complications, balancing fetal nutritional needs against the hazards of excessive maternal weight gain.
3
Align the specific patient clinical scenarios with their appropriate recommended weight gain ranges.
The patient with BMI 17.5 kg/m217.5 \text{ kg/m}^2 is mapped to 28−40 lbs28-40 \text{ lbs}. The patient with BMI 22.0 kg/m222.0 \text{ kg/m}^2 is mapped to 25−35 lbs25-35 \text{ lbs}. The patient with BMI 27.5 kg/m227.5 \text{ kg/m}^2 is mapped to 15−25 lbs15-25 \text{ lbs}. The patient with BMI 33.4 kg/m233.4 \text{ kg/m}^2 is mapped to 11−20 lbs11-20 \text{ lbs}.
This establishes the definitive mapping for evidence-based prenatal counseling.

Key Concept

Institute of Medicine (IOM) guidelines for gestational weight gain based on pre-pregnancy BMI
Question 842Question →

During a routine health maintenance visit, a thirty-four-year-old patient reports that she has not menstruated for the past nine months. Her menarche occurred at age 1212, and previously she experienced predictable 2828-day cycles. Over the last several months, she has been struggling with unexpected mood fluctuations, poor sleep, and sudden, intense episodes of upper body warmth accompanied by sweating. She is nulligravid, has no history of chronic medical conditions, and does not take any medications. Vital signs are within normal limits, with a BMI of 24 kg/m224 \text{ kg/m}^2. On physical examination, her secondary sexual characteristics are appropriately developed. Pelvic examination reveals a pale vaginal mucosa with diminished rugae, but no adnexal masses are palpated. The thyroid gland is normal to palpation, and there is no evidence of galactorrhea or hirsutism. Arrange the following clinical interventions in the correct chronological sequence to appropriately evaluate and manage this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: first, rule out pregnancy with a beta-hCG test; second, obtain initial hormone levels (FSH, TSH, prolactin); third, confirm primary ovarian insufficiency with a repeat FSH test 4 weeks later; fourth, investigate the underlying etiology with genetic testing; and fifth, initiate hormone replacement therapy to prevent long-term complications.
The correct sequence follows the standard diagnostic algorithm for secondary amenorrhea presenting with signs of estrogen deficiency. Pregnancy is excluded first, followed by initial hormone screening. Because a single elevated FSH can be a transient anomaly, it must be repeated in 4 weeks to officially diagnose primary ovarian insufficiency (POI). Once POI is confirmed, genetic etiology is investigated, and finally, hormone replacement therapy is initiated.

Step-by-Step Solution

1
Obtain a beta-hCG test.
Pregnancy is definitively ruled out.
Pregnancy is the most common cause of secondary amenorrhea and must be excluded before any further endocrine workup is performed.
2
Measure initial serum FSH, TSH, and prolactin levels.
FSH is found to be elevated in the menopausal range, while TSH and prolactin are normal.
These tests evaluate the most common non-pregnancy causes of amenorrhea. An elevated FSH alongside estrogen deficiency symptoms strongly suggests primary ovarian insufficiency (POI).
3
Repeat the serum FSH measurement after at least 4 weeks.
The second FSH level remains elevated, confirming the diagnosis of POI.
Gonadotropin levels can fluctuate naturally. The biochemical diagnosis of POI requires two elevated FSH measurements separated by at least 1 month.
4
Perform karyotype analysis and FMR1 gene premutation screening.
The underlying genetic or autoimmune etiology of the patient's POI is evaluated.
In women diagnosed with POI before age 40, identifying a specific etiology (such as Turner mosaicism or Fragile X premutation) is crucial for genetic counseling and identifying associated health risks.
5
Initiate systemic hormone replacement therapy (HRT) containing estrogen and a progestin.
The patient's vasomotor symptoms improve, and she is protected against premature bone loss.
Long-term estrogen deficiency at a young age significantly increases the risk of severe osteoporosis and cardiovascular disease. HRT is indicated until the natural age of menopause.

Key Concept

Step-wise evaluation and management of primary ovarian insufficiency (POI) presenting as secondary amenorrhea.
Estimated Time:1m 30s
Question 843Question →

A 28-year-old primigravida at 4141 weeks gestation is admitted to the labor and delivery unit for induction of labor. Following cervical ripening, a continuous intravenous oxytocin infusion is started. Twelve hours later, the patient reports intense and continuous abdominal pain. Her temperature is 37.2∘C37.2^\circ\text{C} (99.0∘F99.0^\circ\text{F}), blood pressure is 122/78 mm Hg122/78\text{ mm Hg}, and pulse is 92/min92/\text{min}. A sterile vaginal examination reveals the cervix is 6 cm6\text{ cm} dilated and 90%90\% effaced, with the fetal vertex at 00 station. The external tocodynamometer records 77 uterine contractions in a 1010-minute period, averaged over the last 3030 minutes. The continuous fetal heart rate tracing demonstrates a baseline of 145/min145/\text{min}, moderate variability, and symmetric decreases in the heart rate that begin after the peak of each contraction and slowly return to baseline after the contraction ends. Repositioning the patient to the left lateral decubitus position and providing a rapid intravenous fluid bolus do not resolve the fetal heart rate findings. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Discontinue the oxytocin infusion

Answer

The correct answer is to discontinue the oxytocin infusion to resolve the uterine tachysystole and improve uteroplacental blood flow.
This patient is experiencing uterine tachysystole, defined as >5>5 contractions in a 1010-minute period averaged over 3030 minutes. The excessively frequent contractions prevent adequate relaxation of the myometrium, impeding the restoration of uteroplacental blood flow between contractions. This uteroplacental insufficiency is clinically manifesting as recurrent late decelerations on the fetal heart rate monitor. The initial management for tachysystole with a Category II fetal heart rate tracing includes supportive measures such as lateral maternal repositioning and intravenous fluid boluses. Because this patient's tracing has not improved with these initial interventions and she is currently receiving an oxytocin infusion, the most direct, required next step is to immediately discontinue the oxytocin. This will reduce contraction frequency and allow uteroplacental perfusion to recover.

Step-by-Step Solution

1
Analyze the uterine activity from the tocodynamometer.
The patient is having 7 contractions per 10 minutes.
Uterine tachysystole is defined as more than 5 contractions in a 10-minute window, which can compromise blood flow to the fetus.
2
Interpret the fetal heart rate (FHR) tracing.
The FHR shows a normal baseline and moderate variability, but recurrent late decelerations are present.
Late decelerations are a sign of uteroplacental insufficiency, which in this case is secondary to the excessive uterine contractions.
3
Determine the appropriate order of intrauterine resuscitation interventions.
Since maternal repositioning and fluid bolus failed, the oxytocin must be stopped.
When tachysystole is iatrogenic, discontinuing the uterotonic agent is the most direct and necessary next step before proceeding to tocolytics or surgery.

Key Concept

Management of oxytocin-induced uterine tachysystole with abnormal fetal heart rate tracing requires immediate discontinuation of the oxytocin infusion.
Question 844Question →

A 39-year-old woman, G0, comes to the clinic due to a three-week history of continuous, heavy vaginal bleeding. She states that she has soaked through a thick maxi pad every 3 hours for the past week. The patient has a history of irregular menstrual cycles, with periods occurring unpredictably every 2 to 6 months since menarche. Medical history is notable for hypertension, for which she takes amlodipine. She does not use tobacco or alcohol. Her blood pressure is 138/88 mm Hg138/88 \text{ mm Hg}, pulse is 88/min88/\text{min}, and BMI is 38 kg/m238 \text{ kg/m}^2. Physical examination reveals dark, velvety patches of skin on the posterior neck and axillae. Pelvic examination shows active bleeding from the cervical os; the uterus is normal in size and non-tender. A urine pregnancy test is negative. Complete blood count shows a hemoglobin of 10.4 g/dL10.4 \text{ g/dL} and a platelet count of 250,000/mm3250,000/\text{mm}^3. Thyroid-stimulating hormone level is within normal limits. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Endometrial biopsy

Answer

Endometrial biopsy
Endometrial biopsy is the gold standard initial test for abnormal uterine bleeding in premenopausal women who possess risk factors for endometrial hyperplasia or cancer. This patient's history of oligomenorrhea since menarche, physical signs of insulin resistance (acanthosis nigricans), and obesity strongly suggest polycystic ovary syndrome (PCOS). In PCOS, chronic anovulation leads to continuous, unopposed estrogen stimulation of the endometrium without the protective shedding induced by progesterone. This significantly increases the risk of endometrial hyperplasia and carcinoma. Clinical guidelines recommend endometrial biopsy for women ≥45\ge 45 years with abnormal bleeding, AND for women <45< 45 years if they have a history of unopposed estrogen exposure, failed medical management, or persistent abnormal bleeding.

Step-by-Step Solution

1
Identify the patient's primary presentation.
A 39-year-old premenopausal woman presenting with acute on chronic abnormal uterine bleeding.
Establishing the clinical problem directs the diagnostic algorithm.
2
Evaluate the patient's risk factors for endometrial pathology.
The patient has a history of chronic anovulation (irregular menses since menarche) and obesity (BMI 38 kg/m238 \text{ kg/m}^2), which are significant risk factors for unopposed estrogen exposure.
Unopposed estrogen increases the risk for endometrial hyperplasia and carcinoma.
3
Determine the most appropriate diagnostic test based on age and risk factors.
Guidelines recommend endometrial biopsy for women under 45 with abnormal uterine bleeding if they have risk factors for endometrial cancer.
Tissue diagnosis is required to rule out malignancy before initiating medical management.

Key Concept

Premenopausal women with abnormal uterine bleeding and risk factors for unopposed estrogen exposure (e.g., obesity, chronic anovulation) require an endometrial biopsy to rule out endometrial hyperplasia or cancer.
Question 845Question →

A 3131-year-old woman, gravida 22, para 11, presents to the clinic for her initial prenatal visit at 1111 weeks gestation. She reports mild nausea and breast tenderness but otherwise feels well. She has no significant past medical history and takes only a daily prenatal vitamin. Her blood pressure is 112/70 mm Hg112/70\text{ mm Hg} and pulse is 84/min84/\text{min}. Physical examination reveals a normal-sized thyroid gland without palpable nodules or tenderness. Pelvic examination is consistent with an 1111-week gestation. Routine initial prenatal laboratory studies are obtained, and the results of a reflexively drawn thyroid panel are as follows:

Thyroid-stimulating hormone (TSH): 0.15 μU/mL0.15\ \mu\text{U/mL} (Reference: 0.4–4.0 μU/mL0.4\text{--}4.0\ \mu\text{U/mL})
Total thyroxine (T4): 14.8 μg/dL14.8\ \mu\text{g/dL} (Reference: 5.0–12.0 μg/dL5.0\text{--}12.0\ \mu\text{g/dL})
Free thyroxine (T4): 1.6 ng/dL1.6\text{ ng/dL} (Reference: 0.8–1.8 ng/dL0.8\text{--}1.8\text{ ng/dL})

Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Reassurance and routine prenatal care

Answer

Reassurance and routine prenatal care
The correct answer accurately identifies that a low TSH and high total T4, in the presence of a normal free T4, are expected physiologic findings in the first trimester. This is driven by hCG acting on the TSH receptor and estrogen increasing thyroxine-binding globulin levels. Because this is normal physiology, reassurance is the only necessary step.

Step-by-Step Solution

1
Analyze the laboratory results in the context of the patient's gestational age.
The patient has a suppressed TSH, elevated total T4, and normal free T4 at 11 weeks gestation.
Identifying the specific pattern of thyroid function tests is essential to differentiate normal physiologic adaptations from true endocrine pathology.
2
Recall the physiologic changes of pregnancy regarding the thyroid gland.
Elevated estrogen increases thyroxine-binding globulin (TBG), leading to higher total T4. Concurrently, human chorionic gonadotropin (hCG) acts on the TSH receptor, mildly stimulating the thyroid and suppressing endogenous TSH.
Understanding the mechanism of hCG and estrogen on the thyroid axis explains the observed, non-pathological laboratory pattern.
3
Determine the appropriate management strategy based on the findings.
Because this is a normal physiologic state with a preserved normal free T4, no medical intervention is needed. Reassurance is the correct approach.
Intervening in normal physiologic adaptations can cause iatrogenic harm to both the mother and the fetus.

Key Concept

Normal physiologic changes in thyroid function during early pregnancy, characterized by increased total T4 (due to elevated TBG) and decreased TSH (due to hCG-mediated TSH receptor stimulation).
Estimated Time:1m 0s
Question 846Question →

A 24-year-old primigravida presents to the clinic at 10 weeks gestation reporting severe nausea, vomiting, and dark red vaginal spotting for the past two days. Her blood pressure is 142/90 mmHg, and her heart rate is 105/min. Physical examination reveals a uterus that is palpably enlarged to the level of the umbilicus, which is consistent with a 20-week gestation. A bedside urine pregnancy test is positive. She has no significant past medical history.

Arrange the following steps in the most appropriate chronological sequence for the diagnosis, definitive management, and standard follow-up of this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is: Transvaginal ultrasonography -> Suction curettage -> Weekly beta-hCG monitoring -> Monthly beta-hCG monitoring -> Clearance to attempt a new pregnancy.
The appropriate chronological management of a suspected complete hydatidiform mole begins with diagnostic confirmation via transvaginal ultrasonography. Once confirmed, the immediate primary treatment is surgical evacuation of the uterus via suction curettage. Because complete moles carry a 15-20% risk of malignant transformation into gestational trophoblastic neoplasia (GTN), strict post-evacuation surveillance is mandatory. Surveillance begins with weekly quantitative beta-hCG levels until they become completely undetectable for three consecutive weeks. After this milestone is achieved, surveillance is transitioned to monthly testing for six additional months. Throughout this entire process, the patient is required to use reliable contraception. Only after the six-month surveillance period is entirely complete can she safely discontinue contraception and attempt a new pregnancy.

Step-by-Step Solution

1
Diagnose the underlying condition based on the clinical presentation.
The patient has a suspected complete hydatidiform mole.
She presents with classic signs of a molar pregnancy, including significant size-dates discrepancy (uterus at umbilicus is typically ~20 weeks, but she is only at 10 weeks), severe hyperemesis gravidarum, and early-onset hypertension (suggestive of preeclampsia before 20 weeks).
2
Determine the initial diagnostic imaging test.
Transvaginal ultrasonography.
Ultrasound is the imaging modality of choice to visualize the uterine contents, confirm the absence of a normal fetus, and identify the characteristic vesicular swelling of a molar pregnancy.
3
Select the definitive primary treatment.
Suction curettage.
The molar pregnancy must be surgically evacuated promptly to resolve symptoms, treat the early onset preeclampsia, and mitigate the risk of malignant transformation.
4
Establish the initial postoperative surveillance plan.
Weekly beta-hCG monitoring.
Weekly monitoring is required immediately post-evacuation until the beta-hCG levels drop to zero for three consecutive weeks to verify initial clearance.
5
Establish the long-term postoperative surveillance plan.
Monthly beta-hCG monitoring for 6 months.
Once the initial weekly levels are negative, extended monthly surveillance is necessary to quickly detect late-onset gestational trophoblastic neoplasia.
6
Determine the endpoint of surveillance and management.
Clearance to attempt pregnancy.
Only after completing the full surveillance period without recurrence can the patient safely conceive, as an early new pregnancy would cause a rise in beta-hCG that could mask a recurrence.

Key Concept

Diagnosis, Management, and Surveillance of Complete Hydatidiform Mole
Question 847Question →

A healthy 24-year-old primigravida in her second trimester visits the clinic after noticing a painless, indurated ulcer on her labia majora. Her medical history is notable for a severe anaphylactic reaction, characterized by respiratory distress and hypotension, following amoxicillin exposure during childhood. Arrange the following clinical steps in the most appropriate chronological order to accurately diagnose and definitively manage this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is to first confirm the diagnosis with serology, then admit the patient to a monitored setting, perform penicillin desensitization, administer intramuscular benzathine penicillin G, and finally monitor for a Jarisch-Herxheimer reaction.
This chronological sequence follows established guidelines for managing syphilis in a pregnant patient with a severe penicillin allergy. First, the clinical suspicion of a syphilitic chancre must be confirmed with appropriate serology. Second, because alternative regimens (e.g., doxycycline) are contraindicated or ineffective for the fetus, the patient must receive penicillin. Given her history of anaphylaxis, she must be admitted to an ICU or similarly equipped setting. Third, a strict penicillin desensitization protocol is executed to safely deplete IgE antibodies. Fourth, the therapeutic dose of intramuscular benzathine penicillin G is administered. Finally, the patient is monitored for the Jarisch-Herxheimer reaction, an acute inflammatory response to spirochete lysis that can trigger preterm labor or fetal distress in pregnant women.

Step-by-Step Solution

1
Obtain nontreponemal and treponemal serology.
Confirmation of Treponema pallidum infection.
The painless chancre is highly suspicious for primary syphilis, but definitive diagnosis guides the high-risk management pathway.
2
Admit to an intensive care or step-down unit.
The patient is placed in a setting with continuous monitoring and airway support.
Penicillin is the only antibiotic that reliably crosses the placenta to treat fetal syphilis. Because of her anaphylaxis history, preparation for a severe allergic response is mandatory.
3
Perform penicillin desensitization.
Temporary tolerance to penicillin is established.
Gradually increasing micro-doses of penicillin safely cross-links IgE receptors without triggering widespread mast cell degranulation.
4
Administer intramuscular benzathine penicillin G.
Curative antimicrobial therapy is delivered.
Desensitization allows the safe administration of the required therapeutic dose to cure maternal infection and prevent congenital transmission.
5
Monitor for maternal fever, myalgias, and fetal heart rate changes.
Early identification of a Jarisch-Herxheimer reaction.
Rapid spirochete destruction releases lipoproteins that trigger a systemic inflammatory response, which can cause preterm labor or fetal distress in pregnant women.

Key Concept

Pregnant patients with syphilis and a severe penicillin allergy must undergo inpatient penicillin desensitization, as penicillin is the only antibiotic proven to reliably cross the placenta and prevent congenital syphilis.
Question 848Question →

A 27-year-old multiparous patient at 39 weeks gestation has just delivered a 4,150 g (9 lb 2 oz) neonate vaginally. During the delivery of the placenta, the resident applies continuous umbilical cord traction while the uterus is flaccid. The patient suddenly cries out in severe lower abdominal pain, followed by a massive gush of vaginal blood. Her blood pressure is 76/40 mm Hg, and her pulse is 134/min. Physical examination reveals a beefy red, globular mass protruding through the vaginal introitus. The uterine fundus is not palpable on transabdominal examination. An initial attempt to manually push the mass back into the pelvis is unsuccessful because the lower uterine segment and cervix are firmly contracted around the prolapsed tissue. Arrange the following steps in the most appropriate sequential order to manage this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence involves stopping uterotonics and resuscitating, administering a uterine relaxant, manually replacing the uterus, and finally administering uterotonics to maintain uterine tone.
Uterine inversion is a life-threatening obstetric emergency characterized by the collapse of the uterine fundus into the uterine cavity or through the cervix, often presenting with severe hemorrhage, pain, and shock. The presentation of a beefy red vaginal mass and absent palpable fundus after excessive cord traction is classic. Management must follow a strict algorithm. First, maternal resuscitation with fluids is initiated while simultaneously discontinuing any uterotonics (e.g., oxytocin), as these agents contract the lower uterine segment and cervix, thereby trapping the inverted fundus. If initial manual replacement fails due to a contracted cervical ring, a uterine relaxant (such as nitroglycerin, terbutaline, or general anesthetics) must be administered. Once relaxed, the physician manually replaces the fundus. Only after the uterus is fully restored to its normal anatomic position should uterotonics (e.g., oxytocin infusion, misoprostol) be administered to ensure the uterus clamps down, which prevents reinversion and controls bleeding.

Step-by-Step Solution

1
Discontinue any ongoing uterotonic agents and begin aggressive intravenous fluid resuscitation.
Prevents further tightening of the cervical ring and treats hypovolemic shock.
Uterotonics worsen the constriction ring around the inverted uterus, and the patient is hypotensive due to acute hemorrhage.
2
Administer a rapid-acting uterine relaxant (e.g., intravenous nitroglycerin).
Relaxes the uterus and the constricted cervical ring.
Initial manual replacement failed; a relaxant is required to soften the cervical ring to permit the passage of the inverted fundus.
3
Manually replace the inverted uterus into its normal anatomic position within the pelvis.
Restores normal pelvic anatomy and stops the primary cause of hemorrhage.
The anatomical distortion must be corrected to stop bleeding, which is now possible due to the administered uterine relaxant.
4
Administer high-dose uterotonics and initiate continuous bimanual massage.
The uterus becomes firm and well-contracted.
A well-contracted uterus prevents the fundus from reinverting and mechanically compresses the bleeding myometrial vessels.

Key Concept

The sequential management of a uterine inversion involves maternal resuscitation with discontinuation of uterotonics, administration of uterine relaxants if initial manual replacement fails, manual replacement of the uterus, and finally administration of uterotonics to prevent recurrence.
Question 849Question →

Evaluate the following four individuals presenting to the gynecology clinic for evaluation of absent menses. Pair their distinct physical, historical, and laboratory findings with the correct pathophysiologic diagnosis.

Click a left item, then click its matching right item

Items

A 16-year-old with absent menarche, Tanner stage IV breasts, absent axillary and pubic hair, a blind vaginal pouch, and a 46,XY karyotype.
A 19-year-old with primary amenorrhea, normal secondary sexual characteristics, visible bilateral ovaries on ultrasound, an absent uterus, and a 46,XX karyotype.
A 28-year-old with secondary amenorrhea, extreme fatigue, and failure to lactate following a complicated delivery involving massive obstetric hemorrhage.
A 32-year-old with secondary amenorrhea who fails to have withdrawal bleeding after a progestin challenge, with a history of a recent dilation and curettage for a missed abortion.

Matches

Show answer & explanation

Answer

Each clinical presentation is matched to its anatomic, genetic, or acquired etiology based on key physical, hormonal, and historical clues.
Matching these distinct clinical syndromes correctly requires distinguishing between genetic receptor defects, embryologic duct malformations, ischemic tissue damage, and iatrogenic mechanical scarring as the primary etiologies of absent menses.

Step-by-Step Solution

1
Analyze the 16-year-old's presentation.
Identified a 46,XY karyotype, breast development, but absent pubic hair.
These findings are diagnostic of complete androgen insensitivity syndrome, where testosterone is aromatized to estrogen (forming breasts) but androgen receptors fail to respond (causing lack of body hair).
2
Analyze the 19-year-old's presentation.
Identified a 46,XX karyotype with an absent uterus but normal ovaries.
The isolated absence of Müllerian structures with normal female genetics and ovarian function defines Müllerian agenesis.
3
Analyze the 28-year-old's presentation.
Identified systemic endocrine failure following massive obstetric hemorrhage.
Postpartum pituitary ischemia (Sheehan syndrome) causes panhypopituitarism, explaining the agalactorrhea, fatigue, and amenorrhea.
4
Analyze the 32-year-old's presentation.
Identified secondary amenorrhea refractory to progesterone following uterine instrumentation.
Failure to bleed after a progestin challenge indicates a structural outflow tract issue, typical of intrauterine synechiae (Asherman syndrome) caused by prior curettage.

Key Concept

The diagnostic differentiation of primary and secondary amenorrhea relies heavily on the presence of secondary sexual characteristics, karyotype analysis, ultrasound findings, and obstetric or surgical history.
Question 850Question →

A 28-year-old woman, gravida 1, para 0, presents for her initial prenatal visit at 10 weeks gestation. She reports mild fatigue and frequent urination but otherwise feels well. Her medical history is unremarkable. She works as a kindergarten teacher. Temperature is 37.0°C (98.6°F), blood pressure is 110/70 mm Hg, pulse is 84/min, and respiratory rate is 18/min.

Laboratory results show:
- Hemoglobin: 11.2 g/dL
- Mean corpuscular volume: 88 μ\mu m³
- Leukocyte count: 8,500/mm³
- Urine dipstick: positive for leukocyte esterase, negative for nitrites
- Urine culture: 10510^5 CFU/mL of *Escherichia coli*

Antibiotic susceptibilities for the isolate show sensitivity to amoxicillin, cephalexin, and levofloxacin.

The patient is concerned about catching the flu from her students and requests the intranasal influenza vaccine today. When told she needs treatment for her urinary findings, she states she is afraid to take antibiotics because she read they might harm the baby.

Which of the following is the most appropriate next step in the management of this patient?

Show answer & explanation

Answer: Provide counseling on the safety of oral cephalexin and recommend the inactivated intramuscular influenza vaccine.

Answer

Provide counseling on the safety of oral cephalexin and recommend the inactivated intramuscular influenza vaccine.
The correct answer provides counseling on the safety of oral cephalexin and recommends the inactivated intramuscular influenza vaccine. This patient has asymptomatic bacteriuria (ASB), defined as ≥105\ge 10^5 CFU/mL of a uropathogen without symptoms. Unlike in non-pregnant patients, ASB in pregnancy must be treated to prevent progression to pyelonephritis and adverse outcomes like preterm birth. Because the patient is hesitant, the most appropriate next step is to provide informed counseling regarding the safety of narrow-spectrum antibiotics like cephalexin (which is safe in all trimesters). Additionally, all pregnant women should receive the influenza vaccine during flu season; however, they must receive the inactivated intramuscular version, as the live-attenuated intranasal version is contraindicated.

Step-by-Step Solution

1
Analyze the urinary findings and maternal history.
The patient has >100,000 CFU/mL of E. coli in her urine but no symptoms, diagnosing asymptomatic bacteriuria (ASB). She is pregnant.
ASB requires treatment in pregnancy to prevent progression to pyelonephritis and complications like preterm labor.
2
Evaluate the patient's concerns regarding medication.
The patient expressed fear of fetal harm from antibiotics.
Before accepting a refusal of care, the physician's duty is to provide evidence-based counseling on safe treatment options (like cephalexin) to ensure informed decision-making.
3
Assess the request for the influenza vaccine.
She requested the intranasal vaccine.
The intranasal flu vaccine is live-attenuated and contraindicated in pregnancy. The inactivated intramuscular vaccine must be recommended instead, as it is safe and indicated in all trimesters.
4
Interpret the hematologic parameters.
Her hemoglobin is 11.2 g/dL, which is normal for the first trimester (cutoff is 11.0 g/dL).
Normal physiologic dilutional anemia does not require therapeutic iron supplementation.

Key Concept

In routine prenatal care, asymptomatic bacteriuria must be treated with safe, narrow-spectrum antibiotics (e.g., cephalexin). Pregnant patients should receive the inactivated intramuscular influenza vaccine; live-attenuated vaccines are contraindicated. Mild drops in hemoglobin (≥\ge 11.0 g/dL in the first trimester) reflect normal physiologic dilutional anemia.
Question 851Question →

Seeking medical care for an unexpected return of vaginal bleeding, a 71-year-old retired teacher arrives at the gynecology office. She reports noticing red spotting on her undergarments and toilet tissue over the past two weeks. The patient transitioned through menopause 20 years ago and has not experienced any vaginal bleeding since. Her past medical history is significant for well-controlled type 2 diabetes mellitus, essential hypertension, and obesity. Current medications include metformin and lisinopril. On physical examination, her blood pressure is 138/82 mmHg138/82 \text{ mmHg}, and her body mass index is 33 kg/m233 \text{ kg/m}^2. Speculum examination shows pale, dry vaginal walls without lacerations, but a small pool of dark blood is visible at the posterior fornix. Bimanual examination reveals a mobile, non-tender, anteverted uterus that is normal in size for her age. A transvaginal ultrasound is performed in the office, demonstrating an endometrial thickness of 11 mm11 \text{ mm} with cystic changes. The adnexa are unremarkable bilaterally. Which of the following is the most appropriate next step in the clinical management of this patient?

Show answer & explanation

Answer: Endometrial biopsy

Answer

Endometrial biopsy
The most appropriate next step for this patient is an endometrial biopsy. She presents with postmenopausal bleeding and possesses multiple risk factors for endometrial cancer, including unopposed estrogen exposure related to obesity, type 2 diabetes mellitus, and advanced age. Her transvaginal ultrasound reveals an endometrial thickness of 11 mm11 \text{ mm}. In a postmenopausal patient, an endometrial stripe greater than 4 mm4 \text{ mm} is considered abnormal and highly suspicious for endometrial hyperplasia or malignancy. Therefore, prompt histological evaluation via an outpatient endometrial biopsy is mandatory to establish a definitive tissue diagnosis.

Step-by-Step Solution

1
Identify the patient's primary presenting symptom and associated risk factors.
The patient is a 71-year-old postmenopausal woman with new-onset vaginal bleeding, obesity, and type 2 diabetes mellitus.
These factors place her at a significantly increased risk for endometrial cancer.
2
Analyze the results of the initial diagnostic imaging.
The transvaginal ultrasound demonstrates an endometrial thickness of 11 mm.
In postmenopausal women, an endometrial stripe thicker than 4 mm is considered abnormal and highly suspicious for underlying pathology.
3
Determine the appropriate clinical guideline for this presentation.
Guidelines dictate that abnormal postmenopausal bleeding combined with a thickened endometrial stripe requires direct tissue sampling.
An outpatient endometrial biopsy is the definitive first-line test to histologically diagnose or rule out endometrial hyperplasia and carcinoma.

Key Concept

Evaluation of Postmenopausal Bleeding
Question 852Question →

A 24-year-old woman returns to the clinic to review laboratory results. Three days ago, she presented with new-onset dyspareunia and an increased yellowish vaginal discharge. At that time, her temperature was 37.1°C (98.8°F), blood pressure was 112/70 mm Hg, and pulse was 76/min. Pelvic examination revealed a markedly friable cervix with mucopurulent exudate, but no cervical motion or adnexal tenderness. A cervical swab was sent for testing, and the patient opted to defer empiric antibiotic therapy until a definitive diagnosis was made. Today, her nucleic acid amplification test (NAAT) results return positive for *Neisseria gonorrhoeae* and negative for *Chlamydia trachomatis*. Her medical history is significant for a severe allergic reaction to ceftriaxone, characterized by hypotension and respiratory distress requiring epinephrine. Based on current guidelines, which of the following is the most appropriate pharmacotherapy for this patient?

Show answer & explanation

Answer: Intramuscular gentamicin and oral azithromycin

Answer

Intramuscular gentamicin and oral azithromycin
The patient has isolated gonococcal cervicitis, as confirmed by NAAT. The standard recommended treatment for uncomplicated *Neisseria gonorrhoeae* infection is a single dose of intramuscular ceftriaxone. However, this patient has a history of anaphylaxis to ceftriaxone, making it strictly contraindicated. According to current Centers for Disease Control and Prevention (CDC) guidelines, the preferred alternative regimen for patients with a severe cephalosporin (or severe penicillin) allergy is a single dose of intramuscular gentamicin (240 mg) combined with a single large dose of oral azithromycin (2 g). This specific dual regimen effectively eradicates the gonococcal infection while completely circumventing the cephalosporin allergy.

Step-by-Step Solution

1
Analyze the patient's diagnostic results.
The NAAT is positive for Neisseria gonorrhoeae and negative for Chlamydia trachomatis.
This confirms a diagnosis of isolated gonococcal cervicitis, requiring targeted pathogen-specific therapy rather than empiric broad-spectrum coverage.
2
Evaluate the patient's medical history for contraindications.
The patient has a documented anaphylactic reaction to ceftriaxone.
Ceftriaxone, the standard first-line treatment for gonorrhea, is strictly contraindicated due to the risk of a life-threatening allergic response.
3
Determine the appropriate alternative pharmacotherapy.
Current guidelines recommend a single dose of intramuscular gentamicin combined with a single dose of oral azithromycin.
This alternative dual-drug regimen effectively treats the infection while circumventing the cephalosporin allergy and minimizing the risk of developing further antibiotic resistance.

Key Concept

Treatment of uncomplicated gonococcal cervicitis in patients with a severe cephalosporin allergy requires an alternative regimen of intramuscular gentamicin combined with oral azithromycin.
Question 853Question →

A healthy nulliparous patient at 6 weeks gestation by last menstrual period presents to the obstetrics clinic to establish care following a positive home pregnancy test. She is 27 years old, has an unremarkable medical history, and takes only a daily prenatal vitamin. The patient is eager to understand the timeline of her upcoming evaluations. Arrange the following routine prenatal assessments and interventions in the correct chronological sequence they should be performed throughout an uncomplicated pregnancy.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: dating ultrasound (6-10 weeks), first-trimester aneuploidy screening (10-14 weeks), anatomic survey (18-22 weeks), oral glucose challenge test (24-28 weeks), and group B Streptococcus culture (36-38 weeks).
Routine prenatal care follows a standardized chronological timeline to optimize maternal and fetal outcomes. Early in the first trimester (6-10 weeks), a transvaginal ultrasound is typically performed to confirm viability and establish highly accurate pregnancy dating. Between 10 and 14 weeks, first-trimester combined screening (nuchal translucency and serum markers) is offered for aneuploidy risk assessment. The comprehensive fetal anatomic survey is optimally performed between 18 and 22 weeks, as fetal structures are adequately developed for visualization. Universal screening for gestational diabetes with a 50-g oral glucose challenge test is conducted between 24 and 28 weeks due to the physiological peak in insulin resistance caused by placental hormones. Finally, rectovaginal screening for Group B Streptococcus is performed between 36 and 38 weeks to maximize the predictive value for intrapartum colonization status.

Step-by-Step Solution

1
Determine the timing for the initial viability and dating scan.
First trimester, typically 6-10 weeks.
Establishing accurate gestational age and confirming viability is the foundational first step in prenatal care.
2
Identify the window for first-trimester aneuploidy screening.
10-14 weeks.
Nuchal translucency and specific maternal serum markers must be evaluated within this narrow gestational window for accurate risk calculation.
3
Identify the timing for the comprehensive anatomic survey.
18-22 weeks.
Fetal structures, including the heart and central nervous system, are best visualized transabdominally at this mid-trimester stage.
4
Determine the optimal window for universal gestational diabetes screening.
24-28 weeks.
Placental hormone production (such as human placental lactogen) peaks during this time, maximizing insulin resistance and the detection of gestational diabetes.
5
Determine the timing for group B Streptococcus (GBS) screening.
36-38 weeks.
GBS screening is conducted late in the third trimester to accurately predict intrapartum colonization status and guide the need for antibiotic prophylaxis.

Key Concept

Chronological timeline of routine prenatal care interventions in an uncomplicated pregnancy.
Estimated Time:1m 0s
Question 854Question →

Match each patient's clinical presentation with the most appropriate next step in diagnosis or management.

Click a left item, then click its matching right item

Items

65-year-old woman presenting with postmenopausal bleeding and an endometrial thickness of 3 mm on transvaginal ultrasound
62-year-old woman presenting with postmenopausal bleeding and an endometrial thickness of 8 mm on transvaginal ultrasound
38-year-old woman whose routine cervical cytology reports atypical glandular cells (AGC)
48-year-old woman diagnosed with complex atypical endometrial hyperplasia who has completed childbearing
29-year-old woman diagnosed with grade 1, stage IA endometrial adenocarcinoma who desires to preserve fertility

Matches

Show answer & explanation

Answer

The 65-year-old with a 3-mm stripe is matched with reassurance and observation. The 62-year-old with an 8-mm stripe requires an office endometrial biopsy. The 38-year-old with AGC requires colposcopy, endocervical curettage, and endometrial biopsy. The 48-year-old with atypical hyperplasia is treated with hysterectomy and bilateral salpingo-oophorectomy. The 29-year-old with early-stage cancer desiring fertility is matched with high-dose progestin therapy.
Gynecologic oncology guidelines rely heavily on risk stratification based on age, imaging findings, and biopsy results. In postmenopausal bleeding, ultrasound is an effective triage tool: a stripe ≤ 4 mm requires no further intervention, whereas > 4 mm mandates biopsy. Atypical glandular cells on a Pap smear present a risk for both cervical and endometrial malignancies, requiring dual evaluation in women 35 and older. Definitive management of atypical hyperplasia is hysterectomy due to cancer risk, but early-grade cancers in young women can be medically suppressed with progestins to preserve fertility.

Step-by-Step Solution

1
Evaluate the 65-year-old with postmenopausal bleeding and a 3-mm endometrial stripe.
Observation is indicated.
An endometrial thickness of 4 mm or less reliably rules out endometrial cancer in postmenopausal women with bleeding.
2
Evaluate the 62-year-old with postmenopausal bleeding and an 8-mm stripe.
Endometrial biopsy is indicated.
An endometrial thickness > 4 mm in a postmenopausal woman is abnormal and requires histologic evaluation.
3
Assess the 38-year-old with AGC on her Pap smear.
Colposcopy, ECC, and endometrial biopsy are indicated.
AGC can originate from the cervix or the endometrium; all women 35 and older with AGC require comprehensive sampling of both areas.
4
Determine the management for the 48-year-old with atypical hyperplasia who has finished childbearing.
Total hysterectomy with bilateral salpingo-oophorectomy is indicated.
This is a precancerous lesion with a high rate of progression to malignancy, making definitive surgical management the standard of care.
5
Formulate a plan for the 29-year-old with grade 1 endometrial cancer.
High-dose progestins are indicated.
Highly motivated young women with early, well-differentiated disease can use medical management to preserve the uterus for future childbearing.

Key Concept

Evidence-based management of abnormal uterine bleeding, cervical cytology abnormalities, and endometrial neoplasia based on patient risk factors.
Question 855Question →

A 24-year-old nulliparous patient presents to the labor unit at 39 weeks and 4 days of gestation with painful uterine contractions. Her prenatal course was unremarkable. On admission, her cervical examination demonstrates 5 cm of dilation, 90% effacement, and -1 station. Two hours later, she requests neuraxial analgesia, and a continuous epidural infusion is successfully initiated. Shortly after the procedure, the patient complains of dizziness and nausea. Her blood pressure drops to 80/45 mm Hg from a baseline of 118/74 mm Hg, and her heart rate increases to 112/min. Concurrently, the continuous fetal monitor demonstrates a sudden decrease in the fetal heart rate baseline from 145/min to 85/min, which persists for 4 minutes with minimal variability. The nursing staff immediately places the patient in the left lateral decubitus position and administers a rapid intravenous bolus of isotonic crystalloid, but her blood pressure only marginally improves to 84/48 mm Hg. The fetal heart rate remains at 85/min. Which of the following is the most appropriate next step in the management of this patient?

Show answer & explanation

Answer: Intravenous ephedrine

Answer

Intravenous ephedrine
The correct answer is intravenous ephedrine. The patient has developed maternal hypotension secondary to epidural anesthesia. Epidurals cause sympathetic blockade, which leads to peripheral vasodilation, pooling of blood in the lower extremities, and reduced venous return. This cascade decreases maternal cardiac output and placental perfusion, resulting in fetal hypoxia and a prolonged fetal heart rate deceleration. Initial management of post-epidural hypotension includes maternal repositioning (specifically left lateral uterine displacement to relieve aortocaval compression) and a rapid intravenous fluid bolus. Because these conservative measures were insufficient to restore maternal blood pressure in this patient, the most appropriate next step is the administration of a vasopressor, such as intravenous ephedrine or phenylephrine. Restoring maternal blood pressure will resolve the uteroplacental insufficiency and typically leads to the rapid recovery of the fetal heart rate.

Step-by-Step Solution

1
Identify the cause of the fetal heart rate deceleration.
The patient developed severe hypotension immediately following the initiation of epidural analgesia.
Sympathetic blockade from the epidural causes vasodilation and decreased venous return, leading to reduced maternal cardiac output, diminished placental perfusion, and a prolonged fetal deceleration.
2
Evaluate the interventions already performed.
The patient was repositioned to the left lateral decubitus position and received an intravenous fluid bolus.
These are the initial non-pharmacologic steps to relieve aortocaval compression and increase preload, attempting to restore maternal blood pressure.
3
Determine the next appropriate step for refractory maternal hypotension.
Administer a vasopressor such as intravenous ephedrine or phenylephrine.
Restoring maternal blood pressure with a vasopressor is necessary to resolve the uteroplacental insufficiency and the fetal deceleration, and must be attempted before considering operative delivery.

Key Concept

The management of prolonged fetal heart rate decelerations secondary to post-epidural maternal hypotension involves sequential intrauterine resuscitation: maternal repositioning, intravenous fluid boluses, and if refractory, the administration of a vasopressor (ephedrine or phenylephrine).
Estimated Time:1m 30s
Question 856Question →

Match each clinical presentation of a suspected gynecologic infection to the most appropriate initial pharmacologic management based on current guidelines.

Click a left item, then click its matching right item

Items

A 21-year-old non-pregnant woman presents with mild lower abdominal pain and cervical motion tenderness. She is afebrile and tolerating oral intake.
A 26-year-old woman presents with severe pelvic pain, intractable vomiting, and a temperature of 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}). Ultrasound reveals a 6-centimeter complex adnexal mass.
A 30-year-old woman at 14 weeks gestation complains of a malodorous, thin, grayish-white vaginal discharge. Vaginal pH is 5.5 and an amine odor is present on KOH prep.
A 23-year-old asymptomatic woman tests positive for *Chlamydia trachomatis* and negative for *Neisseria gonorrhoeae* on routine nucleic acid amplification testing.

Matches

Show answer & explanation

Answer

Uncomplicated PID is treated with IM ceftriaxone plus oral doxycycline and metronidazole. Tubo-ovarian abscesses require inpatient IV cefoxitin and doxycycline. Bacterial vaginosis in pregnancy is treated with oral metronidazole. Isolated chlamydial infection is treated with a 7-day course of oral doxycycline.
Each clinical presentation necessitates a targeted approach based on current CDC guidelines. Uncomplicated PID requires outpatient coverage for gonorrhea, chlamydia, and anaerobes (ceftriaxone + doxycycline + metronidazole). Complicated PID, such as a tubo-ovarian abscess, necessitates hospital admission and IV antibiotics (cefoxitin + doxycycline). Bacterial vaginosis is safely treated with metronidazole during pregnancy. Finally, uncomplicated chlamydia is best treated with a 7-day course of oral doxycycline.

Step-by-Step Solution

1
Identify the underlying diagnosis and disease severity for each clinical vignette.
The vignettes represent uncomplicated PID, a tubo-ovarian abscess (complicated PID), bacterial vaginosis in pregnancy, and isolated chlamydial cervicitis.
Accurate diagnosis and severity staging dictate both the treatment setting and the necessary antimicrobial spectrum.
2
Determine the appropriate treatment setting based on clinical stability.
The patient with vomiting and a complex adnexal mass requires hospitalization, while the others can be managed in the outpatient setting.
Patients with a tubo-ovarian abscess, intractable vomiting, or high fever require close monitoring and parenteral antibiotics.
3
Select the guideline-concordant antimicrobial regimen covering the most likely pathogens for each condition.
Match the outpatient PID to broad-spectrum oral/IM therapy, the TOA to IV therapy, the pregnant BV patient to metronidazole, and the chlamydia patient to doxycycline.
Regimens must adhere to current CDC guidelines to ensure high cure rates and prevent reproductive sequelae.

Key Concept

Pharmacologic management of gynecologic infections is determined by the specific pathogen, disease severity (e.g., uncomplicated PID vs. TOA), and specific patient factors (e.g., pregnancy).
Question 857Question →

Review the following clinical assessments of labor progress. According to current American College of Obstetricians and Gynecologists (ACOG) guidelines, match each clinical scenario to its correct diagnostic classification.

Click a left item, then click its matching right item

Items

A nulliparous patient at 4040 weeks gestation with regular uterine contractions has remained at 44 cm of cervical dilation for 2222 hours.
A multiparous patient at 3939 weeks gestation with spontaneous membrane rupture has remained at 77 cm of cervical dilation for 44 hours despite an intrauterine pressure catheter confirming 240240 Montevideo units.
A nulliparous patient at 3838 weeks gestation with epidural analgesia has been pushing with each contraction for 44 hours without any descent of the fetal head past the +1+1 station.
A multiparous patient at 4141 weeks gestation experiences a gradual change in cervical dilation from 66 cm to 77 cm over a period of 33 hours with regular uterine contractions.

Matches

Show answer & explanation

Answer

The correct matches align each clinical presentation with specific ACOG thresholds for labor abnormalities: 2222 hours at 44 cm is a Prolonged latent phase; 44 hours at 77 cm with adequate contractions is an Active phase arrest; 44 hours of pushing with an epidural in a nullipara is a Second stage arrest; and slow progression from 66 to 77 cm over 33 hours is a Protracted active phase.
Labor abnormalities are classified by precise cervical dilation milestones and time thresholds. A latent phase >20>20 hours (nullipara) is prolonged. In the active phase (≥6\ge 6 cm), no change for 44 hours with adequate contractions defines arrest, while slow change constitutes protraction. In the second stage, 44 hours of pushing (nullipara with epidural) defines arrest.

Step-by-Step Solution

1
Determine the current stage and phase of labor for each patient based on cervical dilation and pushing status.
Dilation less than 66 cm indicates the latent phase; dilation of 66 cm or more indicates the active phase; complete dilation (1010 cm) marks the onset of the second stage.
Labor guidelines apply different time constraints depending on the precise phase of labor.
2
Compare the elapsed time in the scenario against ACOG diagnostic thresholds for parity and epidural status.
The nulliparous latent phase exceeds the 2020-hour limit. The active phase lack of change meets the 44-hour adequate contraction rule for arrest. The second stage duration meets the 44-hour limit for a nullipara with an epidural.
Accurate application of numerical thresholds is required to distinguish between normal labor, protracted labor, and arrested labor.

Key Concept

Abnormalities of Labor Progress and ACOG Diagnostic Criteria
Estimated Time:1m 0s
Question 858Question →

Standard prenatal care involves a strict schedule of laboratory evaluations and prophylactic interventions based on gestational age to optimize maternal and fetal outcomes. Match each clinical presentation during a routine, uncomplicated pregnancy with the most appropriate next step in prenatal screening or management.

Click a left item, then click its matching right item

Items

A pregnant woman at 12 weeks of gestation presenting for early risk assessment.
A pregnant woman at 25 weeks of gestation presenting for mid-pregnancy metabolic evaluation.
An Rh(D)-negative pregnant woman at 28 weeks of gestation with an uncomplicated clinical course.
A pregnant woman at 36 weeks of gestation preparing for term labor and delivery.

Matches

Show answer & explanation

Answer

The correct pairings align 12 weeks with aneuploidy screening (nuchal translucency and serum markers), 25 weeks with gestational diabetes screening (50-g glucose load), 28 weeks with prophylactic anti-D immune globulin for Rh(D)-negative status, and 36 weeks with rectovaginal Group B Streptococcus screening.
Routine prenatal care follows a standardized timeline to maximize maternal and fetal safety. First-trimester aneuploidy screening (nuchal translucency, PAPP-A, beta-hCG) must be performed between 11 and 14 weeks. Gestational diabetes screening is conducted between 24 and 28 weeks because human placental lactogen and other hormones cause peaking insulin resistance during this period. Anti-D immune globulin is routinely administered at 28 weeks to Rh(D)-negative women to prevent maternal alloimmunization prior to delivery. Group B Streptococcus screening is performed via rectovaginal culture at 36 to 38 weeks because colonization status fluctuates; testing close to the expected time of delivery provides the highest predictive value for the need of intrapartum antibiotic prophylaxis.

Step-by-Step Solution

1
Determine the appropriate screening for a patient at 12 weeks of gestation.
Match with assessment of fetal nuchal translucency and serum PAPP-A/beta-hCG.
First-trimester aneuploidy screening is specifically timed for the 11 to 14 week window to evaluate chromosomal risk.
2
Determine the appropriate screening for a patient at 25 weeks of gestation.
Match with administration of a 50-g oral glucose load.
Universal screening for gestational diabetes is optimally performed between 24 and 28 weeks when placental hormone-driven insulin resistance becomes clinically significant.
3
Determine the appropriate intervention for an Rh(D)-negative patient at 28 weeks of gestation.
Match with intramuscular administration of prophylactic anti-D immune globulin.
Routine prophylaxis is given at 28 weeks to provide passive immunity against alloimmunization during the third trimester, when the risk of fetomaternal hemorrhage increases.
4
Determine the appropriate screening for a patient at 36 weeks of gestation.
Match with collection of a rectovaginal swab for Group B Streptococcus.
Universal GBS screening is conducted between 36 and 38 weeks because colonization is transient, and testing within 5 weeks of expected delivery most accurately predicts colonization at the time of birth.

Key Concept

Routine Prenatal Screening Timeline
Estimated Time:1m 0s
Question 859Question →

A 27-year-old nulliparous woman at 15 weeks gestation comes to the clinic for a scheduled prenatal visit. She reports feeling well and has no current health concerns. Upon specific questioning, she denies any vaginal itching, burning, malodor, or pelvic pain. Her vital signs are within normal limits. Speculum examination reveals a normal-appearing, closed cervix and a moderate amount of thin, homogenous, grayish-white vaginal discharge pooling in the posterior fornix. The patient states this discharge has been present for several weeks but does not bother her. Point-of-care testing of the vaginal fluid demonstrates a pH of 5.5. Addition of 10% potassium hydroxide to the fluid produces a strong amine odor. Microscopic evaluation of a saline wet mount reveals numerous sloughed squamous epithelial cells with their margins completely obscured by adherent coccobacilli. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Continue routine prenatal care without pharmacotherapy

Answer

The most appropriate management is to continue routine prenatal care without pharmacotherapy, as treating asymptomatic bacterial vaginosis in pregnancy is not recommended.
The correct approach is expectant management (continuing routine prenatal care without pharmacotherapy). This patient's presentation fulfills all four Amsel criteria for bacterial vaginosis (BV): homogenous discharge, pH > 4.5, positive amine odor, and clue cells. However, she is entirely asymptomatic. In pregnant women, routine treatment of asymptomatic BV is not recommended because clinical trials have shown it does not reduce the risk of preterm labor or other adverse obstetric outcomes. Therefore, observation is the standard of care.

### Vaginitis Management Summary
ConditionVaginal pHMicroscopic FindingsManagement in Pregnancy
Bacterial Vaginosis> 4.5Clue cellsTreat only if symptomatic
Vulvovaginal Candidiasis4.0 - 4.5Pseudohyphae, budding yeastTopical azoles (avoid oral fluconazole)
Trichomoniasis> 4.5Motile, flagellated protozoaOral metronidazole

Step-by-Step Solution

1
Diagnose the vaginal discharge based on clinical and microscopic findings.
The patient has thin, homogenous discharge, a pH > 4.5, a positive whiff test, and clue cells on wet mount. These fulfill Amsel criteria, confirming the diagnosis of bacterial vaginosis (BV).
Accurate identification of the vaginal dysbiosis is required before determining management.
2
Assess the patient's symptomatic status and obstetric context.
The patient is at 15 weeks gestation and explicitly denies any bothersome symptoms (no itching, burning, or malodor from her perspective).
The necessity of treating BV heavily depends on whether the patient is symptomatic and her pregnancy status.
3
Apply current treatment guidelines for bacterial vaginosis in pregnancy.
Guidelines recommend against screening for and treating asymptomatic BV in pregnant women, as antibiotic therapy has not been shown to prevent preterm delivery or other adverse outcomes in this population.
Antibiotic stewardship dictates avoiding unnecessary pharmacotherapy, especially during pregnancy when fetal exposure is a consideration.

Key Concept

Asymptomatic Bacterial Vaginosis in Pregnancy
Question 860Question →

A 2424-year-old woman, gravida 11, para 00, at 3030 weeks gestation comes to the clinic reporting a sensation of breathlessness. The patient states she feels like she "cannot take a deep enough breath," especially when sitting quietly. She denies cough, wheezing, chest pain, or leg swelling. Her medical history is unremarkable, and her only medication is a daily prenatal vitamin. Blood pressure is 112/68112/68 mm Hg, pulse is 8888/min, respirations are 1616/min, and pulse oximetry is 99%99\% on room air. Physical examination reveals clear lungs bilaterally and no heart murmurs. The fundal height is 3030 cm. If an arterial blood gas were obtained from this patient, which of the following sets of values would most likely be expected?

Show answer & explanation

Answer: pH 7.447.44, PaCO 2_2 3030 mm Hg, HCO 3−_3^- 2020 mEq/L

Answer

pH 7.44, PaCO2 30 mm Hg, HCO3- 20 mEq/L (Chronic compensated respiratory alkalosis)
The correct response reflects chronic compensated respiratory alkalosis. During pregnancy, elevated circulating progesterone directly stimulates the medullary respiratory center. This leads to a 30%30\% to 40%40\% increase in tidal volume, which consequently increases minute ventilation (respiratory rate typically remains normal). The hyperventilation causes an increased blow-off of carbon dioxide, lowering the PaCO 2_2 to approximately 2828-3232 mm Hg (primary respiratory alkalosis). Because this is a chronic state, the kidneys compensate by increasing the excretion of bicarbonate, lowering serum HCO 3−_3^- to 1818-2121 mEq/L. The resulting arterial pH is typically normal or slightly alkaline (7.407.40-7.457.45). This physiological hyperventilation creates a subjective sensation of breathlessness, known as physiologic dyspnea of pregnancy, which is benign.

Step-by-Step Solution

1
Interpret the patient's presentation of breathlessness during a normal pregnancy.
The patient is experiencing "physiologic dyspnea of pregnancy," common in the second and third trimesters, with normal vital signs and a reassuring physical exam.
Dyspnea in pregnancy without other pathological signs (e.g., normal oxygen saturation, clear lungs) points toward normal maternal physiologic adaptations rather than underlying cardiopulmonary disease.
2
Determine the pathophysiological respiratory changes in normal pregnancy.
Elevated progesterone levels directly stimulate the medullary respiratory center, causing an increase in tidal volume (and thus minute ventilation), while the respiratory rate remains largely unchanged.
Increased minute ventilation is required to meet the increased metabolic demands of the fetus and mother.
3
Predict the resulting arterial blood gas (ABG) alterations.
Increased minute ventilation leads to increased CO2 blow-off (PaCO2 drops to 28-32 mm Hg). The kidneys compensate by excreting bicarbonate (HCO3- drops to 18-21 mEq/L). The resulting pH is normal to slightly alkalemic (7.40-7.44).
Pregnancy induces a state of chronic primary respiratory alkalosis with appropriate metabolic compensation.

Key Concept

Normal pregnancy involves progesterone-mediated increases in tidal volume and minute ventilation, resulting in a state of chronic, compensated respiratory alkalosis (mildly alkaline pH, low PaCO2, and low HCO3-).
PreviousPage 43 / 53Next
Obstetrics and Gynecology Practice Questions — USMLE Step 2 CK — Page 43 | Examkin