Obstetrics and Gynecology

A healthy $28$-year-old woman presents to the outpatient clinic at $9$ weeks gestation for initial obstetric care. Her obstetric history includes an uncomplicated spontaneous vaginal delivery three years ago. She currently complains of mild fatigue and morning nausea but denies palpitations, heat intolerance, or weight loss. Vital signs are normal. The thyroid gland is not enlarged on palpation. Screening laboratory tests return the following results:

Which of the following pairs of maternal adaptations best explains this patient's thyroid panel?

A 31-year-old woman, gravida 2, para 1, is evaluated in the labor ward at 40 weeks gestation. She is currently in the active phase of the first stage of labor. Uterine contractions are occurring every 3 minutes. The continuous electronic fetal heart rate tracing demonstrates a baseline of 135/min with moderate variability. Following each of the last four contractions, the fetal heart rate gradually decreases to a nadir of 115/min and then returns to the baseline roughly 20 seconds after the contraction has finished. Which of the following is the most appropriate initial step in the management of this patient?

A $29$-year-old multiparous woman at $40$ weeks gestation is currently on the labor ward receiving an oxytocin infusion to augment active labor. Her pregnancy history includes $1$ prior uncomplicated vaginal delivery. Vital signs are within normal limits. The continuous electronic fetal monitor displays a baseline heart rate of $145$/min with minimal variability. Upon review of the tracing, the physician notes recurrent, smooth, gradual decreases in the fetal heart rate. The lowest point of each deceleration consistently occurs after the peak of the corresponding uterine contraction, and the heart rate returns to baseline after the contraction has finished. Cervical examination reveals $6$ cm dilation and $80\%$ effacement with the fetal vertex at $0$ station. Which of the following is the most appropriate next step in management?

Match each clinical presentation of a pregnant patient in the third trimester with the pathophysiologic description of the most likely underlying obstetric complication.

A 29-year-old primigravida at 41 weeks gestation is admitted to the labor and delivery unit for induction of labor due to postterm pregnancy. She is currently receiving a continuous intravenous oxytocin infusion. Her vital signs are temperature 37.0°C (98.6°F), blood pressure 122/78 mmHg, and heart rate 88/min. Cervical examination reveals 7 cm dilation, 100% effacement, and the fetal vertex is at 0 station. Uterine contractions are occurring every 3 minutes and palpate firm. The continuous fetal heart rate monitor shows a baseline of 140/min with minimal variability. There are gradual, symmetric decreases in the fetal heart rate that reach their nadir after the peak of the uterine contractions and return to baseline after the contractions end. These decelerations occur with more than 50% of the contractions. Which of the following is the most appropriate next step in management?

Match each clinical and sonographic presentation of third-trimester complications with the most appropriate obstetric etiology.

A 32-year-old G2P1 at 39 weeks of gestation is in the second stage of labor. Following a 2-hour active pushing phase, the fetal head delivers but immediately retracts firmly against the maternal perineum. The anterior shoulder does not deliver with gentle downward traction. The obstetrician diagnoses shoulder dystocia and instructs the patient to stop pushing while requesting immediate assistance from anesthesia, pediatrics, and additional nursing staff.

Arrange the following obstetric interventions in the most appropriate sequential order of implementation, proceeding from initial first-line management to maneuvers of last resort.

A 29-year-old woman, gravida 2, para 1, is evaluated on the labor and delivery unit at 41 weeks gestation during an induction of labor for a postterm pregnancy. She is currently receiving continuous intravenous oxytocin. The most recent cervical examination demonstrates 5 cm dilation, 100% effacement, and -1 station. Uterine contractions are occurring every 3 minutes. Continuous fetal monitoring reveals a baseline heart rate of 135/min with minimal variability. Over the preceding 40 minutes, the fetal heart rate tracing demonstrates recurrent, gradual decreases in heart rate that initiate after the peak of each contraction, with the nadir occurring after the contraction has ceased. These heart rate decreases are present with more than half of the contractions. In response, the patient is repositioned to the left lateral decubitus position and administered an intravenous fluid bolus; however, the fetal monitor tracing remains unchanged following these interventions. Maternal vital signs are within normal limits. Which of the following is the most appropriate next step in management?

A 27-year-old woman, gravida 1, para 1, experiences a sudden onset of severe vaginal bleeding immediately following the delivery of the placenta. Her blood pressure drops to 80/40 mmHg and heart rate increases to 125/min. On pelvic examination, a purplish, fleshy mass is seen protruding through the vaginal introitus, and the uterine fundus cannot be palpated through the anterior abdominal wall. Arrange the following management steps for this complication in the correct chronological sequence.

During routine prenatal care, physicians must be able to accurately differentiate normal physiological adaptations of pregnancy from pathological states. Match each normal maternal physiological or anatomical alteration (left) with its primary underlying mechanism or evolutionary rationale (right).

A 24-year-old primigravida at 39 weeks gestation is completely dilated and actively pushing in the second stage of labor. The fetal head is descending through the maternal pelvis. To successfully navigate the pelvic structures, the fetus must undergo a series of specific positional changes. Arrange the following cardinal movements of labor in the correct chronological order from first to last.

During a preconception counseling session, a healthy nulliparous patient inquires about the timeline of physiological changes she should expect during a normal pregnancy. Arrange the following maternal physiological and anatomical milestones in the chronological order in which they typically reach their peak, nadir, or maximum extent during a normal, uncomplicated gestation.

Following a spontaneous vaginal delivery of a macrosomic infant, a patient develops profuse vaginal bleeding. The placenta was delivered intact five minutes prior. Abdominal examination reveals a soft, boggy fundus resting at the level of the umbilicus. The care team identifies uterine atony and initiates a management protocol. Assuming the hemorrhage persists despite each successive action, arrange the following interventions in the standard chronological order of escalation.

A pregnant individual in her fourth pregnancy (gravida 4, para 1) is evaluated in the labor suite at 40 weeks and 1 day of gestation. She is currently undergoing a trial of labor after a previous cesarean delivery. Her obstetric history is notable for a primary low transverse surgical delivery three years ago due to a breech presentation. Her prenatal course for the current pregnancy has been uncomplicated. Over the last four hours, her labor has progressed steadily. Her most recent cervical examination revealed $8$ cm of dilation and a fetal station of $+1$. Her contractions have been strong, occurring every 2 to 3 minutes.

Shortly after the examination, the patient suddenly screams in agony, reporting an intense, tearing pain in her lower abdomen that does not resolve between contractions. Concurrently, the intrauterine pressure monitor shows an abrupt cessation of regular uterine contractions, and the continuous fetal heart rate tracing reveals a precipitous drop to a baseline of 75/min for the last four minutes. A rapid bedside physical examination shows moderate vaginal bleeding, and the fetal presenting part is now palpable at the $-2$ station.

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

Match each distinct clinical or laboratory presentation during a normal pregnancy to the primary physiological mechanism responsible for that specific adaptation.

An obstetrician is called to evaluate a $27$-year-old primigravida at $36$ weeks gestation in the labor and delivery unit due to acute respiratory difficulty. She was admitted four hours ago for preeclampsia with severe features, presenting with a blood pressure of $170/110\text{ mmHg}$, new-onset visual scotomata, and proteinuria. An intravenous magnesium sulfate infusion was initiated for seizure prophylaxis. Over the last $30$ minutes, she has developed significant difficulty swallowing, blurred vision, bilateral ptosis, and profound generalized muscle weakness. Her temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $150/95\text{ mmHg}$, heart rate is $92/\text{min}$, and respiratory rate is $10/\text{min}$ with shallow efforts. Pulse oximetry is $91\%$ on room air. Physical examination reveals weak neck flexion. Patellar reflexes are $2+$ bilaterally. Urine output over the last $4$ hours has been $220\text{ mL}$. Continuous fetal heart rate monitoring demonstrates a baseline of $140/\text{min}$ with moderate variability and no decelerations.

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

A $32$-year-old woman, gravida $3$, para $2$, at $34$ weeks gestation comes to the clinic for a routine evaluation. She reports feeling more fatigued over the past two weeks, along with mild shortness of breath when climbing the stairs at her home. She occasionally notices her heart beating faster than usual. She reports good fetal movement and denies chest pain, cough, or orthopnea. Her past medical history is unremarkable. Blood pressure is $110/64$ mm Hg, pulse is $104$/min, and respirations are $18$/min. Pulse oximetry shows $98\%$ on room air. Physical examination reveals clear lungs bilaterally. Cardiac auscultation shows a grade $2/6$ systolic ejection murmur best heard at the left sternal border without radiation. Trace bilateral pitting edema is present at the ankles.

Laboratory and diagnostic studies show the following:
Hemoglobin: $11.2$ g/dL
Hematocrit: $33\%$
Platelet count: $185,000/\text{mm}^3$
Serum creatinine: $0.5$ mg/dL

Arterial blood gas (room air):
pH: $7.45$
$\text{PaCO}_2$: $29$ mm Hg
$\text{PaO}_2$: $102$ mm Hg
$\text{HCO}_3^-$: $20$ mEq/L

An electrocardiogram demonstrates normal sinus rhythm with left axis deviation.

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

An 18-year-old nulliparous patient at 38 weeks gestation is evaluated on the labor and delivery unit. She was admitted in active labor, and artificial rupture of membranes was performed two hours ago. Her temperature is 37.0°C (98.6°F) and blood pressure is 110/70 mmHg. Cervical examination shows 7 cm dilation, 100% effacement, and the fetal vertex at +1 station. The external fetal monitor shows a baseline heart rate of 145/min with moderate variability. During the monitoring period, the fetal heart rate frequently exhibits abrupt decreases to 85/min. These decreases reach their nadir within 15 seconds of onset, last for roughly 45 seconds, and rapidly return to the baseline of 145/min. These episodes occur during the majority of her uterine contractions. Which of the following is the most appropriate initial step in management?

A 29-year-old multiparous patient at 39 weeks gestation is admitted to the labor and delivery unit in active labor. Her cervix is 5 cm dilated and 100% effaced, with the fetal vertex at -2 station. Thirty minutes later, she experiences a spontaneous gush of clear vaginal fluid. Immediately following this event, the electronic fetal monitor demonstrates a sudden, prolonged drop in the fetal heart rate to 70/min lasting for over 3 minutes. A sterile vaginal examination reveals a palpable, pulsating rope-like mass in the vaginal canal ahead of the fetal presenting part. Which of the following is the most appropriate immediate step in management?

Match each clinical presentation of postpartum hemorrhage with its most likely underlying obstetric etiology.