Examkin

Question

Difficulty: HardObstetric Complications

Match each characteristic clinical presentation of a third-trimester or intrapartum obstetric emergency with its most likely underlying etiology.

  • Presents with sudden-onset abdominal or back pain, a rigid and tender uterus on palpation, high-frequency contractions, and a fetal heart rate tracing frequently demonstrating late decelerations.Placental abruption (Abruptio placentae)
  • Occurs during active labor, characterized by acute sharp suprapubic pain, sudden cessation of previously regular uterine activity, recession of the presenting fetal part, and maternal hemodynamic instability.Uterine rupture
  • Characterized by painless vaginal bleeding occurring immediately upon artificial or spontaneous amniotomy, followed rapidly by a sinusoidal fetal heart rhythm or profound fetal bradycardia.Vasa previa
  • Manifests as sudden, painless, profuse bright red vaginal bleeding in the third trimester without associated uterine tenderness; the fetal heart rate typically remains reassuring during the initial presentation.Placenta previa

Answer

The correct matching aligns placental abruption with a painful, rigid uterus; uterine rupture with loss of fetal station and cessation of contractions; vasa previa with bleeding immediately following membrane rupture accompanied by fetal bradycardia; and placenta previa with painless bleeding and a soft uterus.
Each obstetric emergency has a highly specific clinical signature. Placental abruption is defined by pain and a hypertonic uterus. Uterine rupture is defined by mechanical failure (loss of station, halted contractions). Vasa previa is defined by the temporal relationship to amniotomy and immediate fetal deterioration. Placenta previa is defined by painless bleeding with reassuring initial fetal status.

Step-by-Step Solution

1
Evaluate the presence or absence of abdominal pain and uterine tone.
Pain and hypertonus indicate placental abruption or uterine rupture, whereas painless bleeding suggests placenta previa or vasa previa.
Uterine distention and myometrial irritation from retroplacental hemorrhage cause pain, whereas cervical dilation stretching maternal vessels in previa is typically painless.
2
Assess the exact timing of the bleeding relative to membrane rupture and analyze the fetal heart rate.
Bleeding immediately upon amniotomy with acute fetal bradycardia or a sinusoidal pattern isolates vasa previa.
In vasa previa, the ruptured vessels are fetal in origin, leading to immediate fetal exsanguination and catastrophic heart rate changes.
3
Identify signs of catastrophic mechanical failure during labor.
The sudden loss of uterine tone and recession of the fetal presenting part isolates uterine rupture.
When the myometrium tears completely, the intrauterine pressure drops instantly, stopping effective contractions and allowing the fetus to slip back into the abdominal cavity.

Key Concept

Differentiating etiologies of third-trimester and intrapartum bleeding based on clinical hallmarks: pain, uterine tone, timing of membrane rupture, and fetal heart rate patterns.
Rate this question

Topics

Obstetric Complications

More questions from this topic