A 28-year-old woman, gravida 2 para 1, at 37 weeks gestation comes to the hospital due to severe abdominal and back pain. The patient's prenatal course has been uncomplicated, and her only medication is a daily prenatal vitamin. She had a prior cesarean delivery and is scheduled for a repeat cesarean delivery at 39 weeks gestation. Blood pressure is 90/60 mm Hg and pulse is 130/min. Fetal heart rate tracing is shown in the exhibit. Physical examination shows a palpable, irregular protuberance in the lower abdomen and moderate vaginal bleeding. Which of the following is the most likely cause of this patient's presentation?

Question

A 28-year-old woman, gravida 2 para 1, at 37 weeks gestation comes to the hospital due to severe abdominal and back pain.  The patient's prenatal course has been uncomplicated, and her only medication is a daily prenatal vitamin.  She had a prior cesarean delivery and is scheduled for a repeat cesarean delivery at 39 weeks gestation.  Blood pressure is 90/60 mm Hg and pulse is 130/min.  Fetal heart rate tracing is shown in the exhibit.  Physical examination shows a palpable, irregular protuberance in the lower abdomen and moderate vaginal bleeding.  Which of the following is the most likely cause of this patient's presentation?

Quizplus · Accepted Answer

11ec25c8_da14_8f77_bc81_a1b88351a2dc_MD0003_00 This patient most likely has uterine rupture, a life-threatening obstetric emergency caused by complete uterine wall disruption. The most common risk factor is prior uterine surgery (eg, cesarean delivery), which leaves a weakened, inelastic myometrial scar that is prone to tear with uterine distension or labor contractions. uterine wall disruption When the uterine myometrium ruptures, patients develop a sudden onset of abdominal pain. Because the pregnant uterus is highly vascular, bleeding can quickly lead to intraabdominal hemorrhage (eg, diffuse back pain), vaginal bleeding, and shock (eg, hypotension, tachycardia), as in this patient. Uterine rupture may also cause fetal parts to partially expulse into the maternal abdomen, resulting in a palpable, irregular protuberance in the lower abdomen. Patients with uterine rupture may have changes in contraction pattern and uterine tone (eg, increased or decreased); however, continued contractions (as in this patient) are not uncommon. An abnormal fetal heart rate tracing is often the first sign of uterine rupture and can present as bradycardia, late decelerations, or variable decelerations. In this patient, prolonged late decelerations are the result of disrupted uteroplacental flow. Due to the high risk of maternal and fetal morbidity, management of uterine rupture is with emergency laparotomy and cesarean delivery. (Choice A) Abruptio placentae (ie, premature separation of the placenta from the uterus) may present with abdominal pain, vaginal bleeding, and an abnormal fetal heart rate tracing; however, it is not associated with an irregular abdominal protuberance (ie, abdominally palpable fetal parts). Abruptio placentae (Choice B) Although normal labor with uterine fibroids may present with an abdominal protuberance (ie, palpable fibroid), it is not associated with hemorrhagic shock or an abnormal fetal heart rate tracing. (Choice C) Patients with prior cesarean delivery, such as this patient, are at increased risk of placenta previa, which can cause vaginal bleeding with contractions. However, bleeding with this condition is painless and not associated with an abdominal protuberance. placenta previa (Choice D) Umbilical cord prolapse can cause an abnormal fetal heart rate tracing (eg, recurrent variable decelerations) due to acute cord compression; however, it does not cause severe abdominal pain. Umbilical cord prolapse Educational objective: Uterine rupture typically presents with severe abdominal pain, intraabdominal and/or vaginal bleeding, and an abnormal fetal heart rate tracing (eg, late decelerations). Abdominal examination may show palpable fetal parts (eg, an irregular protuberance). References: Risk factors for uterine rupture and neonatal consequences of uterine rupture: a population-based study of successive pregnancies in Sweden. (http://www.ncbi.nlm.nih.gov/pubmed/17877673) ACOG practice bulletin no. 205: vaginal birth after cesarean delivery. (http://www.ncbi.nlm.nih.gov/pubmed/30681543)

A 28-Year-Old Woman, Gravida 2 Para 1, at 37 Weeks