A 36-year-old woman, gravida 1 para 0, at 38 weeks gestation is brought to the emergency department due to sudden vaginal bleeding and severe lower abdominal pain. The patient had a prenatal course notable for diet-controlled gestational diabetes mellitus. An ultrasound at 20 weeks gestation showed normal fetal anatomy and a fundal placenta. The patient has a 5-pack-year smoking history and has been trying to quit. Temperature is 37 C (98.6 F), blood pressure is 158/96 mm Hg, and pulse is 112/min. Physical examination shows uterine tenderness and moderate vaginal bleeding. Digital cervical examination shows cervical dilation at 3 cm with the fetus in vertex presentation at 0 station. Fetal heart tracing shows a heart rate of 140/min with accelerations and moderate variability. Contractions occur every 2 minutes and last for 20 seconds. Urinalysis shows 3+ protein. This patient is at greatest risk of developing which of the following complications?
Abruptio placentae | |
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This patient with severe abdominal pain and vaginal bleeding likely has abruptio placentae. Placental abruption is retroplacental bleeding that occurs between the placenta and uterine decidua that causes placental detachment and vaginal bleeding. The accumulation of blood in this space causes increased intrauterine pressure (eg, lower abdominal and/or back pain); a firm, tender uterus; and high-frequency contractions. Preeclampsia (eg, hypertension, proteinuria) and tobacco use are risk factors.
Some cases of abruptio placentae are self-limited and clinically insignificant; however, as more of the placenta detaches, there is greater risk for maternal and fetal complications. Maternal complications include hemorrhage, hypovolemic shock, and disseminated intravascular coagulation (due to tissue factor released in response to decidual bleeding). Potential fetal complications include impaired perfusion (eg, abnormalities on fetal heart rate tracing if hypoperfusion persists and hypoxia develops) and fetal demise.
(Choice B) A retained placenta occurs with placenta accreta, which typically presents with postpartum bleeding due to failed placental detachment after fetal delivery. Common risk factors are prior uterine surgery and an anterior placenta, which are not present in this patient.
(Choice C) Septic shock can occur in patients with an intraamniotic infection (IAI), which typically presents with uterine tenderness. However, patients with IAI typically have fever, fetal tachycardia, and malodorous vaginal discharge, none of which are seen in this patient.
(Choice D) Umbilical cord prolapse occurs when the umbilical cord delivers through the cervix ahead of the presenting fetal part. Risk factors include malpresentation (eg, breech) and an unengaged fetal presenting part (eg, severe polyhydramnios). In this patient, the fetal vertex is at 0 station (well engaged in the pelvis), making cord prolapse unlikely to occur.
(Choice E) Uterine rupture can cause acute abdominal pain and vaginal bleeding. It typically occurs in laboring patients with prior uterine surgery (eg, cesarean delivery), uterine overdistension (eg, twin gestation), or tetanic contractions (eg, oxytocin use). It is unlikely to occur in this patient with no risk factors.
Educational objective:
Abruptio placentae is the premature separation of the placenta from the uterine decidua prior to fetal delivery. It typically presents with painful vaginal bleeding; a firm, tender uterus; and high-frequency contractions. Complications include maternal hemorrhage, hypovolemic shock, and disseminated intravascular coagulation.