Review Question - QID 216571

This patient with a history of gestational hypertension, sudden onset painful vaginal bleeding, oozing around IV sites, and signs of fetal distress (sinusoidal pattern on fetal heart rate) likely has placental abruption, which can be complicated by disseminated intravascular coagulation (DIC). Fibrinogen levels decline rapidly in DIC due to excessive activation of the coagulation cascade leading to cleavage of fibrinogen to fibrin.

Placental abruption is characterized by detachment of the placenta from the uterine wall prior to delivery after 20 weeks of gestation. Clinically, placental abruption presents with sudden onset vaginal bleeding, abdominal pain, and uterine contractions. The proximate pathophysiology of placental abruption is the rupture of maternal vessels in the decidua basalis which causes the accumulation of blood that dissects the decidua and placenta. In addition, thrombin generation increases in placental abruption due to the direct and indirect release of tissue factor from the decidua. In turn, the overwhelming production of thrombin can lead to systemic activation of coagulation, conversion of fibrinogen to fibrin, formation of microvascular thrombi, depletion of platelets and clotting factors, and excessive bleeding (i.e., DIC). Management includes the administration of intravenous fluids and supplemental oxygen, continuous maternal and fetal monitoring, and prompt delivery in severe cases.

Schmidt et al. review the etiology, pathophysiology, clinical features, management, and complications of placental abruption. The authors note that in patients with coagulopathy, vaginal birth may present less risk to the mother. However, if there are signs of fetal distress, the authors still recommend emergency cesarean birth to protect the fetus.

Incorrect Answers:
Answer 1: A bruised and tender cervix would be found in cervical trauma, which is typically caused by sexual intercourse. Cervical trauma also presents as sudden onset vaginal bleeding with mild to moderate pelvic pain. However, it would not be expected to present with active bleeding from the cervical os or signs of fetal distress.

Answer 3: A placenta covering the cervical os defines placenta previa, a cause of painless vaginal bleeding prior to the rupture of membranes. Placenta previa can cause bright red vaginal bleeding but usually does not cause fetal distress.

Answer 4: Uterine rupture can cause sudden onset vaginal bleeding, severe abdominal pain, hemodynamic instability, and fetal distress. However, uterine rupture usually leads to a pause in contractions and occurs during active labor. An important risk factor for uterine rupture is previous cesarean delivery.

Answer 5: Velamentous cord insertion is characterized by umbilical vessels unprotected by Wharton jelly at the site of placental insertion. Velamentous cord insertion can cause painless, sudden-onset vaginal bleeding after the rupture of membranes. It is a risk factor for vasa previa (fetal vessels within 2 cm of the internal cervical os), which can also cause painless, sudden onset vaginal bleeding.

Bullet Summary:
Placental abruption presents as painful, sudden onset vaginal bleeding in the third trimester and can be complicated by disseminated intravascular coagulation.