Snapshot A 30-year-old G1P0 woman at 36 weeks of gestation presents to the emergency room with sudden onset of moderate back pain and strong uterine cramping that began 2 hours ago. Thirty minutes prior to the onset of back pain, she noted bright red vaginal bleeding. She has had no prenatal care. On physical exam she is afebrile; her blood pressure is 130/80 mmHg, pulse is 109/min, and respirations are 18/min. Abdominal palpation reveals a gravid, hypertonic uterus and palpable uterine contractions. You observe blood in the vaginal vault. Results of transabdominal ultrasound demonstrate retroplacental hemorrhage. Introduction Overview partial or complete placental detachment prior to delivery of the fetus diagnosis typically only applies to pregnancies > 20 weeks of gestation placenta abruptio and placenta previa are the 2 most common causes of third trimester bleeding Epidemiology incidence ~1% of all pregnancies 2/3 of cases are "severe" based on maternal, fetal, and neonatal morbidity demographics more common in African-American women risk factors prior placental abruption trauma (e.g., motor vehicle accident) maternal smoking cocaine use hypertensive disorders eclampsia preeclampsia chronic hypertension premature rupture of membranes uterine structural abnormalities bicornate uterus uterine synechiae leiomyoma abnormalities of maternal serum biochemical markers increased alpha fetoprotein increased hCG very low or very high levels of inhibin A hyperhomocystinemia Pathophysiology rupture of maternal vessels in the decidua basalis bleeding into the decidual-placental interface causes placental separation from the uterine wall Prognosis mother increased morbidity and mortality prompt intervention decreases the incidence of maternal mortality increased long-term risk of premature cardiovascular disease 2x risk of death after coronary artery revascularization in the future may reflect underlying maternal vascular abnormalities that manifest as abruption during pregnancy fetus increased morbidity and mortality especially when preterm Presentation Symptoms abrupt third trimester bleeding abdominal and/or back pain uterine contractions Physical exam vital signs consistent with bleeding if severe hypotension tachycardia gravid hypertonic uterus uterine tenderness blood/clots may be observed in the vaginal vault fetal distress nonreassuring fetal heart rate pattern Imaging Ultrasound indications diagnosis of retroplacental hematoma classic for placental abruption usually present if abruption is more severe may be absent in milder cases of abruption used to rule out placenta previa Studies Serum fibrinogen has the best correlation with severity of bleeding, presence of DIC, and need for blood products ≤ 200 mg/dL predicts severe postpartum hemorrhage Pathologic placental evaluation supports the clinical diagnosis Differential Placenta previa key distinguishing feature presents as painless vaginal bleeding Uterine rupture also associated with trauma may also have sudden onset symptoms vaginal bleeding abdominal pain fetal heart rate abnormalities maternal hypotension and tachycardia key distinguishing features loss of uterine tone/contractions occurs after onset of labor other risk factors previous C-section Normal or pre-term labor key distinguishing feature has more gradual onset of signs/symptoms Treatment Medical expectant management with continuous fetal monitoring indications when both the mother and fetus are stable and the fetus is < 34 weeks gestation fluid replacement indications all patients with signs of bleeding modalities placement of 1-2 large-bore intravenous lines administer lactated ringers (LR) to maintain urine output > 30 mL/hr serum studies indications all patients with suspected plantental abruption modalities complete blood count (CBC) blood type and screen with crossmatch if transfusion is likely coagulation studies liver chemistries in patients with suspected preeclampsia or HELLP syndrome RhoGAM indications all Rh(D)-negative mothers with vaginal bleeding if father is Rh(D)-positive or unknown modalities single intramuscular or intravenous dose vaginal delivery indications fetus is ≥ 36 weeks gestation no other indications for cesarean delivery if the patient is not in active labor amniotomy and oxytocin administration administer standard delivery medications group B streptococcus prophylaxis according to guidelines magnesium sulfate for neuroprotection if < 32 weeks of gestation Surgical immediate delivery with cesarean delivery indications non-reassuring fetal status hemodynamic instability in the mother if fetus is 34-36 weeks gestation due to risk of progressive placental separation and maternal/fetal compromise Complications Disseminated intravascular coagulation (DIC) when placental separation > 50% Hemorrhagic shock Maternal death Recurrence risk in future pregnancies 3-15% have a recurrence Fetal anemia Fetal death when placental separation >50%