Placental Abruption
Obstetrics & Gynecology
Illness script · Obstetrics & Gynecology
Placental Abruption
Premature separation of a normally implanted placenta from the uterine wall before delivery, causing hemorrhage and fetal compromise.
This illness script for Placental Abruption covers predisposing factors, classic presentation, mechanism, workup, management, and the clinical pivots that separate it from look-alikes—written for USMLE Step 1 and clerkship reasoning.
01
Predisposing factors
- Hypertension (chronic or preeclampsia) — #1 risk factor
- Trauma (MVA, domestic violence) — leading cause in young patients
- Prior abruption — 10–15× recurrence risk
- Cocaine/tobacco use (vasoconstriction)
- Preterm premature rupture of membranes (PPROM)
- Multiparity, advanced maternal age, thrombophilias
02
Presentation
- Sudden-onset painful dark vaginal bleeding (classic revealed type)
- Uterine hypertonicity / board-like rigidity — key exam finding
- Non-reassuring fetal heart tracing (late decels, bradycardia)
- May be painless if concealed; clinical severity underestimated by external blood loss
- Maternal hemodynamic instability disproportionate to visible bleeding
- DIC signs: oozing from IV sites, petechiae in severe cases
03
Pathophysiology
- Rupture of maternal decidual spiral arterioles → retroplacental hematoma
- Hematoma expands → progressive placental separation → fetal hypoxia
- Consumptive coagulopathy (DIC) from thromboplastin release into maternal circulation
- Concealed vs. revealed bleeding: hemorrhage may not externalize despite massive internal loss
04
Diagnostics
- Clinical diagnosis — do NOT delay delivery for imaging
- Ultrasound: retroplacental clot (only ~50% sensitive; negative does not rule out)
- CBC, fibrinogen, PT/PTT, type & crossmatch — fibrinogen <200 mg/dL signals severe DIC
- Continuous fetal monitoring mandatory
- Kleihauer-Betke test in Rh-negative mothers to quantify fetal-maternal hemorrhage
05
Management
- Immediate IV access ×2, aggressive fluid/blood resuscitation
- Emergent cesarean delivery for non-reassuring fetal status or hemodynamic instability
- Vaginal delivery acceptable if fetus is remote/previable, stable maternal status, and reassuring FHR
- Correct coagulopathy: FFP, cryoprecipitate (fibrinogen target >200), platelets
- RhoGAM for Rh-negative mothers; ICU-level monitoring for DIC
06
Clinical pivots
How to separate this script from the look-alikes that show up on exams and on the wards.
Placenta previa
Previa: painless bright-red bleeding, placenta overlying os on ultrasound; abruption: painful, dark blood, hyperTonic uterus
Uterine rupture
Rupture: fetal parts palpable abdominally, sudden loss of fetal station, scar from prior cesarean; abruption: intact uterine wall
Vasa previa
Vasa previa: fetal (not maternal) blood loss confirmed by Apt test, occurs at membrane rupture, no maternal instability initially
Preterm labor
PTL: regular contractions without board-like rigidity, no significant bleeding, fetal status typically reassuring initially
Keep reading
Full library- Pelvic Inflammatory DiseaseAscending polymicrobial infection of the upper female genital tract (uterus, tubes, ovaries), most often sexually transmitted.
- Preeclampsia with Severe FeaturesHypertensive disorder of pregnancy ≥20 weeks with end-organ damage (BP ≥160/110, proteinuria ± severe features).
Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.