A 32-year-old multiparous woman undergoes emergency cesarean section at 38 weeks for placenta previa. Delivery is uncomplicated, but at 2 hours postoperatively, the patient develops sudden, profuse vaginal bleeding. Vital signs: BP 88/54 mmHg, HR 128/min, RR 24/min, O~2~ saturation 94% on room air. Hemoglobin is 7.1 g/dL (pre-operative: 10.2 g/dL). Uterine examination reveals a firm, well-contracted uterus. Speculum examination shows heavy bleeding from the cervix and lower uterine segment. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis This patient has **cervical and lower uterine segment lacerations** — a critical cause of postpartum hemorrhage that is often overlooked because the uterus is firm and well-contracted. ### Key Diagnostic Clues ```mermaid flowchart TD A[Postpartum Hemorrhage]:::outcome --> B{Uterine tone?}:::decision B -->|Soft/boggy| C[Uterine Atony]:::outcome B -->|Firm/contracted| D[Bleeding source below uterus]:::outcome D --> E{Speculum exam findings?}:::decision E -->|Bleeding from cervix/lower segment| F[Cervical/Lower Uterine Lacerations]:::action E -->|No visible bleeding| G[Coagulopathy or Uterine Rupture]:::urgent F --> H[Repair lacerations under anesthesia]:::action ``` **High-Yield:** A firm, well-contracted uterus with ongoing hemorrhage points to a **structural cause** — lacerations, not atony. **Key Point:** Cervical lacerations account for 5–10% of PPH and are the most common cause of hemorrhage when the uterus is contracted. They are particularly common after: - Operative deliveries (forceps, vacuum, cesarean) - Rapid labor with large fetal head - Placenta previa (as in this case — abnormal placentation increases risk of trauma) ## Why Cervical/Lower Uterine Lacerations? 1. **Firm uterus on palpation** — excludes uterine atony 2. **Speculum examination shows bleeding from cervix and lower uterine segment** — direct visualization of the source 3. **Cesarean delivery** — surgical manipulation increases risk of cervical trauma 4. **Placenta previa** — abnormal placentation and increased vascularity increase bleeding risk 5. **Hemodynamic instability** (BP 88/54, HR 128) — indicates significant ongoing blood loss ## Management of Cervical Lacerations | Step | Action | Details | |------|--------|----------| | 1 | Assess severity | Grade 1–4 (superficial to full-thickness with extension into lower segment) | | 2 | Anesthesia | Spinal or epidural (if already in place) or general | | 3 | Visualization | Speculum + good lighting; may need cervical retraction | | 4 | Repair | 2-0 or 3-0 absorbable suture (chromic catgut or polyglactin), interrupted or running stitch | | 5 | Hemostasis | Ensure bleeding stops; may require vaginal packing if extensive | | 6 | Supportive care | IV fluids, blood transfusion, antibiotics | **Clinical Pearl:** Always perform a systematic inspection of the cervix and lower uterine segment after any delivery (vaginal or cesarean) if there is postpartum hemorrhage, even if the uterus is firm. ## Why Uterine Atony Is Incorrect - The uterus is **firm and well-contracted** — atony is excluded by definition - Atony presents with a soft, boggy, enlarged uterus ## Why Uterine Rupture Is Incorrect - Uterine rupture typically presents with: - Severe abdominal pain (not mentioned) - Intra-abdominal hemorrhage with peritoneal signs - Fetal parts palpable in the abdomen - Sudden cardiovascular collapse - The bleeding is localized to the vagina (speculum-visible), not intra-abdominal - Uterine rupture is rare after planned cesarean section ## Why Coagulopathy Is Incorrect - Coagulopathy develops **secondary** to massive transfusion (>4–6 units RBC), not as a primary diagnosis - The patient has received minimal transfusion at 2 hours postoperatively - Coagulopathy would present with oozing from multiple sites (incision, IV sites, mucous membranes), not localized vaginal bleeding - PT, aPTT, fibrinogen, and platelet count would be abnormal [cite:Williams Obstetrics 26e Ch 41; ACOG Practice Bulletin #183]