A 32-year-old primigravida at 36 weeks of gestation presents with abdominal pain and vaginal bleeding. On examination, the uterus is tense and tender. Fetal heart rate is 140 bpm. On abdominal palpation, the head is felt in the fundus and buttocks are in the lower segment. What is the investigation of choice to confirm the presentation and assess fetal well-being?

Explanation

## Investigation of Choice for Suspected Breech Presentation with Complications ### Clinical Context The clinical findings — head in fundus, buttocks in lower segment, vaginal bleeding, and uterine tenderness — are consistent with breech presentation, possibly complicated by placental abruption. Confirmation and assessment of fetal viability are urgent priorities. ### Why Transabdominal Ultrasound with Doppler is Correct **Key Point:** Ultrasound is the gold standard for confirming fetal presentation, assessing placental location, detecting abruption, and evaluating fetal well-being (heart rate, movement, amniotic fluid volume) in a single non-invasive study. **High-Yield:** In breech presentation at term, ultrasound: - Confirms presentation type (frank, complete, footling) - Measures estimated fetal weight (important for counseling on vaginal vs. cesarean delivery) - Assesses for congenital anomalies (associated with breech in ~10% of cases) - Detects placental abruption (evidenced by retroplacental clot or heterogeneous echotexture) - Evaluates umbilical artery Doppler to assess fetal perfusion if abruption suspected **Clinical Pearl:** In the presence of vaginal bleeding and uterine tenderness at 36 weeks with breech presentation, ultrasound is essential to rule out placental abruption, which is a contraindication to vaginal breech delivery and mandates urgent cesarean section. ### Why Other Options Are Suboptimal | Investigation | Limitation | | --- | --- | | Pelvic X-ray | Exposes fetus to ionizing radiation; does not assess soft tissue (placenta, abruption) or fetal well-being; rarely used in modern obstetrics for presentation confirmation | | Vaginal examination under anesthesia | Invasive; risks further bleeding if placenta previa or abruption present; does not assess fetal viability or placental status; reserved for specific indications (e.g., assessment of pelvic adequacy in selected breech cases) | | Cardiotocography alone | Assesses fetal heart rate and uterine contractions but does NOT confirm presentation or detect abruption; must be combined with imaging | **Warning:** Vaginal examination in suspected placental abruption with vaginal bleeding can precipitate massive hemorrhage and is contraindicated until imaging excludes previa/abruption.