Uterine Rupture
A 40-year-old woman, gravida 4 para 2, at 41 weeks is 6 hours into induction with vaginal prostaglandin. She develops sudden severe abdominal pain, contractions cease, and heavy vaginal bleeding occurs. Blood pressure is 78/40 mm Hg, pulse 132 beats/min, the presenting part has receded, and fetal heart tones are absent. Which of the following is the most likely diagnosis?
- A.Placenta previa
- B.Placental abruption
- C.Prostaglandin hypersensitivity reaction
- D.Uterine ruptureCorrect
Explanation
The combination of prostaglandin induction, sudden severe pain, cessation of contractions, loss of fetal station, vaginal bleeding, shock and absent fetal heart tones is uterine rupture. Prostaglandins induce strong sustained contractions and can cause tachysystole, and in a multiparous post-term uterus that is already thinned and overstretched the myometrium gives way. Risk factors present here are grand multiparity, post-term pregnancy and uterotonic induction; a previous caesarean scar is the commonest risk factor overall but rupture also occurs in unscarred uteri, particularly with injudicious oxytocic use. Recession of the presenting part is a near-specific sign, because the fetus has extruded partly or completely into the peritoneal cavity, and abdominal palpation may reveal easily felt fetal parts alongside a separate contracted uterus. Fetal heart rate abnormality is the earliest and most sensitive sign in most series, progressing to prolonged bradycardia then loss of tones. Management is immediate laparotomy with resuscitation running in parallel, massive transfusion activation, delivery, and repair or hysterectomy depending on the tear. Placenta praevia bleeds painlessly and does not cause pain with loss of station, and abruption gives a tense tender uterus with continuing contractions rather than their cessation. Prostaglandin hypersensitivity is not a recognised cause of intrapartum haemorrhagic shock.
Why each option
- A.
- Praevia produces painless bleeding without abdominal pain, shock out of proportion, or recession of the presenting part.
- B.
- Abruption gives a woody, tender uterus with continuing or increased tone rather than sudden cessation of contractions and loss of station.
- C.
- Prostaglandins can cause tachysystole, fever, vomiting or diarrhoea, but they do not cause haemorrhagic shock with a receding presenting part.
- D.
- Correct. Sudden pain, stopped contractions, bleeding, shock, receding presenting part and absent fetal heart tones after prostaglandin induction define uterine rupture.
Reference: Williams Obstetrics, 26th ed., 2022, chapter on Uterine Rupture
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