Uterine wall rupture in a primigravid patient with oligohydramnios as the first manifestation: A case report

RATIONALE: Spontaneous uterine rupture during pregnancy, occurring most often during labor in the context of a scarred uterus, is a serious obstetric complication. Perhaps even more serious because of its extreme rarity, spontaneous uterine rupture in a primigravid patient with an unscarred gravid uterus would be essentially unexpected. Clinical manifestations of unscarred uterine ruptures are nonspecific and can be confusing, making a correct early diagnosis very difficult. PATIENT CONCERNS: A primigravid woman at 27 weeks of gestation presented to our hospital with acute oligohydramnios. Ultrasound examination at her local hospital revealed oligohydramnios that had not been present 1 week previously. A specific cause of the acute oligohydramnios, however, was not established. DIAGNOSIS: Upon transfer to our hospital, the patient was hemodynamically stable without abdominal tenderness or peritoneal signs. Transabdominal ultrasound was repeated and confirmed oligohydramnios and seroperitoneum. The fetal heart rate was in the normal range, and blood tests revealed a low hemoglobin level of 91 g/L, which had been normal recently. A repeat sonogram after admission found that there was almost no amniotic fluid within the uterine cavity, and there was increased peritoneal fluid. Repeat hemoglobin showed a further decrease to 84 g/L. The combination of increased free abdominal fluid, lack of intrauterine fluid, and acutely decreasing hemoglobin strongly suggested uterine rupture with active intraperitoneal bleeding. INTERVENTIONS: Emergent laparotomy was performed, and a male infant was delivered. Comprehensive abdominal exploration revealed a rupture in the right uterine cornua with ongoing slow bleeding, through which a portion of the amniotic sac protruded into the abdominal cavity. OUTCOMES: The laceration was repaired, the patient and neonate recovered without complications, and were discharged 5 days postoperatively. LESSONS: An increased awareness of the rare but real possibility of spontaneous uterine rupture in a primigravid patient with no prior uterine scarring helped to establish an earlier diagnosis. Obstetricians should consider this possibility in pregnant females, even in the absence of risk factors and in early gestational age, when sudden unexplained clinical manifestations, such as acute oligohydramnios, are encountered.