Spontaneous uterine rupture of an unscarred uterus in the second trimester: A case report

Uterine rupture during pregnancy is a rare but life-threatening complication with incidence in an unscarred uterus of 0.7 per 10 000 deliveries.1 Sgayer et al. identified 84 cases of rupture in an unscarred uterus, with the majority occurring beyond 23 weeks gestation with at least one identifiable risk factor.2 We present a case of spontaneous rupture in an unscarred uterus at 17 weeks gestation with no identified risk factors. Consent for publication of the patient's clinical information and images was obtained. Ethics approval was waived in accordance with local legal frameworks. A 34-year-old woman, G2 P1, presented at 17 weeks gestation to the emergency department following syncope. Her pregnancy was spontaneously conceived and uncomplicated with regular prenatal care. She had a previous term spontaneous vaginal delivery. She had no prior abdominal or uterine surgery. Her past medical history was non-contributory. At presentation, she reported weakness and mild–moderate abdominal pain. A bedside scan revealed significant free fluid in the right upper quadrant and a live pregnancy, prompting administration of intravenous fluids, 2 g tranexamic acid and a unit of packed red blood cells (PRBC). Her blood pressure improved to 102/50 mmHg from 62/45 mmHg, although her tachycardia worsened from 95–103 to 120–130 bpm. The gynecology team was consulted urgently. She denied any light-headedness or vaginal bleeding. Her abdomen was tender at the uterine fundus, although non-peritonitic. Her hemoglobin remained stable, from 122 g/L to 118 g/L. Given her response to initial resuscitation, formal ultrasound was obtained, showing a large volume hemoperitoneum with partial extrauterine amniotic sac containing a live 17-week gestation, prompting urgent surgical management. A diagnostic laparoscopy revealed complete uterine rupture and an intra-abdominal amniotic sac. The pregnancy was deemed non-viable. A midline laparotomy was promptly performed, and 4 L of blood and large clots were evacuated. The amniotic sac and placenta were extruded from the uterine cavity (Figure 1). The uterus was contracted with rupture at the uterine fundus and right cornua. The tissue appeared dusky, in keeping with a local necrosis. The pregnancy was evacuated. The ruptured myometrium was cross-clamped and inspected. Necrosis was focal to the serosal and myometrial edges. A wedge resection of the necrotic tissue and right salpingectomy was performed. The remaining tissue was well vascularized, and the uterus was closed with separate closure of the endometrial cavity and layered closure of the myometrial defect. Intraoperatively, the patient required significant resuscitation, receiving 11 units of PRBC, four units of plasma, two units of platelets, 12 g fibrinogen, 11 L crystalloids, and 1 L albumin. Oxytocin and tranexamic acid were administered. Intravenous ceftriaxone and metronidazole were commenced, given the concern for local infection. Postoperatively, the patient was transferred to the intensive care unit intubated. She was extubated on postoperative day 0 (POD0) and transferred to the ward on POD1. She remained hemodynamically stable throughout her postoperative recovery. She was discharged in stable condition on POD5. Spontaneous rupture of an unscarred uterus is a rare but highly morbid complication. Most reported cases have at least one identifiable risk factor and occur late in pregnancy or during labour.1-3 Risk factors for rupture of an unscarred uterus include use of uterotonics, high parity, trauma, abnormal placentation, uterine anomalies, malpresentation, obstetric maneuvers, and history of curettage.2, 3 Additional possible risk factors include connective tissue disorders,4 adenomyosis at the rupture site,4 chronic systemic glucocorticosteroid use,5, 6 or assisted reproductive technologies.4, 5 Unlike most reported cases, this patient had no identifiable risk factors but presented with classic symptoms of uterine rupture, including abdominal pain and hypovolemic shock. Effective management requires prompt resuscitation and early surgical intervention.1 Fluid resuscitation and blood product administration are essential, while both obstetric and non-obstetric causes are considered. Differential diagnoses include placental abruption, uterine vessel rupture, ectopic pregnancy, ovarian cyst rupture, bleeding endometriosis, ruptured liver/spleen, and ruptured aneurysm.7 Immediate surgical exploration might be warranted without imaging in cases of unresponsive hemorrhagic shock. Surgical treatment for uterine rupture can include hysterectomy or repair of the rupture. Previous studies have reported uterine rupture repair with progression to live birth.8 In this case, the decision for uterine preservation was balanced against the risk of sepsis or postoperative bleeding. Immediate laparotomy is recommended in unstable patients. However, diagnostic laparoscopy can help assess the uterus and pregnancy to determine a plan of action.8 Key factors in surgical management include future fertility desires, extent of the rupture, hemodynamic instability, and surgical expertise. In subsequent pregnancies, the risk of recurrence of uterine rupture is approximately 4%–19%.2 However, this risk estimate is derived from patients with previous caesarean sections or myomectomy.2 Recurrence risk for patients without risk factors remains unknown and requires careful counseling. Although rare, spontaneous uterine rupture of an unscarred uterus can occur in early pregnancy without identifiable risk factors. Early surgical intervention and resuscitation are crucial for minimizing maternal morbidity and mortality. Surgical repair of the uterine rupture site can be an appropriate management plan for patients desiring fertility preservation for future pregnancies. Nour Bakhache, Erica Pascoal, and Carmen McCaffrey were involved in the initial draft of the case reports. All authors contributed to the final draft and reviewed it critically for content. All authors have provided approval for submission. The authors have no conflicts of interest to declare. Data sharing is not applicable to this article as no new data were created or analyzed in this study.