Spontaneous hemoperitoneum in pregnancy: Italian prospective population-based cohort study.

INTRODUCTION: Spontaneous hemoperitoneum in pregnancy is defined as a sudden non-traumatic intraperitoneal bleeding in pregnancy and up to 42 days postpartum. In the present study we aim to estimate the incidence and investigate the risk factors, the management and the outcomes of spontaneous hemoperitoneum in pregnancy in order to improve its clinical identification and reduce avoidable maternal deaths. MATERIAL AND METHODS: This is a prospective population-based cohort study, set in maternity units from nine Italian regions covering 75% of the national births. The study population comprises all women admitted for spontaneous intraperitoneal hemorrhage during pregnancy and up to 42 days postpartum between November 2017 and March 2020. Incident cases were reported by trained clinicians through electronic data collection forms. Descriptive statistics were performed. The main outcome measures included incidence rate of spontaneous hemoperitoneum in pregnancy, association with potential risk factors, clinical management and maternal and perinatal outcomes. RESULTS: Twenty-nine cases met the adopted definition of spontaneous hemoperitoneum in pregnancy with an estimated incidence rate of 0.04 per 1000 births. An increased risk ratio (RR) of this condition was observed in pregnancies conceived by assisted reproductive technology (RR = 6.60, 95% CI 2.52-17.29), in the case of multiple pregnancies (RR = 6.57, 95% CI 1.99-21.69) and maternal age ≥35 years (RR 2.10, 95% CI 1.01-4.35). In 17/29 cases the bleeding site was intra-pelvic (23.5% in the posterior uterine wall and 35.2% in the left hemipelvis). Laparotomy represented the surgical treatment in 27 cases (93%), and most women underwent a cesarean delivery (92.6%). Median blood loss was 1900 mL, one hysterectomy was necessary, and two women died. Twenty-two preterm births were recorded. CONCLUSIONS: Spontaneous hemoperitoneum in pregnancy is a rare, life-threatening condition associated with high perinatal morbidity and mortality. Maternal age ≥35 years, multiple pregnancies and assisted reproductive technology were associated to a higher risk of the condition. Two women of 29 died and 70% of births occurred preterm.