Infant outcome after complete uterine rupture

Abstract

Background: Complete uterine rupture is a rare peripartum complication often associated with a catastrophic outcome for both mother and child. However, little has been written based on large data sets about maternal and infant outcome after complete ruptures. This is partly due to the rarity of the event and the serious maternal and infant outcome; it is also partly due to the use of international diagnostic codes that do not differentiate between the less catastrophic partial rupture and more catastrophic complete uterine rupture. As uterine rupture is expected to increase due to increased cesarean delivery rates worldwide, it is important to know more completely about the outcome following complete uterine rupture.

Objective: We sought to explore risk factors associated with poor infant outcome in cases of complete uterine rupture.

Study design: This population-based study used data from the Medical Birth Registry of Norway, the Patient Administration System, and medical records. We included births with complete uterine rupture after start of labor in all maternity units in Norway during the period 1967 through 2008 (n = 244 births), identified among 2,455,797 births. Uterine ruptures were identified and further studied through a review of medical records. We estimated the associations between infant outcomes and demographic and labor risk factors using logistic regression analyses. Odds ratios with 95% confidence intervals for each risk factor were determined after adjustment for demographic factors and period of birth. The main outcome measure was infant outcome: healthy infant, intrapartum/infant deaths, hypoxic ischemic encephalopathy, and admission to the neonatal intensive care unit.

Results: We identified 109 (44.7%) healthy infants, 56 (23.0%) infants needing neonatal intensive care unit admission, 64 (26.2%) intrapartum/infant deaths, and 15 (6.1%) infants with hypoxic ischemic encephalopathy. The highest number of intrapartum/infant deaths occurred in 1967 through 1977 (51.6%) and the fewest in 2000 through 2008 (15.0%). Unscarred uterine ruptures did not significantly increase intrapartum/infant deaths compared to scarred uterine ruptures. Placental separation and/or fetal extrusion had the highest odds ratio for intrapartum/infant deaths (odds ratio, 17.9; 95% confidence interval, 7.5-42.4). Time-to-delivery interval <20 minutes resulted in fewest intrapartum/infant deaths (9.9%), although there were 2 deaths at 10-minute interval. Time to delivery >30 minutes vs <20 minutes increased risk of death (odds ratio, 16.7; 95% confidence interval, 6.4-43.5).

Conclusion: Intrapartum/infant death after complete uterine rupture decreased significantly over the decades. Time to delivery >30 minutes and placental separation and/or fetal extrusion had the highest association with intrapartum/infant deaths after complete uterine rupture. Time to delivery <20 minutes limited the incidence of intrapartum/infant deaths.

Keywords: complete uterine rupture; hypoxic ischemic encephalopathy; infant extrusion; infant outcome; intrapartum/infant death; placental separation; risk factors; scarred uteri; time-to-delivery interval; unscarred uteri.