Neonatal Outcomes Associated With Placental Abruption

Abstract

Placental abruption (early separation of the placenta) is associated with preterm birth and perinatal mortality, but associations with other neonatal morbidities remain understudied. We examined the association between abruption and newborn outcomes. We analyzed 223,341 singleton deliveries from the Consortium on Safe Labor study, a retrospective, multisite, observational study (2002-2008) of electronic medical records in the United States. Adjusted relative risks, incidence rate ratios, and 99% confidence intervals were estimated. Direct effects attributable to abruption were examined by conditioning on intermediates (preterm birth and small for gestational age) with sensitivity analyses. Incidence of abruption was 1.6% (n = 3,619). Abruption was associated with an elevated risk of newborn resuscitation (relative risk (RR) = 1.5, 99% confidence interval (CI): 1.5, 1.6), apnea (RR = 5.8, 99% CI: 5.1, 6.5), asphyxia (RR = 8.5, 99% CI: 5.7, 11.3), respiratory distress syndrome (RR = 6.5, 99% CI: 5.9, 7.1), neonatal intensive care unit admission (RR = 3.4, 99% CI: 3.2, 3.6), longer intensive care length of stay (incidence rate ratio = 2.0, 99% CI: 1.9, 2.2), stillbirth (RR = 6.3, 99% CI: 4.7, 7.9), and neonatal mortality (RR = 7.6, 99% CI: 5.2, 10.1). In sensitivity analyses, there was a direct effect of abruption associated with increased neonatal risks. These findings expand our knowledge of the association between abruption and perinatal and neonatal outcomes.

Keywords: abruption; apnea; neonatal morbidity; perinatal mortality; respiratory distress syndrome.

Figure 1.

Directed acyclic graphs illustrating theoretical relationships between placental abruption, preterm birth, growth restriction, and perinatal and neonatal morbidity and mortality. Underlying placental dysfunction due to inadequate trophoblast invasion, inflammation, and/or abnormal remodeling of the spiral arteries could lead to placental abruption, preterm birth, and growth restriction. Potential direct, indirect (dashed line), and independent relationships are shown for preterm birth (A) and growth restriction (B). Both scenarios could be affected by secondary placental dysfunction resulting from maternal factors, such as smoking or chronic hypertension, as well possible unmeasured confounders (U).