Planned Out-of-Hospital Birth and Birth Outcomes

Abstract

Background: The frequency of planned out-of-hospital birth in the United States has increased in recent years. The value of studies assessing the perinatal risks of planned out-of-hospital birth versus hospital birth has been limited by cases in which transfer to a hospital is required and a birth that was initially planned as an out-of-hospital birth is misclassified as a hospital birth.

Methods: We performed a population-based, retrospective cohort study of all births that occurred in Oregon during 2012 and 2013 using data from newly revised Oregon birth certificates that allowed for the disaggregation of hospital births into the categories of planned in-hospital births and planned out-of-hospital births that took place in the hospital after a woman's intrapartum transfer to the hospital. We assessed perinatal morbidity and mortality, maternal morbidity, and obstetrical procedures according to the planned birth setting (out of hospital vs. hospital).

Results: Planned out-of-hospital birth was associated with a higher rate of perinatal death than was planned in-hospital birth (3.9 vs. 1.8 deaths per 1000 deliveries, P=0.003; odds ratio after adjustment for maternal characteristics and medical conditions, 2.43; 95% confidence interval [CI], 1.37 to 4.30; adjusted risk difference, 1.52 deaths per 1000 births; 95% CI, 0.51 to 2.54). The odds for neonatal seizure were higher and the odds for admission to a neonatal intensive care unit lower with planned out-of-hospital births than with planned in-hospital birth. Planned out-of-hospital birth was also strongly associated with unassisted vaginal delivery (93.8%, vs. 71.9% with planned in-hospital births; P<0.001) and with decreased odds for obstetrical procedures.

Conclusions: Perinatal mortality was higher with planned out-of-hospital birth than with planned in-hospital birth, but the absolute risk of death was low in both settings. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.).

Figure 1. Association between Planned Out-of-Hospital Birth and a Composite Neonatal Outcome and Cesarean Delivery, According to Subgroups

Panel A shows a composite neonatal outcome (fetal death, infant death, a 5-minute Apgar score of less than 4, or neonatal seizures) in subgroups defined according to maternal characteristics. Panel B shows the rate of cesarean delivery according to the same maternal characteristics. An odds ratio of more than 1 indicates that the risk of the outcome is increased with planned out-of-hospital birth as compared with planned hospital birth. An odds ratio of less than 1 indicates that the risk of the outcome is decreased with planned out-of-hospital birth as compared with planned hospital birth. All the models were adjusted for maternal race or ethnic group, parity, insurance status (for cesarean delivery), extent of prenatal care, maternal age and education, history of cesarean delivery, and a composite of maternal conditions associated with an increased medical risk (chronic hypertension, gestational hypertension, preeclampsia, eclampsia, prepregnancy diabetes, or gestational diabetes). The sizes of the boxes are proportional to statistical precision. Horizontal lines represent 95% confidence intervals and arrows 95% confidence intervals that were clipped when the confidence limits extended to extreme values (e.g., odds ratios of 0.03 or 9.5) in order to maintain the readability of the central portion of the graph.