Safety of in-hospital versus out-of-hospital births

A population-based retrospective cohort study by researchers from Oregon is adding new data to the ongoing debate about the safety of giving birth outside of the hospital versus in the hospital. The results, say the authors, point to a low absolute risk of death in both settings but higher perinatal mortality for planned out-of-hospital than for planned in-hospital births.

Published in NEJM, the new report is from an analysis of all births that occurred in Oregon during 2012 and 2013. The state’s newly revised birth certificates allowed the authors to disaggregate data on hospital births into 2 categories: planned in-hospital births and planned out-of-hospital births that subsequently occurred in the hospital following the mother’s intrapartum transfer to the hospital. Researchers assessed perinatal morbidity and mortality, maternal morbidity, and obstetrical procedures according to the planned birth setting.

Of the 75,727 women with singletons represented in the study, 75,923 (95.2%) had planned in-hospital deliveries, 3203 (4%) had planned out-of-hospital births, and 601 women (0.8%) planned to deliver out-of-hospital but gave birth in the hospital following intrapartum transfer.

Related: Home birth: The obstetrician's ethical response 

Planned out-of-hospital birth was associated with a higher rate of perinatal death than was in-hospital birth (P=0.003, odds ratio [OR] after adjustment for maternal characteristics and 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). For planned out-of-hospital births, the odds of admission to a neonatal intensive care unit were lower but the odds of a neonatal seizure were higher with planned out-of-hospital births than with planned in-hospital births. Women who had a planned out-of-hospital birth also had a significantly increased risk of an unassisted vaginal delivery compared with those who had in-hospital births (93.8% vs 71.9%, P<0.001) and they also had lower odds of undergoing obstetrical procedures.

Commenting on the limitations of their study, the authors noted that for planned home births, they were unable to distinguish between transfers from birth centers and transfers from home. The findings, they said, may not be generalizable because the data are from a single state and one that has a relatively small number of births annually, albeit many of which occur out-of-hospital.