Neonatal outcomes of births in freestanding birth centers and hospitals in the United States, 2016-2019

BACKGROUND: Births in freestanding birth centers have more than doubled between 2007 and 2019. Although birthing centers, which are defined by the American College of Obstetricians and Gynecologists as "... freestanding facilities that are not hospitals," are being promoted as offering women fewer interventions than hospitals, there are limited recent data available on neonatal outcomes in these settings. OBJECTIVE: To compare several important measures of neonatal safety between 2 United States birth settings and birth attendants: deliveries in freestanding birth centers and hospital deliveries by midwives and physicians. STUDY DESIGN: This is a retrospective cohort study using the United States Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics, and Division of Vital Statistics natality online database for the years 2016 to 2019. All term, singleton, low-risk births were eligible for inclusion. The study outcomes were several neonatal outcomes including neonatal death, neonatal seizures, 5-minute Apgar scores of <4 and <7, and neonatal death in nulliparous and in multiparous women. Outcomes were compared between the following 3 groups: births in freestanding birth centers, inhospital births by a physician, and in-hospital births by a midwife. The prevalence of each neonatal outcome among the different groups was compared using Pearson chi-squared test, with the in-hospital midwife births being the reference group. Multivariate logistic regression models were performed to account for several potential confounding factors such as maternal prepregnancy body mass index, maternal weight gain, parity, gestational weeks, and neonatal birthweight and calculated as adjusted odds ratio. RESULTS: The study population consisted of 9,894,978 births; 8,689,467 births (87.82%) were in-hospital births by MDs and DOs, 1,131,398 (11.43%) were in-hospital births by midwives, and 74,113 (0.75%) were births in freestanding birth centers. Freestanding birth center deliveries were less likely to be to non-Hispanic Black or Hispanic, less likely to women with public insurance, less likely to be women with their first pregnancy, and more likely to be women with advanced education and to have pregnancies at >= 40 weeks' gestation. Births in freestanding birth center had a 4-fold increase in neonatal deaths (3.64 vs 0.95 per 10,000 births: adjusted odds ratio, 4.00; 95% confidence interval, 2.62-6.1), a more than 7-fold increase in neonatal deaths for nulliparous patients (6.8 vs 0.92 per 10,000 births: adjusted odds ratio, 7.7; 95% confidence interval, 4.42-13.76), a more than 2-fold increase in neonatal seizures (3.91 vs 1.94 per 10,000 births: adjusted odds ratio, 2.19; 95% confidence interval, 1.48-3.22), and a more than 7-fold increase of a 5-minute Apgar score of <4 (194.84 vs 28.5 per 10,000 births: adjusted odds ratio, 7.46; 95% confidence interval, 7-7.95). Compared with hospital midwife deliveries, hospital physician deliveries had significantly higher adverse neonatal outcomes (P<0.001). CONCLUSION: Births in United States freestanding birth centers are associated with an increased risk of adverse neonatal outcomes such as neonatal deaths, seizures, and low 5-minute Apgar scores. Therefore, when counseling women about the location of birth, it should be conveyed that births in freestanding birth centers are not among the safest birth settings for neonates compared with hospital births attended by either midwives or physicians.