Maternal and hospital characteristics of non-medically indicated deliveries prior to 39 weeks.

Non-medically indicated (NMI) deliveries prior to 39 weeks increase the risk of neonatal mortality, excess morbidity, and health care costs. The study's purpose was to identify maternal and hospital characteristics associated with NMI deliveries prior to 39 weeks. The study included 207,775 births to women without a previous cesarean and 38,316 births to women with a previous cesarean, using data from Florida's 2006-2007 linked birth certificate and inpatient record file. Adjusted risk ratios (ARR) and 95 % confidence intervals (CI) for characteristics were calculated using generalized estimating equation for multinomial logistic regression. Among women without a previous cesarean, NMI deliveries occurred in 18,368 births (8.8 %). Non-medically indicated inductions were more likely in women who were non-Hispanic white (ARR: 1.41, 95 % CI 1.31-1.52), privately-insured (ARR: 1.42, 95 % CI 1.26-1.59), and delivered in hospitals with <500 births per year. Non-medically indicated primary cesareans were more likely in women who were older than 35 years (ARR: 2.96, 95 % CI 2.51-3.50), non-Hispanic white (ARR: 1.44, 95 % CI 1.30-1.59), and privately-insured (ARR: 1.43, 95 % CI 1.17-1.73). Non-medically indicated primary cesareans were also more likely to occur in hospitals with <30 % nurse-midwife births, <500 births per year, and in large metro areas. Among women with previous cesarean, NMI repeat cesareans occurred in 16,746 births (43.7 %). Only weak risk factors were identified for NMI repeat cesareans. The risk factors identified varied by NMI outcome. This information can be used to inform educational campaigns and identify hospitals that may benefit from quality improvement efforts.