Hospital variation in utilization and success of trial of labor after a prior cesarean.

BACKGROUND: Trial of labor after cesarean delivery is an effective and safe option for women without contraindications.

OBJECTIVES: The objective of the study was to examine hospital variation in utilization and success of trial of labor after cesarean delivery and identify associated institutional characteristics and patient outcomes.

STUDY DESIGN: Using linked maternal and newborn hospital discharge records and birth certificate data in 2010-2012 from the state of California, we identified 146,185 term singleton mothers with 1 prior cesarean delivery and no congenital anomalies or clear contraindications for trial of labor at 249 hospitals. Risk-standardized utilization and success rates of trial of labor after cesarean delivery were estimated for each hospital after accounting for differences in patient case mix. Risk for severe maternal and newborn morbidities, as well as maternal and newborn length of stay, were compared between hospitals with high utilization and high success rates of trial of labor after cesarean delivery and other hospitals. Bivariate analysis was also conducted to examine the association of various institutional characteristics with hospitals' utilization and success rates of trial of labor after cesarean delivery.

RESULTS: In the overall sample, 12.5% of women delivered vaginally. After adjusting for patient clinical risk factors, utilization and success rates of trial of labor after cesarean delivery varied considerably across hospitals, with a median of 35.2% (10th to 90th percentile range: 10.2-67.1%) and 40.5% (10th to 90th percentile range: 8.5-81.1%), respectively. Risk-standardized utilization and success rates of trial of labor after cesarean delivery demonstrated an inverted U-shaped relationship such that low or excessively high use of trial of labor after cesarean delivery was associated with lower success rate. Compared with other births, those delivered at hospitals with above-the-median utilization and success rates of trial of labor after cesarean delivery had a higher risk for uterine rupture (adjusted risk ratio, 2.74, P < .001), severe newborn respiratory complications (adjusted risk ratio, 1.46, P < .001), and severe newborn neurological complications/trauma (adjusted risk ratio, 2.48, P < .001), but they had a lower risk for severe newborn infection (adjusted risk ratio, 0.80, P = .003) and overall severe unexpected newborn complications (adjusted risk ratio, 0.86, P < .001) as well as shorter length of stays (adjusted mean ratio, 0.948 for mothers and 0.924 for newborns, P < .001 for both). Teaching status, system affiliation, larger volume, higher neonatal care capacity, anesthesia availability, higher proportion of midwife-attended births, and lower proportion of Medicaid or uninsured patients were positively associated with both utilization and success of trial of labor after cesarean delivery. However, rural location and higher local malpractice insurance premium were negatively associated with the utilization of trial of labor after cesarean delivery, whereas for-profit ownership was associated with lower success rate.

CONCLUSION: Utilization and success rates of trial of labor after cesarean delivery varied considerably across hospitals. Strategies to promote vaginal birth should be tailored to hospital needs and characteristics (eg, increase availability of trial of labor after cesarean delivery at hospitals with low utilization rates while being more selective at hospitals with high utilization rates, and targeted support for lower capacity hospitals).