Variations in Low-Risk Cesarean Delivery Rates in the United States Using the Society for Maternal-Fetal Medicine Definition

Abstract

To assess variations in low-risk cesarean delivery rates in the United States using the Society for Maternal-Fetal Medicine (SMFM) definition of low-risk for cesarean delivery and to identify factors associated with low-risk cesarean deliveries. METHODS:From hospital discharge data in the 2018 National Inpatient Sample and State Inpatient Databases, we identified deliveries that were low-risk for cesarean delivery using the SMFM definition based on the International Classification of Diseases, Tenth Revision, Clinical Modification codes. We estimated national low-risk cesarean delivery rates overall and by patient characteristics, clinically relevant conditions not included in the SMFM definition, and hospital characteristics based on the nationally representative sample of hospital discharges in the National Inpatient Sample. Multivariate logistic regressions were estimated for the national sample to identify factors associated with low-risk cesarean delivery. We reported low-risk cesarean delivery rates for 27 states and the District of Columbia based on the annual state data that represented the universe of hospital discharges from participating states in the State Inpatient Databases.RESULTS: Of an estimated 3,634,724 deliveries in the 2018 National Inpatient Sample, 2,484,874 low-risk deliveries met inclusion criteria. The national low-risk cesarean delivery rate in 2018 was 14.6% (95% CI 14.4-14.8%). The rates varied widely by state (range 8.9-18.6%). Nationally, maternal age older than 40 years, non-Hispanic Black or Asian race, private insurance as primary payer, admission on weekday, obesity, diabetes, or hypertension, large metropolitan residence, and hospitals of the South census region were associated with lowrisk cesarean delivery.CONCLUSION: Approximately one in seven low-risk deliveries was by cesarean in 2018 in the United States using the SMFM definition and the low-risk cesarean delivery rates varied widely by state.

Cesarean Delivery Trends Among Patients at Low Risk for Cesarean Delivery in the US, 2000-2019

“…This differential was not surprising given that our analysis excluded additional risk factors for cesarean birth and included delivery hospitalizations of patients with prior vaginal births. Similar to prior analyses evaluating births at low risk for cesarean delivery in the NIS, our analysis found a modest increase in the likelihood of cesarean delivery associated with demographic factors and hospital characteristics, including older maternal age, private insurance, and hospitals in the South …”

“…Similar to prior analyses evaluating births at low risk for cesarean delivery in the NIS, our analysis found a modest increase in the likelihood of cesarean delivery associated with demographic factors and hospital characteristics, including older maternal age, private insurance, and hospitals in the South. 32 A key finding of this analysis was that although overall cesarean birth rates decreased, particularly in the setting of labor disorder diagnoses, cesarean births with a diagnosis of nonreassuring fetal status increased. Nomenclature and interpretation of intrapartum electronic fetal heart rate (FHR) monitoring also underwent changes over this study period.…”

“…Similar to prior analyses evaluating births at low risk for cesarean delivery in the NIS, our analysis found a modest increase in the likelihood of cesarean delivery associated with demographic factors and hospital characteristics, including older maternal age, private insurance, and hospitals in the South. 32 …”

Midwifery Workforce Density Moderates the Association Between Independent Practice and Pregnancy Outcomes

“…Women with a risk factor have a higher rate of NTSV cesarean compared with women without risk factors. 17,26,27 Markowitz et al controlled for birthing person risk but were limited to the variables available in the birth certificate. 9 The current study used the Agency for Healthcare Research and Quality definition of low-risk primary cesarean, which excludes cases with an indication for cesarean.…”

“…However, 24% of women who meet the criteria for NTSV have a risk factor for cesarean. Women with a risk factor have a higher rate of NTSV cesarean compared with women without risk factors 17,26,27 . Markowitz et al controlled for birthing person risk but were limited to the variables available in the birth certificate 9 .…”