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

Importance: Reducing rates of unnecessary cesarean deliveries is both a national and a global health objective. However, there are limited national US data on trends in indications for low-risk cesarean delivery. Objective: To determine temporal trends in and indications for cesarean delivery among patients at low risk for the procedure over a 20-year period. Design, Setting, and Participants: This cross-sectional study analyzed 2000 to 2019 delivery hospitalizations using the National Inpatient Sample. Births at low risk for cesarean delivery were identified using a definition from the Society for Maternal-Fetal Medicine and additional criteria. Temporal trends in cesarean birth were analyzed using joinpoint regression to estimate the average annual percentage change (AAPC) with 95% CIs. Data analysis was performed from August 2022 to January 2023. Exposure: This analysis evaluated cesarean birth trends in a population at low risk for this procedure over a 20-year period. Main Outcomes and Measures: In addition to overall cesarean birth risk, cesarean deliveries for nonreassuring fetal status and labor arrest were individually analyzed. Results: Of an estimated 76.7 million delivery hospitalizations, 21.5 million were excluded according to the Society for Maternal-Fetal Medicine definition, and 14.7 million were excluded according to additional criteria. Of the estimated 40 517 867 deliveries included, 12.1% (4 885 716 deliveries) were by cesarean delivery. Cesarean deliveries among patients at low risk for the procedure increased from 9.7% to 13.9% between 2000 and 2009, plateaued, and then decreased from 13.0% to 11.1% between 2012 and 2019. The AAPC for cesarean delivery was 6.4% (95% CI, 5.2% to 7.6%) from 2000 to 2005, 1.2% from 2005 to 2009 (95% CI, -1.2% to 3.7%), and -2.2% from 2009 to 2019 (95% CI, -2.7% to -1.8%). Cesarean delivery for nonreassuring fetal status increased from 3.4% of all deliveries in 2000 to 5.1% in 2019 (AAPC, 2.1%; 95% CI, 1.7% to 2.5%). Cesarean delivery for labor arrest increased from 3.6% in 2000 to a peak of 4.8% in 2009 before decreasing to 2.7% in 2019. Cesarean deliveries for labor arrest increased during the first half of the study (2000-2009) for the active phase (from 1.5% to 2.1%), latent phase (from 1.1% to 1.5%), and second stage (from 0.9% to 1.3%) and then decreased from 2010 to 2019, from 2.1% to 1.7% for the active phase, from 1.5% to 1.2% for the latent phase, and from 1.2% to 0.9% for the second stage. Conclusions and Relevance: Cesarean deliveries among patients at low risk for cesarean birth appeared to decrease over the latter years of the study period, with cesarean deliveries for labor arrest becoming less common.