Objective
Several studies in 2009, including a large cohort study from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network, found that early term delivery (37 0/7-38 6/7 weeks’ gestation) was associated with increased neonatal and infant morbidity and mortality compared to deliveries at ≥39 weeks. The NICHD study also found that over one third of nonmedically indicated cesarean deliveries occurred <39 weeks. Subsequently, in August 2009, the American Congress of Obstetricians and Gynecologists (ACOG) and later the Society for Maternal-Fetal Medicine (SMFM) published guidelines to discourage delivery <39 weeks’ gestation without a medical indication. Given that nearly one third of cesarean deliveries are done in the absence of labor or other recognized medical or obstetrical indications, this presented clinicians with an opportunity to change clinical practice and improve neonatal outcomes. Our objective was to examine the trend in early term repeat cesarean delivery rates from 2005 through 2014, before and after the publication of these recommendations.
Study Design
This is a study of the trend in timing of term repeat cesarean delivery in the United States from 2005 through 2014. We calculated the distribution of deliveries for each week of gestation between 35-41 weeks for total and repeat cesarean deliveries for 3 one-year time periods preceding (2005), coinciding with (2010), and following (2014) implementation of new guidelines using the National Vital Statistics System birth certificate data set. Because this study analyzes nonidentified data, it was deemed exempt from review by the Weill Cornell Investigation Review Board.
Study Design
This is a study of the trend in timing of term repeat cesarean delivery in the United States from 2005 through 2014. We calculated the distribution of deliveries for each week of gestation between 35-41 weeks for total and repeat cesarean deliveries for 3 one-year time periods preceding (2005), coinciding with (2010), and following (2014) implementation of new guidelines using the National Vital Statistics System birth certificate data set. Because this study analyzes nonidentified data, it was deemed exempt from review by the Weill Cornell Investigation Review Board.
Results
The study population consisted of 8,667,268 total deliveries of which 1,099,783 were repeat cesarean deliveries. The proportion of repeat cesarean deliveries at 38 weeks decreased from 28.7% in 2005 to 18.5% in 2014 (55.1% decrease; P < .001) and increased at 39 weeks from 30.5% in 2005 to 43.5% in 2014 (42.6% increase; P < .001) ( Figure ). The proportion of all deliveries at 38 weeks decreased from 19.7% in 2005 to 16.8% in 2014 (17.3% decrease; P < .001) and increased at 39 weeks from 26.7% in 2005 to 31.8% in 2014 (16% increase; P < .001). There were no significant changes from 2005 through 2014 in the proportion of deliveries between 35-37 weeks and 40-41 weeks.
