Downloaded from http://journals.lww.com/greenjournal by BhDMf5ePHKbH4TTImqenVAHxkFJp/XpPk1L/H3vMGwqMxG9jwOd8eJPG+b4DlKuAX44qu/vwzmc= on 07/30/2018 Original Research A Multi-State Analysis of Early-Term Delivery Trends and the Association With Term Stillbirth Sarah E. Little, MD, MPH, Chloe A. Zera, MD, MPH, Mark A. Clapp, MD, MPH, Louise Wilkins-Haug, MD, PhD, and Julian N. Robinson, MD OBJECTIVE: To investigate whether reduction in early- term deliveries was associated with increasing rates of term stillbirth. METHODS: This is a retrospective descriptive analysis of variation in term delivery timing and stillbirth from 2005 to 2011 based on birth certificate and fetal death data. Early- term deliveries (37 0/7–38 6/7 weeks of gestation) as a per- centage of total term delivery and term stillbirth rates were calculated for each state, both overall and for low- and high-risk women. We analyzed whether state-level changes in early-term deliveries and term stillbirth were correlated using Pearson correlation coefficients. States were also categorized as high or low reduction (above or below the national average) and changes in stillbirth rates for these groups were analyzed using a Cochrane- Armitage test for linear trend. RESULTS: There was a decline in early-term deliveries across the United States: 1,123,467 of 3,533,233 term, singleton births occurred in the early term in 2005 (31.8%) as compared with 978,294 of 3,429,172 (28.5%) in 2011. Reductions varied widely by state. There was no change in the term stillbirth rate (123/100,000 births in 2005 compared with 130/100,000 in 2011; P5 .189) nor change in the high reduction states alone. There was no correlation between state-level changes in early- term deliveries and term stillbirth. There was an increase in term stillbirths among women with diabetes (from 238/100,000 to 300/100,000 births; P5 .010), independent of changes in early-term delivery timing. CONCLUSION: The reduction in early-term deliveries across the United States between 2005 and 2011 was not associated with an increase in the rate of term stillbirth. (Obstet Gynecol 2015;126:1138–45) DOI: 10.1097/AOG.0000000000001109 LEVEL OF EVIDENCE: II A growing body of literature, starting as early as the mid-1990s, demonstrates that neonatal morbidity and mortality continues to decline, even at term, and reaches a nadir at 39–40 weeks of gestation. 1–7 As such, there have been multiple efforts across the United States by professional societies, regulatory bodies, and statewide quality collaboratives to lower the rate of nonmedically indicated delivery in the early term (37 0/7–38 6/7 weeks of gestation). 8–14 There is concern that 39-week delivery policies have the potential to increase the rate of term stillbirth if early-term deliveries are being shifted later in gestation, especially if policies are misapplied to higher risk pregnancies. There have been conflicting findings in the literature. Ehrenthal et al 10 found a threefold increased risk of stillbirth in the early term at a single institution; however Oshiro et al 12 found a twofold reduced risk. Furthermore, several studies have shown no statistically significant change. 11,15 Given these contradictory findings, our study analyzes the association between state-level early-term delivery trends and term stillbirth rates. A multistate analysis provides a large sample size and the ability to look at both high- and low-risk pregnancies. We used state-level data from the Centers for Disease Control and Prevention to look at reductions in early-term delivery from 2005 to 2011 and term stillbirth rates to See related editorial on page 1131. From the Division of Maternal-Fetal Medicine, Brigham and Women’s Hospital, and the Department of Obstetrics and Gynecology, Brigham and Women’s Hos- pital/Massachusetts General Hospital, Boston, Massachusetts. Corresponding author: Sarah E. Little, MD, MPH, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115; e-mail: selittle@partners.org. Financial Disclosure The authors did not report any potential conflicts of interest. © 2015 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0029-7844/15 1138 VOL. 126, NO. 6, DECEMBER 2015 OBSTETRICS & GYNECOLOGY Copyright ª by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.