Changes in Delivery Timing for High-Risk Pregnancies in the United States

Abstract

Objective This study was aimed to assess whether the “39-week” rule is being extended to high-risk pregnancies and if so whether this has led to changes in neonatal morbidity or stillbirth.

Study Design Birth certificate data between 2010 and 2014 from 23 states (55% of births in the United States) were used. Pregnancies were classified as high risk if they had any one of the following: maternal age greater than or equal to 40 years, prepregnancy body mass index (BMI) greater than or equal to 40 kg/m², chronic (prepregnancy) hypertension, or diabetes (pregestational or gestational). Delivery timing changes for all pregnancies at term (37 weeks or greater) were compared with changes in the high-risk population. Neonatal morbidities (neonatal intensive care unit [NICU] admission, need for assisted ventilation, 5-minute Apgar score, and macrosomia), maternal morbidities (intensive care unit [ICU] admission, cesarean delivery, operative vaginal delivery, chorioamnionitis, and severe perineal laceration), and stillbirth rates were compared across time periods. Multivariate logistic regression was used to analyze whether gestational age–specific morbidity changes were due to shifts in delivery timing.

Results For the overall population, there was a shift in delivery timing between 2010 and 2014, a 2.5% decrease in 38-week deliveries, and a 2.3% increase in 39-week deliveries (p < 0.01). This gestational age shift was identical in the high-risk population (2.7% decrease in 38-week deliveries and 2.9% increase in 39-week deliveries). For the high-risk population, NICU admission increased from 5.4 to 6.3% in 2014 (p < 0.01) and assisted ventilation rates declined from 3.8 to 2.9% (p < 0.01). These changes, however, were independent of changes in delivery timing. There was no increase in the rate of stillbirth (0.23% in 2010 and 0.23% in 2014; p = 0.50).

Conclusion There was a significant shift in delivery timing for high-risk pregnancies in the United States between 2010 and 2014. This shift, however, did not result in statistically significant changes in either neonatal morbidity or stillbirth.

Key Points

• From 2010 to 2014, term deliveries for high-risk pregnancies shifted towards 39 weeks.

• The shift towards 39 weeks in high-risk pregnancies was not accompanied by any improvement in neonatal morbidity.

• The shift towards 39 weeks in high-risk pregnancies did not result in an increase in the stillbirth rate.

Keywords

39-week rule - nonmedically indicated induction - elective induction - delivery timing

Note

This study was presented orally at the 38th Annual Pregnancy Meeting of the Society for Maternal-Fetal Medicine, January 29 to February 3, 2018, Dallas, TX.

Publikationsverlauf

Eingereicht: 03. Januar 2020

Angenommen: 27. April 2020

Artikel online veröffentlicht:
11. Juni 2020

• References

• 1 Tita AT, Landon MB, Spong CY. et al; Eunice Kennedy Shriver NICHD Maternal-Fetal Medicine Units Network. Timing of elective repeat cesarean delivery at term and neonatal outcomes. N Engl J Med 2009; 360 (02) 111-120
• 2 Hibbard JU, Wilkins I, Sun L. et al; Consortium on Safe Labor. Respiratory morbidity in late preterm births. JAMA 2010; 304 (04) 419-425
• 3 Chiossi G, Lai Y, Landon MB. et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network. Timing of delivery and adverse outcomes in term singleton repeat cesarean deliveries. Obstet Gynecol 2013; 121 (03) 561-569
• 4 Crump C, Sundquist K, Winkleby MA, Sundquist J. Early-term birth (37-38 weeks) and mortality in young adulthood. Epidemiology 2013; 24 (02) 270-276
• 5 Helle E, Andersson S, Häkkinen U, Järvelin J, Eskelinen J, Kajantie E. Morbidity and health care costs after early term birth. Paediatr Perinat Epidemiol 2016; 30 (06) 533-540
• 6 Sengupta S, Carrion V, Shelton J. et al. Adverse neonatal outcomes associated with early-term birth. JAMA Pediatr 2013; 167 (11) 1053-1059
• 7 American College of Obstetricians and Gynecologists. ACOG committee opinion no. 561: Nonmedically indicated early-term deliveries. Obstet Gynecol 2013; 121: 911-915
• 8 Oshiro BT, Kowalewski L, Sappenfield W. et al. A multistate quality improvement program to decrease elective deliveries before 39 weeks of gestation. Obstet Gynecol 2013; 121 (05) 1025-1031
• 9 Main E, Oshiro B, Chagolla B, Bingham D, Dang-Kilduff L, Kowalewski L. California Maternal Quality Care Collaborative. Elimination of Non-medically Indicated (Elective) Deliveries Before 39 Weeks Gestational Age. Accessed May 11, 2020 at: https://www.leapfroggroup.org/sites/default/files/Files/LessThan39WeeksToolkit.pdf
• 10 Donovan EF, Lannon C, Bailit J, Rose B, Iams JD, Byczkowski T. ; Ohio Perinatal Quality Collaborative Writing Committee. A statewide initiative to reduce inappropriate scheduled births at 36(0/7)-38(6/7) weeks' gestation. Am J Obstet Gynecol 2010; 202 (03) 243.e1-243.e8
• 11 Ehrenthal DB, Hoffman MK, Jiang X, Ostrum G. Neonatal outcomes after implementation of guidelines limiting elective delivery before 39 weeks of gestation. Obstet Gynecol 2011; 118 (05) 1047-1055
• 12 Little SE, Robinson JN, Puopolo KM. et al. The effect of obstetric practice change to reduce early term delivery on perinatal outcome. J Perinatol 2014; 34 (03) 176-180
• 13 Snowden JM, Muoto I, Darney BG. et al. Oregon's hard-stop policy limiting elective early-term deliveries: association with obstetric procedure use and health outcomes. Obstet Gynecol 2016; 128 (06) 1389-1396
• 14 Nicholson JM, Kellar LC, Ahmad S. et al. US term stillbirth rates and the 39-week rule: a cause for concern?. Am J Obstet Gynecol 2016; 214 (05) 621.e1-621.e9
• 15 Pilliod RA, Dissanayake M, Cheng YW, Caughey AB. Association of widespread adoption of the 39-week rule with overall mortality due to stillbirth and infant death. JAMA Pediatr 2019 (e-pub ahead of print) Doi: 10.1001/jamapediatrics.2019.3939
• 16 Little SE, Zera CA, Clapp MA, Wilkins-Haug L, Robinson JN. A multi-state analysis of early-term delivery trends and the association with term stillbirth. Obstet Gynecol 2015; 126 (06) 1138-1145
• 17 MacDorman MF, Reddy UM, Silver RM. Trends in stillbirth by gestational age in the United States, 2006-2012. Obstet Gynecol 2015; 126 (06) 1146-1150
• 18 Oshiro BT, Henry E, Wilson J, Branch DW, Varner MW. Women and Newborn Clinical Integration Program. Decreasing elective deliveries before 39 weeks of gestation in an integrated health care system. Obstet Gynecol 2009; 113 (04) 804-811 Z edVXzü
• 19 Center for Disease Control. National Center for Health Statistics: Vital Statistics Online Data Portal. Accessed April 24, 2020 at: https://www.cdc.gov/nchs/data_access/vitalstatsonline.htm
• 20 Centers for Disease Control. User guide to the 2010 natality public use data file. Accessed January 3, 2020 at: https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2011.pdf
• 21 Gregory ECW, MacDorman MF, Martin JA. Trends in fetal and perinatal mortality in the United States, 2006–2012. NCHS Data Brief 2014; (169) 1-8
• 22 Harrison WN, Wasserman JR, Goodman DC. Regional variation in neonatal intensive care admissions and the relationship to bed supply. J Pediatr 2018; 192: 73-79.e4
• 23 Dietz PM, Bombard JM, Hutchings YL. et al. Validation of obstetric estimate of gestational age on US birth certificates. Am J Obstet Gynecol 2014; 210 (04) 335.e1-335.e5
• 24 Martin JA, Wilson EC, Osterman MJK. et al. Assessing the quality of medical and health data from the 2003 birth certificate revision: Results from two states. National Vital Stat Rep 2013; 62 (02) 1-19
• 25 Dietz P, Bombard J, Mulready-Ward C. et al. Validation of selected items on the 2003 U.S. standard certificate of live birth: New York City and Vermont. Public Health Rep 2015; 130 (01) 60-70
• 26 Haghighat N, Hu M, Laurent O, Chung J, Nguyen P, Wu J. Comparison of birth certificates and hospital-based birth data on pregnancy complications in Los Angeles and Orange County, California. BMC Pregnancy Childbirth 2016; 16: 93
• 27 Martin JA, Wilson EC, Osterman MJ, Saadi EW, Sutton SR, Hamilton BE. Assessing the quality of medical and health data from the 2003 birth certificate revision: results from two states. Natl Vital Stat Rep 2013; 62 (02) 1-19