Amer J Perinatol
DOI: 10.1055/s-0037-1608804
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Neonatal Outcomes Differ after Spontaneous and Indicated Preterm Birth

Molly J. Stout1, Devyn Demaree1, *, Emily Merfeld2, *, Methodius G. Tuuli1, Jennifer A. Wambach2, F. Sessions Cole2, Alison G. Cahill1
  • 1Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis Children's Hospital, St. Louis, Missouri
  • 2Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis Children's Hospital, St. Louis, Missouri
Further Information

Publication History

08 May 2017

12 October 2017

Publication Date:
28 November 2017 (eFirst)


Objective Preterm birth (PTB) at <37 weeks of gestation complicates 10% of pregnancies and requires accurate counseling regarding anticipated neonatal outcomes. PTB classification as spontaneous or indicated is commonly used to cluster PTB into subtypes, but whether neonatal outcomes differ by PTB subtype is unknown. We tested the hypothesis that neonatal morbidity differs based on subtype of PTB.

Methods We performed a retrospective cohort study of live-born, non-anomalous preterm infants from 2004 to 2008. Spontaneous PTB was defined as PTB from spontaneous preterm labor or preterm rupture of membranes. Indicated PTB was defined as PTB from any maternal or fetal medical complication necessitating delivery. The primary outcome was a composite of early respiratory morbidity. Secondary outcomes included late composite respiratory morbidity and other neonatal morbidities.

Results Of 1,223 preterm neonates, 60.9% were born after spontaneous PTB and 30.1% after indicated PTB. Composite early respiratory morbidity was significantly higher after indicated PTB versus spontaneous PTB (1.3, 95% confidence interval [CI] 1.2–1.4). Composite late respiratory morbidity (1.8, 95% CI 1.3–2.3) and neonatal death (2.8, 95% CI 1.5–5.1) were also significantly higher after indicated PTB versus spontaneous PTB.

Conclusion Neonatal respiratory outcomes and death differ according to PTB subtype. PTB subtype should be considered while counseling families and anticipating neonatal outcomes after PTB.


This work was presented at the Society for Maternal–Fetal Medicine Annual Meeting in February 2015, San Diego, California.


Dr. Stout received funding from NIH/NICHD T32 (5 T32 HD055172–02), Washington University CTSA grant (UL1 TR000448) and The March of Dimes Prematurity Research Center at Washington University in Saint Louis. Drs. Stout and Tuuli received funding from NIH/NICHD Women's Reproductive Health Research Career Development Program at Washington University in St. Louis (5K12HD063086–05), and Dr. Wambach received funding from National Institutes of Health (K08 1058910, the American Lung Association, and the American Thoracic Society. Dr. Cole received funding from NIH/NHLBI K12 HL120002, and R33 HL120760, and the Saigh Foundation. Drs. Wambach and Cole received funding from the Children's Discovery Institute. Dr. Cahill received funding from NIH/NICHD 5U01HD077384–02 and NIH/NICHD R01HD061619.

* Both the authors contributed equally to this work.