Adverse Maternal and Neonatal Outcomes in Indicated Compared with Spontaneous Preterm Birth in Healthy Nulliparas: A Secondary Analysis of a Randomized Trial

Abstract

Objective To compare the risks of adverse maternal and neonatal outcomes associated with spontaneous (SPTB) versus indicated preterm births (IPTB).

Methods A secondary analysis of a multicenter trial of vitamin C and E supplementation in healthy low-risk nulliparous women. Outcomes were compared between women with SPTB (due to spontaneous membrane rupture or labor) and those with IPTB (due to medical or obstetric complications). A primary maternal composite outcome included: death, pulmonary edema, blood transfusion, adult respiratory distress syndrome (RDS), cerebrovascular accident, acute tubular necrosis, disseminated intravascular coagulopathy, or liver rupture. A neonatal composite outcome included: neonatal death, RDS, grades III or IV intraventricular hemorrhage (IVH), sepsis, necrotizing enterocolitis (NEC), or retinopathy of prematurity.

Results Of 9,867 women, 10.4% (N = 1,038) were PTBs; 32.7% (n = 340) IPTBs and 67.3% (n = 698) SPTBs. Compared with SPTB, the composite maternal outcome was more frequent in IPTB—4.4% versus 0.9% (adjusted odds ratio [aOR], 4.0; 95% confidence interval [CI], 1.4–11.8), as were blood transfusion and prolonged hospital stay (3.2 and 3.7 times, respectively). The frequency of composite neonatal outcome was higher in IPTBs (aOR, 1.8; 95% CI, 1.1–3.0), as were RDS (1.7 times), small for gestational age (SGA) < 5th percentile (7.9 times), and neonatal intensive care unit (NICU) admission (1.8 times).

Conclusion Adverse maternal and neonatal outcomes were significantly more likely with IPTB than with SPTB.

Keywords

spontaneous preterm birth - indicated preterm birth - preeclampsia - pregnancy outcomes

Note

This study was conducted with the ethics board approval from each of the participating clinical centers and the data coordinating center. This study was presented in part at the 32nd Annual meeting of the Society for Maternal-Fetal Medicine in Dallas, TX, on February 8–11, 2012.

Authors' Contribution

All authors approve of this submission and agree to be accountable for all aspects of the work as related to accuracy and integrity. In addition, authors contributed as follows: A.T.T. contributed to the conception and design analysis and interpretation of data and drafted and revised the manuscript. L.D. contributed to the design, acquisition of data, data analysis, and interpretation and contributed to the drafting and revision of the manuscript; J.M.R. and L.M. contributed to conception and design, analysis, and interpretation and revised the article critically; and all other authors (K.J.L., M.W.V., R.J.W., J.M.T., B.M.M., A.P., S.M.R., M.W.C., J.I., A.S., M.H., J.E.T., G.S., Y.S.) contributed to acquisition of data, analysis, and interpretation and revising the article critically.

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