Amer J Perinatol 2018; 35(04): 380-384
DOI: 10.1055/s-0037-1607317
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Effect of Prior Term Birth on Risk of Recurrent Spontaneous Preterm Birth

Stephanie E. Purisch
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York
,
Amy L. Turitz
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York
,
Michal A. Elovitz
Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
,
Lisa D. Levine
Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
› Author Affiliations
Funding This study was funded in part by a National Institute of Health career development award in Women's Reproductive Health Research: K12-HD001265-14.
Further Information

Publication History

07 July 2017

14 September 2017

Publication Date:
27 October 2017 (eFirst)

Abstract

Objective The objective of this study was to evaluate the effect of prior term birth on recurrent spontaneous preterm birth (sPTB) risk.

Study Design Retrospective cohort study of 211 women with prior sPTB, comparing women with and without prior term births. The primary outcome was recurrent sPTB <37 weeks. Analyses stratified by gestational age of prior sPTB and adjusted for confounders using multivariable logistic regression.

Results The overall sPTB rate was 33.7%, with no statistical difference between women with and without prior term births (28.9 vs. 37.7%, p = 0.2). Among women with prior second-trimester loss (16–236/7 weeks), those with a term birth had a decreased sPTB rate (15.4 vs. 43.2%, p = 0.02), which persisted after adjusting for age and 17-α hydroxyprogesterone caproate use. For women with prior sPTB ≥24 weeks, there was no difference in sPTB with and without prior term births (29.5 vs. 26.6%, p = 0.7). A term birth as the most recent delivery lowered, but did not eliminate, the sPTB risk (19.1 vs. 36.4%, p = 0.1).

Conclusion Prior term birth lowers the risk of recurrent sPTB for women with prior second-trimester loss, but not for women with prior sPTB ≥24 weeks. Women with prior preterm and term births should be counseled accordingly and all sPTB prevention strategies should be recommended.