Am J Perinatol 2020; 37(04): 357-364
DOI: 10.1055/s-0039-1696641
SMFM Fellowship Series Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Association Between Features of Spontaneous Late Preterm Labor and Late Preterm Birth

Angelica V. Glover
1  Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
,
1  Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
,
Cynthia Gyamfi-Bannerman
2  Department of Obstetrics and Gynecology, Columbia University, New York, New York
,
Kim A. Boggess
1  Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
,
Grecio Sandoval
3  George Washington University Biostatistics Center, Washington, District of Columbia
,
Sean C. Blackwell
4  Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, The University of Texas Health Science Center at Houston, Children's Memorial Hermann Hospital, Houston, Texas
,
Alan T. N. Tita
5  Department of Obstetrics and Gynecology, The University of Alabama at Birmingham, Birmingham, Alabama
,
Uma M. Reddy
6  Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
,
Lucky Jain
7  Department of Obstetrics and Gynecology, Emory University, Atlanta, Georgia
,
George R. Saade
8  Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas
,
Dwight J. Rouse
9  Department of Obstetrics and Gynecology, Brown University, Providence, Rhode Island
,
Jay D. Iams
10  Department of Obstetrics and Gynecology, The Ohio State University, Columbus, Ohio
,
Erin A. S. Clark
11  Department of Obstetrics and Gynecology, University of Utah Health Sciences Center, Salt Lake City, Utah
,
Edward K. Chien
12  MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio
,
Alan M. Peaceman
13  Department of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois
,
14  Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado
,
Geeta K. Swamy
15  Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
,
Mary E. Norton
16  Department of Obstetrics and Gynecology, Stanford University, Stanford, California
,
Brian M. Casey
17  Department of Obstetrics and Gynecology, The University of Texas Southwestern Medical Center, Dallas, Texas
,
Steve N. Caritis
18  Department of Obstetrics and Gynecology, University of Pittsburg, Pittsburg, Pennsylvania
,
Jorge E. Tolosa
19  Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon
,
Yoram Sorokin
20  Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
,
Tracy A. Manuck
1  Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
,
for the Eunice Kennedy Shriver National Institute of Child Health Human Development Maternal-Fetal Medicine Units Network› Author Affiliations
Funding This study was supported by grants (HL098554 and HL098354) from the NHLBI, by grants (HD21410, HD27915, HD27917, HD27869, HD34116, HD34208, HD40485, HD40500, HD40512, HD40544, HD40545, HD40560, HD53097, HD53118, HD68268, HD68258, HD68282, and HD36801) from the NICHD, and by a grant (UL1 TR000040) from the National Center for Advancing Translational Sciences, National Institutes of Health. The views expressed in this article are those of the authors and do not necessarily represent the views of the National Institutes of Health.
Further Information

Publication History

29 March 2019

19 July 2019

Publication Date:
17 September 2019 (online)

Abstract

Objective This study aimed to evaluate the association between clinical and examination features at admission and late preterm birth.

Study Design The present study is a secondary analysis of a randomized trial of singleton pregnancies at 340/7 to 365/7 weeks' gestation. We included women in spontaneous preterm labor with intact membranes and compared them by gestational age at delivery (preterm vs. term). We calculated a statistical cut-point optimizing the sensitivity and specificity of initial cervical dilation and effacement at predicting preterm birth and used multivariable regression to identify factors associated with late preterm delivery.

Results A total of 431 out of 732 (59%) women delivered preterm. Cervical dilation ≥ 4 cm was 60% sensitive and 68% specific for late preterm birth. Cervical effacement ≥ 75% was 59% sensitive and 65% specific for late preterm birth. Earlier gestational age at randomization, nulliparity, and fetal malpresentation were associated with late preterm birth. The final regression model including clinical and examination features significantly improved late preterm birth prediction (81% sensitivity, 48% specificity, area under the curve = 0.72, 95% confidence interval [CI]: 0.68–0.75, and p-value < 0.01).

Conclusion Four in 10 women in late-preterm labor subsequently delivered at term. Combination of examination and clinical features (including parity and gestational age) improved late-preterm birth prediction.

Note

This study was presented as a poster at the 38th Annual Pregnancy Meeting, Society for Maternal-Fetal Medicine, February 1 to 3, 2018, Dallas, TX.


* Additional members of this network are listed in Appendix A.