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Contemporary Labor Patterns and Maternal Age

Zaki, Mary N. MD; Hibbard, Judith U. MD; Kominiarek, Michelle A. MD

doi: 10.1097/AOG.0b013e3182a9c92c
Original Research

OBJECTIVE: To evaluate labor progress and length according to maternal age.

METHODS: Data were abstracted from the Consortium on Safe Labor, a multicenter retrospective study from 19 hospitals in the U.S. We studied 120,442 laboring gravid women with singleton, term, cephalic fetuses with normal outcomes and without a prior cesarean delivery from 2002 to 2008. Maternal age categories were younger than 20 years of age, 20–29 years of age, 30–39 years of age, and 40 years of age or older with the reference being younger than 20 years of age. Interval-censored regression analysis was used to determine median traverse times (progression centimeter by centimeter) with 95th percentiles adjusting for covariates (race, admission body mass index, diabetes, gestational age, induction, augmentation, epidural use, and birth weight). A repeated-measures analysis with an eighth-degree polynomial model was used to construct mean labor curves for each maternal age category stratified by parity.

RESULTS: Traverse times for nulliparous women demonstrated the time to progress from 4 to 10 cm decreased as age increased up to age 40 years (median 8.5 hours compared with 7.8 hours in those 20–29 years of age group and 7.4 hours in the 30–39 years of age group, P<.001); the length of the second stage with and without epidural increased with age (P<.001). For multiparous women, time to progress from 4 to 10 cm decreased as age increased (median 8.8 hours, 7.5, 6.7, and 6.5 from the youngest to oldest maternal age groups, P<.001). Labor progressed faster with increasing maternal age in both nulliparous and multiparous women in the labor curves analysis.

CONCLUSION: The first stage of labor progressed more quickly with increasing age for nulliparous women up to age 40 years and all multiparous women. Contemporary labor management should account for maternal age.


Older nulliparous and multiparous women progress faster in the first stage of labor.

Department of Obstetrics and Gynecology and the Division of Maternal Fetal Medicine, University of Illinois at Chicago, Chicago, Illinois.

Corresponding author: Mary N. Zaki, MD, University of Illinois at Chicago, 820 South Wood Street, M/C 808, Chicago, IL 60612; e-mail:

For a list of institutions involved in the Consortium on Safe Labor, see the Appendix online at

Supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH) (M.A.K, J.U.H.), through a contract (Contract No. HHSN267200603425C), Grant Number K12HD055892 from the NICHD and NIH Office of Research on Women's Health (ORWH) (M.A.K.) and the University of Illinois at Chicago (UIC) Center for Clinical and Translational Science (CCTS), Award Number UL1RR029879 from the National Center For Research Resources.

Presented as a poster at the Society for Gynecologic Investigation 59th Annual Scientific Meeting, March 21–24, 2012, San Diego, California.

The named authors alone are responsible for the views expressed in this article, which does not necessarily represent the decisions or the stated policy of the NICHD.

Financial Disclosure The authors did not report any potential conflicts of interest.

© 2013 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.