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.
LEVEL OF EVIDENCE: II