Labor patterns in women attempting vaginal birth after cesarean with normal neonatal outcomes.
OBJECTIVE
We sought to describe labor patterns in women with a trial of labor after cesarean (TOLAC) with normal neonatal outcomes.


METHODS
In a retrospective observational study at 12 US centers (2002 through 2008), we examined time interval for each centimeter of cervical dilation and compared labor progression stratified by spontaneous or induced labor in 2892 multiparous women with TOLAC (second delivery) and 56,301 nulliparous women at 37 0/7 to 41 6/7 weeks of gestation. Analyses were performed including women with intrapartum cesarean delivery, and also limiting only to women who delivered vaginally.


RESULTS
Labor was induced in 23.4% of TOLAC and 44.1% of nulliparous women (P < .001). Cesarean delivery rates were 57.7% in TOLAC vs 19.0% in nulliparous women (P < .001). Oxytocin was used in 52.4% of TOLAC vs 64.3% of nulliparous women with spontaneous labor (P < .001) and 89.8% of TOLAC vs 91.6% of nulliparous women with induced labor (P = .099); however, TOLAC had lower maximum doses of oxytocin compared to nulliparous women: median (90th percentile): 6 (18) mU/min vs 12 (28) mU/min, respectively (P < .001). Median (95th percentile) labor duration for TOLAC vs nulliparous women with spontaneous labor from 4-10 cm was 0.9 (2.2) hours longer (P = .007). For women who entered labor spontaneously and achieved vaginal delivery, labor patterns for TOLAC were similar to nulliparous women. For induced labor, labor duration for TOLAC vs nulliparous women from 4-10 cm was 1.5 (4.6) hours longer (P < .001). For women who achieved vaginal delivery, labor patterns were slower for induced TOLAC compared to nulliparous women.


CONCLUSIONS
Labor duration for TOLAC was slower compared to nulliparous labor, particularly for induced labor. By improved understanding of the rates of progress at different points in labor, this new information on labor curves in women undergoing TOLAC, particularly for induction, should help physicians when managing labor.
Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD. Electronic address: katherine.grantz@nih.gov.
Katherine L
KL
Grantz
Department of Obstetrics and Gynecology, University of Miami School of Medicine, Miami, FL.
Victor
V
Gonzalez-Quintero
Office of Biostatistics Research, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.
James
J
Troendle
Pregnancy and Perinatology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Uma M
UM
Reddy
Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Stefanie N
SN
Hinkle
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Illinois College of Medicine at Chicago, Chicago, IL.
Michelle A
MA
Kominiarek
Glotech Inc, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Zhaohui
Z
Lu
Ministry of Education-Shanghai Key Lab of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Jun
J
Zhang
D000328:Adult; D016022:Case-Control Studies; D017604:Cesarean Section, Repeat / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007751:Labor, Induced; D007743:Labor, Obstetric / Q000502:physiology*; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean; D055815:Young Adult
first stage of labor; trial of labor after cesarean; vaginal birth after cesarean