Trial of labor or repeat cesarean delivery in women with morbid obesity and previous cesarean delivery.
OBJECTIVE
Assess effects of body mass index (BMI) on trial of labor after previous cesarean delivery and determine whether morbidly obese women have greater maternal and perinatal morbidity with trial of labor compared with elective repeat cesarean delivery.


METHODS
Secondary analysis from a prospective observational study included all term singletons undergoing trial of labor after previous cesarean delivery. Body mass index groups were as follows: normal 18.5-24.9, overweight 25.0-29.9, obese 30.0-39.9, morbidly obese 40.0 kg/m2 or greater, and were compared for failure and maternal and neonatal morbidities. The morbidly obese trial of labor and elective repeat cesarean delivery were compared for maternal and neonatal morbidities. Multivariable logistic regression analysis controlled for confounding variables.


RESULTS
There were 14,142 trial of labor participants and 14,304 elective repeat cesarean delivery participants. Increasing BMI was directly associated with failed trial of labor after previous cesarean delivery: from 15.2% in normal weight (1,344) to 39.3% in morbidly obese (1,638), with combined risk of rupture/dehiscence increasing from 0.9% to 2.1% in morbidly obese women. Among morbidly obese women, trial of labor carried greater than five-fold risk of uterine rupture/dehiscence (2.1% versus 0.4%), almost a two-fold increase in composite maternal morbidity (7.2% versus 3.8%) and five-fold risk of neonatal injury (1.1% versus 0.2%) (fractures, brachial plexus injuries, and lacerations), but no neonatal encephalopathy. Morbidly obese women failing a trial of labor had six-fold greater composite maternal morbidity than those undergoing a successful trial of labor (14.2% versus 2.6%).


CONCLUSIONS
Body mass index correlates with outcomes in trial of labor after previous cesarean delivery. Morbidly obese women undergoing a trial of labor were at increased risk for failure. Increased BMI was associated with greater composite morbidity and neonatal injury compared with elective repeat cesarean delivery, but absolute morbidities were small. Increased risks should be considered before trial of labor after previous cesarean delivery.


METHODS
II-2.
Hibbard
Judith U
JU
Department of Obstetrics and Gynecology, University of Chicago, Chicago, Illinois 60612, USA. jhibbar@uic.edu
Gilbert
Sharon
S
Landon
Mark B
MB
Hauth
John C
JC
Leveno
Kenneth J
KJ
Spong
Catherine Y
CY
Varner
Michael W
MW
Caritis
Steve N
SN
Harper
Margaret
M
Wapner
Ronald J
RJ
Sorokin
Yoram
Y
Miodovnik
Menachem
M
Carpenter
Marshall
M
Peaceman
Alan M
AM
O'Sullivan
Mary J
MJ
Sibai
Baha M
BM
Langer
Oded
O
Thorp
John M
JM
Ramin
Susan M
SM
Mercer
Brian M
BM
Gabbe
Steven G
SG
D000328:Adult; D015992:Body Mass Index; D017604:Cesarean Section, Repeat / Q000009:adverse effects / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009767:Obesity, Morbid / Q000150:complications*; D007744:Obstetric Labor Complications / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D011446:Prospective Studies; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean / Q000706:statistics & numerical data