Development of a nomogram for prediction of vaginal birth after cesarean delivery.
OBJECTIVE
To develop a model based on factors available at the first prenatal visit that predicts chance of successful vaginal birth after cesarean delivery (VBAC) for individual patients who undergo a trial of labor.


METHODS
All women with one prior low transverse cesarean who underwent a trial of labor at term with a vertex singleton gestation were identified from a concurrently collected database of deliveries at 19 academic centers during a 4-year period. Using factors identifiable at the first prenatal visit, we analyzed different classification techniques in an effort to develop a meaningful prediction model for VBAC success. After development and cross-validation, this model was represented by a graphic nomogram.


RESULTS
Seven-thousand six hundred sixty women were available for analysis. The prediction model is based on a multivariable logistic regression, including the variables of maternal age, body mass index, ethnicity, prior vaginal delivery, the occurrence of a VBAC, and a potentially recurrent indication for the cesarean delivery. After analyzing the model with cross-validation techniques, it was found to be both accurate and discriminating.


CONCLUSIONS
A predictive nomogram, which incorporates six variables easily ascertainable at the first prenatal visit, has been developed that allows the determination of a patient-specific chance for successful VBAC for those women who undertake trial of labor.


METHODS
II.
Grobman
William A
WA
Department of Obstetrics and Gynecology at Northwestern University, Chicago, Illinois 60611, USA. w-grobman@northwestern.edu
Lai
Yinglei
Y
Landon
Mark B
MB
Spong
Catherine Y
CY
Leveno
Kenneth J
KJ
Rouse
Dwight J
DJ
Varner
Michael W
MW
Moawad
Atef H
AH
Caritis
Steve N
SN
Harper
Margaret
M
Wapner
Ronald J
RJ
Sorokin
Yoram
Y
Miodovnik
Menachem
M
Carpenter
Marshall
M
O'Sullivan
Mary J
MJ
Sibai
Baha M
BM
Langer
Oded
O
Thorp
John M
JM
Ramin
Susan M
SM
Mercer
Brian M
BM
D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D000075202:Contraindications; D005260:Female; D005544:Forecasting; D006801:Humans; D008423:Maternal Age; D049451:Nomograms; D011247:Pregnancy; D011248:Pregnancy Complications; D012372:ROC Curve; D044469:Racial Groups; D012189:Retrospective Studies; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean / Q000009:adverse effects