Trial of labor (TOL) after a previous cesarean section (CS) is one of the tools to reduce the increasing CS rate. The safety and efficacy of induction of labor (IOL) in these patients is still controversial. The aims of the study were: 1) to determine the success rate of IOL in women with a prior low-transverse CS; 2) to compare the perinatal outcome of a TOL in women with one prior CS who had an IOL, spontaneous TOL, or an elective repeat CS (RECS).
A retrospective cohort study, including all patients with a prior low-transverse CS in their subsequent delivery of a vertex singleton in our medical center from 1988 until 2005 (n=7755). The maternal and neonatal demographical and medical data were obtained from a computerized database. The patients were classified into three groups: 1) women who underwent RECS (n= 1916); 2) women who had a spontaneous TOL (n= 4263); and 3) women who underwent IOL (n=1576).
1) the rate of IOL in the study cohort was 20.3%, and 67.4% of those who had IOL had a VBAC; 2) patient in the spontaneous TOL had a VBAC rate of 72.9% which is higher than that of the IOL group (p <0.001); 3) repeated CS due to labor dystocia were more prevalent in women in the IOL group than in the spontaneous TOL group (22.5% vs. 9.95%, OR 2.62, 95% CI 2.24-3.06); 4) the rate of uterine rupture was comparable among all study groups; 5) post partum infectious morbidity was higher among patients in the IOL group than in those who had a spontaneous TOL or an RECS (p<0.001); 7) in a multivariable analysis, labor dystocia at previous pregnancy, maternal illness, and IOL, were all independent risk factors for repeated CS.
1) IOL in patients with a previous CS is successful in about 2/3 of the cases; 2) nevertheless, in comparison to spontaneous onset of labor, IOL is an independent risk factor for repeated CS; 2) the rate of labor dystocia is higher among patients who had an IOL than those delivering spontaneously; and 3) a risk assessment model for the success of TOL by an IOL after a CS is needed.
© 2012 Mosby, Inc. Published by Elsevier Inc. All rights reserved.