Korean J Obstet Gynecol.  2007 Dec;50(12):1640-1649.

Evaluation of the factors affecting the success of the trial of vaginal birth and duration of labor in women with previous cesarean section

• Kang EJ
• Lee KA
• Park MH
• Kim YJ
• Chun SH
• Ahn JJ

Abstract

OBJECTIVE
The purpose of this study was to determine which factors influence the likelihood of successful trial of labor, to evaluate the risks of VBAC and to evaluate the criteria of dystocia and the safety of VBAC.
METHODS
This retrospective study was peformed based on 61 pregnant women who succeeded VBAC, 37 VBAC failure women, 100 nulliparas and 100 multiparas.
RESULTS
In clinical characteristics, the parity, the number of previous cesarean section, gestational age, estimated fetal body weight by ultrasonography, and neonatal body weight had notable differences between the success and the failure group. In obstetric and historical factors, cervical effacement, dilation, and Bishop score at admission, spontaneous labor and method of induction of labor had differences. Among these factors, estimated fetal body weight by ultrasonography, cervical effacement and augmentation of labor using oxytocin were the most prognostic factors affecting the success of VBAC. In VBAC group, the duration of active-phase, second phase and total duration of labor were 313.5, 36.4 and 350.2 minutes, which were significantly shorter than nulliparas, but longer than multiparas.
CONCLUSION
The trial of labor after cesarean section will decrease repeat operation, if it is performed under exact understanding of successful prognostic factors and the unique time length of labor. It will contribute to increase advantages for mother and economic benefits.

Keyword

VBAC (Vaginal Birth After previous Cesarean section); Successful factors; Complication; Duration of labor

MeSH Terms

Body Weight
Cesarean Section*
Dystocia
Female
Fetal Weight
Gestational Age
Humans
Mothers
Oxytocin
Parity
Parturition*
Pregnancy
Pregnant Women
Retrospective Studies
Trial of Labor
Ultrasonography
Oxytocin