Cm. Zelop et al., Uterine rupture during induced or augmented labor in gravid women with oneprior cesarean delivery, AM J OBST G, 181(4), 1999, pp. 882-886
OBJECTIVE: Our purpose was to examine the risk of uterine rupture during in
duction or augmentation of labor in gravid women with 1 prior cesarean deli
very.
STUDY DESIGN: The medical records of all gravid women with history of cesar
ean delivery who attempted a trial of labor during a 12-year period at a si
ngle center were reviewed. The current analysis was limited to women at ter
m with 1 prior cesarean delivery and no other deliveries. The rate of uteri
ne rupture in gravid women within that group undergoing induction was compa
red with that in spontaneously laboring women. The association of oxytocin
induction, oxytocin augmentation, and use of prostaglandin Ee gel with uter
ine rupture was determined. Logistic regression analysis was used to examin
e these associations, with control for confounding factors.
RESULTS: Of 2774 women in the analysis, 2214 had spontaneous onset of labor
and 560 women had labor induced with oxytocin or prostaglandin Ep gel. The
overall rate of rupture among all patients With induction of labor was 2.3
%, in comparison with 0.7% among women with spontaneous labor (P = .001). A
mong 1072 patients receiving oxytocin augmentation, the rate of uterine rup
ture was 1.0%, in comparison with 0.4% in nonaugmented, spontaneously labor
ing patients (P=.1). In a logistic regression model with control for birth
weight, use of epidural, duration of labor, maternal age, year of delivery,
and years since last birth, induction with oxytocin was associated with a
4.6-fold increased risk of uterine rupture compared with no oxytocin use (9
5% confidence interval, 1.5-14.1). In that model, augmentation with oxytoci
n was associated with an odds ratio of 2.3 (95% confidence interval, 0.8-7.
0), and use of prostaglandin E-2 gel was associated with an odds ratio of 3
.2 (95% confidence interval, 0.9-10.9). These differences were not statisti
cally significant.
CONCLUSION: Induction of labor with oxytocin is associated with an increase
d rate of uterine rupture in gravid women with 1 prior uterine scar in comp
arison with the rate in spontaneously laboring women. Although the rate of
uterine rupture was not statistically increased during oxytocin augmentatio
n, use of oxytocin in such cases should proceed with caution.