Induction of labor: comparison of a cohort with uterine scar from previous cesarean section vs. a cohort with intact uterus.
OBJECTIVE
To compare the risk of uterine rupture between a cohort of women with previous low-transverse cesarean section (CS) and a cohort with intact uterus.


METHODS
All women with a singleton pregnancy and previous low-transverse CS requiring induction of labor from January 1, 1992 to December 30, 2001 (n = 310) were compared with a cohort of women with intact uterus undergoing induction of labor during the same study period (n = 5420). Protocols of induction using prostaglandin E2 gel and oxytocin infusion were consistent within groups, but differed between the previous CS and the intact uterus group.


RESULTS
Uterine rupture occurred in 0.3% in the previous CS group vs. 0.03% in the intact uterus group (p = 0.37). Logistic regression analysis showed no significant difference in rate of uterine rupture between the previous CS vs. intact uterus group (p = 0.16) after controlling for maternal age, parity, gestational age at delivery, Bishop score on admission, use of prostaglandin and oxytocin, and birth weight. Our study had adequate power to detect a 0.38% difference in rate of uterine rupture between the two groups (alpha = 0.05, beta = 0.80).


CONCLUSIONS
Induction of labor is not associated with significantly higher rates of uterine rupture among women with previous low-transverse CS compared with women with intact uterus provided a consistent protocol with strict intervention criteria is adopted.
Locatelli
Anna
A
Department of Obstetrics and Gynaecology, University of Milano-Bicocca, Monza, Italy. as.maggio@tin.it
Ghidini
Alessandro
A
Ciriello
Elena
E
Incerti
Maddalena
M
Bonardi
Claudia
C
Regalia
Anna Laura
AL
D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects*; D016015:Logistic Models; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014597:Uterine Rupture / Q000453:epidemiology / Q000209:etiology*; D016064:Vaginal Birth after Cesarean / Q000009:adverse effects*