Early amniotomy - high risk factor for cesarean section

Objective: To evaluate the effect of early amniotomy on mode of delivery an d pregnancy outcome in comparison to a group of patients admitted with prem ature rupture of membranes at term. Study design: The study population cons ists of all women (n=338) whose labor was induced by amniotomy, between the years 1988 to 1995. The comparison group were all women (n=1865) who were admitted with premature rupture of membranes during the same period. Result s: Cesarean section was significantly higher in the amniotomy group than in the comparison group (162 (47.9%) vs. 348 (18.7%), P<0.001). This signific ant difference was noted only for those who did not had a previous cesarean section (106 (42.4%) vs. 224 (13.8%), P<0.001). Non progressive labor duri ng the first stage was threefold higher in the amniotomy group than in the control group (30.8% vs. 10.9%, P<0.001). Abnormal fetal heart rate pattern s were detected during labor in 52 patients (15.4%) of amniotomy group, as compared to 141 cases (7.6%) in the control group (P<0.001). To assess the independent contribution of early amniotomy to having cesarean section in t he present delivery, a multiple logistic model was used. Early amniotomy (o dds ratio [OR] 3.07, 95% confidence interval [CI] 2.36-4.01), as well as a previous cesarean section (OR 5.04, 95% CI 3.90-6.52) and high parity (OR 1 .07, 95% CI 1.03-1.26) were all found as independent risk factors for cesar ean section. Conclusions: Early amniotomy appears to be associated with an increased risk for cesarean section. O 1999 Elsevier Science ireland Ltd. A ll rights reserved.