The effectivity of balloon catheter for labor induction in post-term pregnancy

To determine the effectiveness of balloon catheter compared with intravaginal misoprostol in inducing labor of post-term pregnancy, Retrospective cohort have been performed in DR Sardjito Hospital, Yogyakarta. Data were taken from medical record of patients receiving balloon catheter and intravaginal misoprostol for inducing labor between the period of January 1998 to January 2001. Balloon catheter were inserted thoroughly the cervical canal beyond the internal os and was filled with 75 ml normal saline. Misoprostol 50 mcg was inserted intravaginally to the posterior fornix every 6 hours. As much as 110 cases were including criteria for ballooning and 105 cases for misoprostol. Induction was successful if dilatation reached 3-4 cm or balloons were expelled. The expected outcome were the success rate of induction and the interval between insertion to active phase. Data were analysis using SPSS version 10.0. Chi-square, Nests, Mantel Haenszel, and logistic regression were used as statistical analysis. There were 110 cases of balloons and 105 cases of misoprostol meeting study criteria. The success rate of balloon and misoprostol were 89.09% and 82.85% respectively, which is neither clinically nor statistically different (p=0.19). Interval between insertion to active phase in the balloon and misoprostol group were 10.41 + 6.60 hours and 10.60 + 6.67 hours respectively, which neither clinically nor statistically different (p=0.84). In the nullipara the success rate of balloon catheter was 2.32 folds higher compared with misoprostole. Logistic regression model showed that the success rate of induction was influenced by age of the mother. Interval between insertion to active phase for group of Bishop score < 4 was 10.90 + 6.75 hours compared with 6.28 + 3.03 hours for group of Bishop score > 4, and it was highly significant (p=0.005). Balloon catheter was the same effective as misoprostol to induce labor in post-term pregnancy. Balloon catheter was more effective in nulli para and interval fron insertion to active phase was influenced by Bishop score.