Evaluation of Shapes of Uterine Contractions with Oxytocin in the Active Phase of Labor

About 50% of cesarean sections are performed because of abnormal development of first stage، therefore، delivery and its control is very important nowadays. For induction or augmentation of labor، oxytocin infusion is widely used in modern obstetric. Since the contraction shape varies by cephalo-pelvic disproportion، this study was conducted to evaluate the shape of uterine contractions with oxytocin in the active phase of labor. In this ‍Cohort study 100 nulliparous women with singleton pregnancy and cephalic presentation was monitored in dilation 3-4 cm for 30 minutes. In order to precede labor، oxytocin was prescribed to 53 women. Finally، the pattern of contractions was recorded in 10-8 cm cervical dilation for 30 minutes. The ratio of spending time of contraction from peak to baseline (F: Fall) and vice versa (R: Rise) in two phases of beginning and end of the first stage of labor in two groups (with and without prescription of Oxytocin) was calculated and compared. Data were analyzed by using SPSS statistical software version 11. 5، paired T-test، independent T-test، and chi-square. P value less than 0. 05 was considered statistically significant. The ratio of F and R was 1. 164±0. 203 and 1. 150±0. 223 at the beginning and the end of labor in oxytocin received group. The F: R ratio was 1. 161±0. 203 and 1. 091±1. 161±0. 214 at the beginning and the end of labor in the other group. No statistically significant difference was observed in the ratio of F and R between with and without oxytocin groups. Using Oxytocin for augmentation of uterine contractions does not change the shape of the uterine contractions.