Evaluation of the effect of progesterone on prevention of preterm delivery and its complications

Preterm delivery is a major cause of prenatal mortality and morbidity in the world and results in increased obstetric and pediatric care costs. The purpose of this study was to evaluate the effects of prophylactic vaginal progesterone in decreasing the rate of preterm delivery and its complications in high risk women. This study included 150 asymptomatic women with high risk singleton pregnancies. The subjects were assigned randomly into two similar groups. One group received 100 mg of prophylactic vaginal progesterone therapy (n=75) daily between the 24th and 34th week of gestation and the other group received no treatment (n=75). The two groups were similar regarding maternal age and preterm delivery risk factors. Uterine contractions were monitored by external tocodynamometer for 60 minutes and in case of true contractions, routine tocolytic drugs were started for the subjects. In some patients, in spite of receiving tocolytic drugs, delivery progressed and the related data were collected. Data were introduced into SPSS software and analyzed by means of chi square, exact Fischer, ManWitney U, and t tests. The results were reported with a confidence level of 95%. The mean gestational age at the time of delivery was higher in the interventional group (38.62 2.08 week vs. 35.88 3.5 week) (P=0.001). Preterm delivery before the 37th week of gestation occurred in 11.6% and 31.9% of the subjects in the progesterone and control groups respectively (P=0.004) and preterm deliveries before the 34th week occurred in 22.2% and 2.9% of the women in the control and progesterone groups respectively (p=0.001). Moreover respiratory distress syndrome, low birth weight, birth weight, need for oxygen, infant apgar,need for mechanical ventilator, and hospitalization in NICU were significantly different between the two groups (P<0.01). prophylactic vaginal progesterone reduced the frequency of uterine contractions which led to decreased rate of preterm delivery in women with high risk factors for preterm delivery.