Comparative Study of Vaginal versus Intramuscular Progesterone in the Prevention of Preterm Delivery: A Randomized Clinical Trial

BACKGROUND: Preterm birth is a worldwide health concern due to its various negative consequences. Therefore, the prevention of preterm birth is a top priority for healthcare systems in all countries. OBJECTIVE: To compare the effectiveness of vaginal versus intramuscular progesterone in the prevention of preterm delivery. METHODS: This randomized clinical trial was conducted at Shahid Sadoughi Hospital in Yazd, Iran, from November 21, 2012 to January 20, 2015. Seventy-eight pregnant women with singleton pregnancy and one risk factor of preterm delivery were included in the study. The subjects were assigned randomly to two groups, with group one receiving Cyclogest and group two receiving 17-α hydroxyprogesterone caproate. Subsequently, we analyzed drug complications during pregnancy, delivery time, neonatal outcomes, and patients’ satisfaction among the two groups. The data were analyzed using SPSS version 16. We used descriptive statistics, chi-squared, t-test, and ANOVA for the analyses of primary and secondary outcomes. RESULTS: Among the 39 births in group one, 33.3% occurred preterm, and, among the 39 births in group two, 30.7% occurred preterm (< 37 weeks). The mean gestational ages at delivery in groups 1 and 2 were 37.07 ± 2.23 and 36.81 ± 2.77 weeks, respectively (p = 0.765). Other variables were not significantly different between the two groups, including birth weight (p = 0.745), Apgar scores for the first and fifth minutes (p = 0.574, 0.630), length of stay in the neonatal intensive care unit (NICU) when the newborns needed hospitalization (p = 0.358), and the patients’ satisfaction with the drugs that were used (p = 0.615). CONCLUSIONS: In this study, vaginal progesterone and intramuscular progesterone had the same levels of effectiveness, safety and acceptance by patients in the prevention of preterm delivery. Therefore, both can be used for this purpose in clinical practices, but more studies are needed.