Comparison of the Effect of Oral Dydrogesterone with Oral Nifedipine on the Treatment of Threatened Preterm Labor: A Randomized Controlled Trial

Background: Determining the most effective treatment for women at risk of preterm labor is crucial in reducing potential complications and neonatal mortality. This study aimed to compare the effects of two oral medications, Dydrogesterone and nifedipine, on managing preterm labor in pregnant women admitted with threatened preterm labor. Objectives: The trial aimed to compare the efficacy of Dydrogesterone versus nifedipine in preventing preterm labor. Methods: In this randomized controlled clinical trial, 54 pregnant women aged 18 to 45 years, with a gestational age of 26 to 34 weeks and at risk of preterm labor, were randomly assigned to receive either 40 mg oral Dydrogesterone or a standard dose of nifedipine (10 mg for the first dose) as a tocolytic. Key maternal and neonatal outcomes, including the interval between intervention and delivery, delivery type, neonatal intensive care unit (NICU) admission, NICU stay duration, and Bishop scores, were evaluated and compared between the two study groups. Results: The mean age of participants was 27.78 ± 2.53 years in the nifedipine group and 27.67 ± 2.53 years in the Dydrogesterone group. There were no significant differences (P > 0.05) between the two groups in baseline characteristics. The mean NICU stay in the Dydrogesterone group (2.3 ± 0.5 days) was significantly shorter than in the nifedipine group (4.6 ± 0.5 days) (P = 0.001). Although the frequency of gestational age at delivery, NICU admission, the interval between intervention and delivery, and repeated preterm labor were lower in the Dydrogesterone group, the differences between the groups were not statistically significant (P > 0.05). Conclusions: The findings suggest that Dydrogesterone is effective in treating preterm labor. Both drugs prevented preterm labor; however, nifedipine, despite being a standard treatment, has potential side effects and may not be suitable for all patients. These results indicate that Dydrogesterone, with fewer side effects, could be an alternative for patients who cannot use nifedipine. Further studies with larger sample sizes are needed to confirm or refute this finding.