Intravenous magnesium sulfate and isoxsuprine for arrest of preterm labor: A comparative study

Abstract

Background: Despite advances in obstetrics and neonatal care, the rate of incidence of preterm births continues to increase. Use of tocolytic agents such as magnesium sulfate and isoxsuprine could help in arresting preterm labor. Considering the paucity in studies comparing these two agents, a comparative analysis is obligatory. Objective: The objective of the study was to compare the safety, efficacy, and success rate of magnesium sulfate and isoxsuprine in the arrest of preterm labor. Methodology: Eighty-two antenatal women belonging to 28–37 weeks of gestational age, with regular uterine contractions, cervical dilatation (≤3 cm), and <50% cervical effacement admitted with complaints of preterm labor pain were randomly allocated into two groups with 41 participants in each group. Group 1 received 40 mg isoxsuprine for 24 h and later, isoxsuprine capsule 40 mg was given orally twice a day for 7 days, and Group 2 received 4 g magnesium sulfate for 12 h if uterine quiescence was achieved by the end of 2 h. Demographic data, medical history, and clinical data were collected. The outcome variables measured included side effects and the success rate (effacement% and cervical dilatation). Statistical analysis was performed using R software (Version 3.6.0). Results: The majority of the patients in both the groups with <25% effacement had successful tocolysis (P > 0.05). In Group 2, patients with <1 cm of cervical dilatation had successful tocolysis compared to Group 1 (P < 0.05). A highly significant association was observed between the percentage of effacement and cervical dilation, successful tocolysis (P < 0.001). Tachycardia and hypertension were observed more in Group 1, whereas nausea and vomiting were common in Group 2. The overall success rate was better in Group 2 (85.37%) compared to Group 1 (65.85%). Conclusion: Magnesium sulfate was slightly more effective in arresting preterm labor with lesser side effects as compared to isoxsuprine.