Magnesium Sulfate versus HCG (Human Chorionic Gonadotropin) in Suppression of Preterm Labor

Introduction: Preterm labor is defined as delivery before 37completed weeks of pregnancy. Since 10% of total labors are preterm and 70% of infants’ mortality is due to this problem, preterm labor is an important problem in obstetrics, midwifery and pediatrics. So that different treatments have been employed in order to suppress preterm labor from several years ago. Magnesium sulfate is often used as a first - line in suppressing of preterm labor, although its maternal and neonatal side effects are common, in best of conditions only 24-48 hours delays of labor, and randomized clinical trial studies have shown that in suppression of preterm labor it is as effective as placebo. On the other hand because of known ability of Human Chorionic Gonadotropin (HCG) in suppression of contractions in muscles detached from human myometer (in vitro), and safety of this drug in pregnancy, we take a decision that compare the ability of Magnesium Sulfate with HCG in suppression of preterm labor.

Materials and Methods: In this clinical trial study, 64 cases were chosen from pregnant women between the 24-34 weeks of pregnancy who were suffering from preterm contractions of uterus with intact amniotic sac and cervical dilatation of less than 4 cm. These women had referred to obstetric ward of Ali-Ebne-Abitalib Hospital, Zahedan, Iran during the years of 2004-6 and randomly were divided into two equal groups (32 cases in each group) In first group primarily 4 grams of Magnesium Sulfate (1 gram per minute) infused and then 2 grams per hour was continued. Whereas, in second group HCG was injected firstly 5000 units intramuscularly and then infused 20 units per minute. Treatments in both groups were continued to 12 hours after uterine contractions stoppage, during the treatments therapeutic effects as well as maternal conditions and complains were recorded in both groups. The results were analyzed by Chi square and T test with SPSS software, differentiation was regarded as significant if P value <0.05.

Results: The average duration between initiation of treatments and suppression of contractions of uterus in the first group who had received Magnesium Sulfate was 2.90.5 hours, while in the second group that had received HCG was 3.140.25 hours, so that differentiation of two groups from this point was non-significant (pv = 0.132). Average rate of labor within 48 hours after beginning of treatment, in the first group was 13% while in second group it was 15% (pv = 0.223), so that there was not significant differentiation between two group from this point too. Whereas, frequency of patients complaints due to side effects of medications in the first group was 100% while in second group was zero (pv <0.0001) which was significant.

Conclusion: HCG and Magnesium Sulfate in suppression of preterm labor have the same efficacy but since HCG has not any maternal and neonatal side effects, it is a good alternative in suppression of preterm labor.