Trial of Magnesium Sulfate Tocolysis Versus Nifedipine Tocolysis in Women With Preterm Labor

Randomized Double-Blinded Trial of Magnesium Sulfate Tocolysis Versus Nifedipine Tocolysis in Women With Preterm Labor Between 24 to 32 6/7 Weeks' Gestation

Primary Hypothesis:

Acute tocolysis (48 hours) using oral nifedipine is more effective than intravenous magnesium sulfate in prolonging pregnancy in women with preterm labor with intact membranes between 24 and 32 6/7 weeks' gestation.

Primary Objective:

To compare the efficacy of oral nifedipine versus IV magnesium sulfate on the rate of preterm delivery at <37 weeks in women with preterm labor between 24 and 32 6/7 weeks gestation.

Secondary Objective:

1. To compare maternal side effects between the two tocolytic agents
2. To compare neonatal morbidities between the two study groups.

Inclusion Criteria:

• Women in preterm labor between 24 to 32 6/7 weeks' gestation with intact membranes with an age range of 15 to 50 years old.

Exclusion Criteria:

• Cervical dilatation of ≥ 6 cm
• Maternal contraindication to tocolysis
• Known fetal anomalies
• Suspected chorioamnionitis
• Nonreassuring fetal heart tracing
• Vaginal bleeding due to placenta previa or abruptio placenta
• Preterm premature rupture of membranes
• Prolapsed membranes
• Human immunodeficiency virus positive
• Multiple gestation
• Patients on procardia within 24 hours of po intake
• Magnesium sulfate tocolysis prior to randomization
• Patient refusal