Nifedipine for Acute Tocolysis of Preterm Labor

Nifedipine for Acute Tocolysis of Preterm Labor

The purpose of this study is to determine if nifedipine treatment of women in preterm labor receiving corticosteroids results in postponement of delivery when compared to placebo.

Inclusion Criteria:

• Between 16 and 44 years of age inclusive
• Singleton pregnancy
• Intact membranes
• Between 28-0/7 weeks and 33-6/7 weeks' gestation inclusive
• Reported or documented uterine activity
• Cervical dilation between 2 cm and 4 cm inclusive

Exclusion Criteria:

• Multifetal gestation
• Less than 28 weeks' gestation
• 34 or more weeks' gestation
• Ruptured membranes
• More than 4 cm dilated
• Previously received a course of corticosteroids for fetal lung maturation
• Oligohydramnios
• Fetal growth restriction
• Chorioamnionitis or temperature of at least 38.0 degrees Celsius
• Fetal death
• Preeclampsia
• Suspected placental abruption or placenta previa
• Lethal fetal malformation or amniotic fluid index at least 35
• Systolic BP < 90 mmHg or diastolic BP < 50 mmHg
• Baseline tachycardia (pulse >120 after 2 consecutive measurements 30 minutes apart)
• Chronic hypertension treated with antihypertensives in pregnancy
• Seizure disorder or HIV
• Maternal allergy to nifedipine
• Known maternal cardiac disease
• Women who have received progesterone therapy in the second or third trimester for prevention of preterm birth