Keywords:Pregnant , Preterm Birth
The rate of preterm birth has steadily increased in the United States over the past 10 years. This increase is driven in part by the rising rate of late preterm birth, defined as those births occurring between 34 and 36 weeks. Late preterm infants experience a higher rate of readmission than their term counterparts, and these infants are more likely to suffer complications such as respiratory distress, kernicterus, feeding difficulties, and hypoglycemia. Late preterm infants also have a higher mortality for all causes when compared to term infants. The use of antenatal corticosteroids has been shown to be beneficial in women at risk for preterm delivery prior to 34 weeks but has not been evaluated in those likely to deliver in the late preterm period.
This study is a randomized placebo controlled trial to evaluate whether antenatal corticosteroids can decrease the rate of neonatal respiratory support, thus decreasing the rate of NICU admissions and improving short-term outcomes in the late preterm infant.
Principle Investigator: Michael Varner
Principle Department: Maternal-Fetal Medicine
1. Singleton Pregnancy. A twin pregnancy reduced to singleton (either spontaneously or therapeutically) before 14 weeks 0 days by project gestational age is acceptable.
2. Gestational age at randomization between 34 weeks 0 days and 36 weeks 5 days confirmed by study criteria
3. High probability of delivery in the late preterm period (any one of the following):
a) Membrane rupture as defined by the occurrence of any two of the following:
• pooling of fluid in the vaginal vault
• positive Nitrazine test
• ferning of vaginal fluid
or any one of the following:
• indigo carmine pooling in the vagina after amnioinfusion
• visible leakage of amniotic fluid from the cervix
b) Preterm labor with intact membranes. Preterm labor is defined as at least 6 regular uterine contractions in 60 minutes and at least one of the following:
• cervix greater than or equal to 3cm dilated
• at least 75% effaced
c) Delivery expected by induction of labor or cesarean section in no less than 24 hours and no more than 7 days, as deemed necessary by the provider. An induction must be scheduled to start by 36 weeks 5 days at the latest, whereas a cesarean delivery must be scheduled by 36 weeks 6 days at the latest. The planned delivery may be for any indication, such as the following:
• prior myomectomy
• prior classical cesarean
• nonreassuring fetal heart rate tracing warranting delivery
• placenta previa
1. Any prior antenatal corticosteroid course during the current pregnancy because of potential contamination of the placebo group
2. Systemic corticosteroid administration during the current pregnancy because of potential contamination of the placebo group
3. Twin gestation reduced to a singleton gestation at or after 14 weeks 0 days by project gestational age either spontaneously or therapeutically
4. Fetal demise, or known major fetal anomaly, including cardiac anomaly and hydrops
5. Maternal contraindication to betamethasone: hypersensitivity reaction to any components of the medication, idiopathic thrombocytopenic purpura, systemic fungal infection in case of exacerbation by betamethasone, use of amphotericin B due to the possibility of heart failure with concomitant betamethasone
6. Pregestational diabetes
7. Delivery expected within 12 hours of randomization, because of insufficient time for corticosteroids to confer benefit, including any of the following:
a) Ruptured membranes with cervical dilation ≥ 3cm or with more than 6 contractions per hour (or both) unless pitocin is deferred for at least 12 hours.
c) Cervical dilation ≥ 8 cm
d) Evidence of non-reassuring fetal status requiring immediate delivery
8. Participation in another interventional study that influences neonatal morbidity or mortality
9. Participation in this trial in a previous pregnancy
10. Delivery at a non-network hospital
11. At 36 weeks 0 days to 36 weeks 5 days and quota for 36 weeks already met. To ensure that there is an adequate proportion of women presenting at 34 to 35 weeks of gestation, enrollment will be restricted so that no more than 50% of the women in the trial present at 36 weeks.