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. If shown to reduce the need for respiratory support and thus to decrease the rate of special care nursery admissions and improve short-term outcomes, the public health and economic impact will be considerate.This protocol describes a randomized placebo controlled trial to evaluate whether antenatal corticosteroids can decrease the rate of neonatal respiratory support, thus decreasing the rate of neonatal intensive care unit (NICU) admissions and improving short-term outcomes in the late preterm infant.~Two follow-up studies will be conducted concurrently. The first follow-up study will examine if the positive effects of betamethasone on lung function will persist in children at 6 years of age of mothers randomized to betamethasone with an expected late preterm delivery. Neonatal respiratory morbidity is associated with an increased risk of adverse childhood respiratory disease. Thus it is quite plausible that the effect of betamethasone, in reducing neonatal morbidity, particularly TTN, will translate into improved respiratory morbidity in early childhood.The primary outcome is childhood respiratory disease defined by a composite outcome of abnormal pulmonary function test (PFT) measured by spirometry, physician diagnosis of asthma, or other respiratory illnesses with medication.~The second follow-up study will examine whether late preterm antenatal betamethasone treatment is associated with long-term neurocognitive functioning, and whether there are any long-term consequences of what is believed to be transient neonatal hypoglycemia. Cognitive function will be measured by the Differential Ability Scales 2nd Edition (DAS-II) core components of the general conceptual ability (GCA) that includes verbal ability, non-verbal reasoning ability and spatial ability. The primary outcome is defined as a GCA score of <85 (1 standard deviation below the mean) at 6 years of age or greater.
This 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. 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