The incidences of maternal obesity and obesity-related maternal, fetal and neonatal complications have increased considerably. Obese people may have lower, normal or increased fat mass independent from their body mass index. We aimed to investigate the relationships between antenatal steroid therapy and maternal body fat ratio for the risk of Respiratory distress syndrome (RDS) in preterm infants. Pregnant women and their newborn infants between 24-34 weeks of gestation, who received a full course of antenatal steroid therapy were included in the study. Mother`s body weight, body mass ındex (BMI), and body compositions (muscle, fat, water) were calculated using the bioelectrical impedance method 5 days after giving birth. Neonatal characteristics and respiratory outcomes were noted. A total of 42 mothers and their single premature infants were included in the study. Nineteen (45.2%) infants developed RDS (Group 1) while 23 (54.8%) infants did not develop RDS (Group 2). The mean body fat mass (kg), fat ratio (%), truncal fat mass (kg), and truncal fat ratio (%) were statistically significantly higher in Group 1 than in Group 2. The incidence of RDS was significantly higher in the group of mothers with a body fat ratio > 30.0% (n=15/24, 62.5%) when compared with the group of mothers with a body fat ratio ≤ 30% (n=4/18, 22.2%) (p=0.013). Maternal adipose tissue plays an important role and should be taken into consideration especially in obese women, before giving antenatal steroids to achieve positive effects of the therapy in preterm infants.

Keywords: RDS, antenatal steroid, maternal adipose tissue, newborn, premature, respiratory distress syndrome