The effect of antenatal corticosteroid on incidence of respiratory distress syndrome according to maternal body mass index

Abstract

ObjectiveTo investigate the effects of antenatal corticosteroid (ACS) on incidence of neonatal respiratory distress syndrome (RDS) according to maternal body mass index (BMI). MethodsWe retrospectively reviewed the medical records of 715 singleton pregnant women who delivered between 24+0 and 34+0 weeks of gestation, from January 1996 to December 2006. Subjects were categorized into three groups according to ACS exposure: a nonuser group (n = 244), a single-course group (n = 377) and a multiple-course group (n = 94). Subjects were re-categorized into three groups according to maternal BMI at admission: group 1 (BMI < 23.0 kg/m 2 , n = 234), group 2 (BMI 23.0-24.9 kg/m 2 , n = 166) and group 3 (BMI ≥ 25.0 kg/m 2 , n = 315). Univariate and multiple logistic regression analyses were used for the statistical analysis. ResultsOverall, the incidence of RDS was signifi cantly lower in ACS-user groups than the non-user group, with lowest incidence in the multiple-course group (non-user vs. single-course vs. multiple-course: 44.3% vs. 41.1% vs. 11.7%, P < 0.001). The incidence of RDS was not different among the three BMI groups. Multiple logistic regression analysis showed that single-and multiple-course of ACS was signifi cantly associated with reduced incidence of RDS: single-course, odds ratio (OR) 0.593, 95% confi dence interval (CI) 0.373, 0.942; multiple-course, OR 0.085, 95% CI 0.034, 0.213. However, maternal BMI was not associated with reduced incidence of RDS with different ACS-courses (P for interaction = 0.690). ConclusionACS therapy, especially when multiple-course was used, was signifi cantly associated with reduced incidence of RDS, but maternal BMI did not infl uence its effectiveness.