Short -Term Antenatal Corticosteroid Increases Risk of Respiratory Morbidity in Late Preterm Infants:(TJPS-2021-0012.R1))

Background/Aim: Although antenatal corticosteroid (ANCS) is beneficial for preventing respiratory distress in preterm infants, the effect of ANCS on late preterm infants (LPI) is still unknown. This study aimed at investigating the effect of ANCS on respiratory morbidity of LPI. Materials and Methods: In matched cohort study, LPI of mothers who received ANCS (ANCS group) at 24-34 weeks of GA were matched with LPI of no ANCS (non-ANCS group) by gestational age and birth weight. Results: During 2 years, the ANCS group was 10.6% (191/1,810) in LPI and only 177 neonates met the criteria for inclusion and were ANCS group. The mean gestational age was 34.6 ± 0.7 weeks in both groups. Birth weights were 2270 ± 405 grams and 2265 ± 401 grams in ANCS and non-ANCS groups, respectively. Of the 177 infants whose mothers received ANCS, overall respiratory morbidities were 31.6% comparing to 30.5% in non-steroid group. Although decrease trend toward of RDS (4% vs 8.5%, p = 0.07) and surfactant administration (3.4% vs 6.2%, p = 0.21) was observed in steroid group, administration of steroid < 24 h before gestation significantly increase RDS compared with non-treatment (33.3% vs 8.5%, p = 0.04). Conclusions: ANCS did not decrease risk of respiratory morbidity. Nevertheless, treatment with ANCS for short period (< 24 h) may increase RDS in LPI.