Benefits of Antenatal Corticosteroid in Infants Delivered before 33 weeks of Gestation after Premature Rupture of Membranes

Koo, Bon Sang; Chung, Ji Youn; Kim, Jong Soo; Kim, So Ra; Lee, Sang Su; Won, Hye Sung; Suh, Dae Shik; Lee, Pil Ryang; Kim, Ahm

Abstract

OBJECTIVE
To evaluate the benefits of maternal corticosteroid therapy in infants delivered before 33 weeks of gestation after premature rupture of membranes (PROM).
METHODS
This retrospective study included the pregnant women complicated by preterm delivery within 32 weeks of gestation after PROM at the Asan Medical Center between 1997 to 1999. Patients were divided into 2 groups according to the gestational age at delivery, i.e., one group who delivered within 28 weeks of gestation and the other group who delivered between 29 and 32 weeks of gestation. Within each group, we evaluated the effect of maternal dexamethasone therapy on the perinatal and neonatal outcomes based on the medical records. Data were analyzed with pearson's chi-square test, Fisher's exact test, and two sample t-test. p<0.05 was considered statistically significant.
RESULTS
One hundred and fifteen pregnancies complicated by preterm delivery within 32 weeks of gestation after premature rupture of membranes were included. Preterm deliveries occurred within 28 weeks of gestation in 48 cases (41.7%) and between 28 and 32 weeks of gestations in 67 cases (58.3%). Antenatal dexamethasone therapy was done in 27 out of 48 mothers (56.3%) who delivered within 28 weeks of gestation and in 47 out of 67 mothers (70.1%) who delivered between 29 and 32 weeks of gestation. Antenatal dexamethasone therapy did not affect the selected perinatal outcome variables (gestational age at delivery, birth weight, Apgar scores, cesarean section rate, and maternal and neonatal WBC counts and serum C-reactive protein concentrations). Incidences of neonatal complications (respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity, and periventricular leukomalacia) between the groups who did and did not received antenatal dexamethasone were not significantly different in pregnancies who delivered within 28 weeks of gestation. However, incidences of respiratory distress syndrome and intraventricular hemorrhage were significantly lower in a group who received antenatal dexamethasone than in a group who did not in pregnancies who delivered between 29 and 32 weeks of gestation (p<0.05).
CONCLUSION
Antenatal corticosteroid therapy may be beneficial to the infants delivered between 29 and 32 weeks of gestation after PROM. However, it may have no therapeutic advantage to the group who delivered within 28 weeks of gestation after PROM.