Effects of antenatal corticosteroids on maternal serum indicators of infection in women at risk for preterm delivery: A randomized trial comparing betamethasone and dexamethasone.

Objective: To compare the effect of betamethasone and dexamethasone on maternal white blood cell (WBC) and differential count, erythrocyte sedimentation rate (ESR), Apgar score, maternal and fetal plasma glucose and length of admission to delivery, gestational age at delivery in women at risk of preterm labor (PTL).

Study Design: Two hundred and forty pregnant women at risk for PTL with intact membranes or preterm premature rupture of the membranes (PPROM) were randomly allocated to receive either two intramuscular injections of 12 mg betamethasone at 24-h intervals or 4 injections of 6 mg dexamethasone at 12-h intervals. Blood tests for WBC and differential count, ESR and fasting plasma glucose were drawn before betamethasone or dexamethasone injection and after injection every 24 h for two days. Pregnancy outcome was assessed as Apgar score, fetal plasma glucose and length of gestation.

Result: In the preterm delivery group with intact membranes, no significant differences were found between the two groups in the maternal serum indicators of infection. The mean gestational age at delivery, 1- and 5-min Apgar score were higher in the dexamethasone group than in the betamethasone group. In the PPROM group, a significant rise in WBC count was occurred (12.4 cells/mm(3) vs. 10.5 cells/mm(3), P < 0.001), none of the other maternal serum indicators of infection and outcome variables showed significant differences between the dexamethasone and betamethasone groups.

Conclusions: Dexamethasone compared to betamethasone significantly increased WBC count in women with PPROM, but in women at risk of PTL with intact membranes none of the maternal serum indicators of infection showed significant differences.