NEONATAL EFFECTS AND SERUM CORTISOL-LEVELS AFTER MULTIPLE COURSES OF MATERNAL CORTICOSTEROIDS

Objective: To determine the effects of multiple courses of maternal be tamethasone for fetal lung maturation on neonatal serum cortisol level s and clinical Gushing syndrome. Methods: Seventy-nine mother-infant p airs delivered between 24 and 36 weeks' gestation were enrolled in the study. They were grouped according to the number of courses of betame thasone received between 24 and 34 weeks' gestation for fetal lung mat uration: those receiving no courses, one course, and two or more cours es. Physical examinations were performed and serum glucose, electrolyt e, and cortisol levels were measured on days 1 and 3 of life. Results: For those receiving multiple courses of betamethasone (n = 43), the m ean (+/- standard error of the mean [SEM]) number of courses was 5.3 /- 0.4, with a mean (+/-SEM) total dose of 125.0 +/- 10.7 mg. No neona tes had findings suggestive of Gushing syndrome. Day 1 cortisol levels (pooled mean +/- SEM) were 12.6 +/- 2.4, 5.3 +/- 3.2, and 4.4 +/- 1.8 mu g/dL in those receiving no courses, one course, and two or more co urses, respectively (P = .03; no courses versus two or more courses, P = .03), but the differences were not significant when corrected for m ultiple variables. Differences among day 3 cortisol levels (pooled mea n a SEM) were not significant: 8.3 +/- 1.6, 5.8 +/- 1.4, and 5.8 +/- 0 .9 mu g/dL in those receiving no courses, one course, and two or more courses, respectively. None of the neonates in the group receiving no courses of betamethasone had day 1 cortisol levels lower than normal, whereas 22% and 11% of the neonates receiving one and two or more cour ses, respectively, had day 1 levels lower than normal. On day 3, 15% o f those receiving one course and 10% of those receiving two or more co urses had serum cortisol levels lower than normal, whereas none of tho se who received no courses had a low cortisol level. Multivariate regr ession analysis could show no association between the number of course s or total dose of betamethasone and the day 1 or day 3 cortisol value s. The day 1 cortisol level (log(10)) was most associated with the sev erity of respiratory distress syndrome (RDS) and day 3 cortisol level (log(10)) with race and severity of RDS. Only in neonates with absent or mild RDS did number of courses correlate with day 3 cortisol levels (log(10)), but this was a positive correlation. Conclusion: Serum cor tisol levels either were independent of the number of courses or total dose of corticosteroids given or, in a subpopulation, were associated with increasing levels with increasing doses, suggesting that there i s no suppressive effect with repeated dosing. (C) 1997 by The American College of Obstetricians and Gynecologists.