Objective: Do repeat prenatal corticosteroids suppress neonatal cortisol concentrations?
Study design: Randomized controlled trial of women given weekly repeat corticosteroids or saline placebo, while at risk of preterm birth, until 32 weeks' gestation.
Results: Cord serum cortisol concentrations in infants exposed to repeat corticosteroids were similar compared with infants exposed to a single course of corticosteroids (mean difference -26 nmol/L (95% CI -57, 5 nmol/L, P = .10), as were prestress salivary cortisol concentrations on day 3 (median 16.5 vs 15.3 nmol/L, P = .96). The adrenal response to a stressor on day 3 was lower in the repeat corticosteroid group compared with the single course group (median 11.9 vs 21.4 nmol/L, P = .02). Cortisol concentrations were lower in the repeat corticosteroid group on day 7 (median 11.7 vs 18.2 nmol/L, P = .04), but not on days 14 and 21.
Conclusion: The short- or long-term clinical impact, if any, of these changes in adrenal function needs to be determined.