Objective: To examine the consequences of antenatal betamethasone (AB) exposure on postnatal stress regulation.
Study design: Fourteen AB exposed infants born at 28-30 weeks' gestation were assessed in the NICU during postnatal week 1 and at 34 weeks postconception. Nine infants born at 34 weeks gestation without AB treatment were evaluated as a postconceptional age comparison group. Salivary cortisol, heart rate, and behavior were measured at baseline and in response to a heelstick blood draw.
Results: Repeated measures ANOVAs revealed that both groups displayed an increase in heart rate and behavioral distress in response to the stressor. The cortisol response, however, was blunted in AB-treated infants at both assessments.
Conclusion: AB treatment has consequences for hypothalamic-pituitary-adrenal (HPA) axis regulation that persist for at least four to six weeks after birth, indicating that studies of long-term effects are warranted.