Effect of antenatal betamethasone treatment on stress physiology in healthy neonates
Introduction: There is evidence that antenatal corticosteroid treatment of women at risk for premature delivery may have a lasting impact on the functioning of the hypothalamo-pituitary-adrenal (HPA) axis in the infant. We analyzed postnatal stress regulation in healthy neonates that received antenatal betamethasone treatment.
Methods: Salivary cortisol and cortisone production in 15 healthy neonates born >34 weeks of gestation with antenatal betamethasone (2 doses of 12mg i.v., 24h apart) treatment was analyzed. Baseline levels and stress response following the heel-prick test as stressful event were compared with 30 untreated neonates.
Results: Mean gestational age at birth was similar (266 vs. 270 days, respectively) and mean birth-weight did not differ between treatment and control group (3150g (55. perc.) vs. 3152g (49. perc), respectively). Mean baseline levels for cortisol and cortisone were not significantly different between the treatment- (1.9 ng/ml and 13.8 ng/ml, respectively) and the control group (2.1 ng/ml and 13.5 ng/ml, respectively) (n.s.). Both groups exhibited a similar physiological increase in cortisol and cortisone release 20 minutes after the stress induction (3.6 ng/ml and 17.7 ng/ml for treatment- vs. 3.3 ng/ml and 17.6 ng/ml for control group) revealing no statistical significant difference in stress response patterns.
Conclusion: Antenatal betamethasone treatment in pregnancies at risk for preterm delivery before 34 weeks of gestation appears not to alter the physiological activity of the HPA axis in healthy neonates.