Antenatal Dexamethasone Treatment Decreases Plasma Catecholamine Levels in Preterm Infants

Abstract

Antenatal corticosteroid therapy (ACT) has many beneficial effects on preterm infants. The cellular mechanisms of action of ACT include beta-adrenergic receptor-mediated cAMP generation. This study investigated the effects of ACT on sympathoadrenal mechanisms during immediate postnatal adaptation of preterm infants. Plasma epinephrine, norepinephrine, 3,4-dihydroxyphenylglycol, and cAMP were measured within 12 h after birth in 103 preterm infants (gestational age 24-36 wk), who were divided into two groups (non-ACT and ACT group) according to whether the mother had received dexamethasone treatment. Infants in the ACT group had significantly lower concentrations of plasma catecholamines than infants in the non-ACT group; plasma epinephrine was 38% lower, and plasma norepinephrine was 20-40% lower in the ACT group, depending on gestational age (r = -0.37 in the non-ACT group and r = -0.28 in the ACT group, p < 0.05). Plasma cAMP concentrations were similar in the two groups. Antihypertensive treatment of the mother was associated with low plasma cAMP (p < 0.001), whereas tocolytic treatment was associated with high plasma cAMP (p = 0.001) of the infant. The results indicate that ACT attenuates the birth-related increase in plasma catecholamines. Still, plasma cAMP levels remain high, which suggests enhanced beta-adrenoceptor signaling after ACT.

Antenatal and Early Postnatal Dexamethasone Treatment Decreases Cortisol Secretion in Preterm Infants

“…At birth, ACT was shown to decrease catecholamine concentrations in these patients [15]. The results suggest that the effect of dexamethasone on catecholamine and cAMP synthesis or secretion is not seen when their high levels at birth have already declined and their crucial impact on immediate neonatal adaptation has passed.…”

“…Glucocorticoids have also been shown to increase β-adrenoceptor-dependent adenosine 3′,5′-cyclic monophosphate (cAMP) generation [14]. In a previous study, we showed that ACT modulates sympathoadrenal activity by suppressing E and NE secretion at birth, while the concentration of cAMP is not changed [15]. Corticosteroid treatment may thus modulate cAMP production either by modifying the secretion of catecholamines, or by affecting the density and function of β-adrenoceptors.…”

Neonatal catecholamine levels and neurodevelopmental outcome: a cohort study

“…There is a theoretical concern that measures to reduce catecholamines, such as opiate sedation, may blunt this adaptive response and lead to higher mortality and morbidity in surviving infants. From clinical studies, however, the reductions in catecholamine levels associated with morphine treatment12 15 and antenatal corticosteroids16 do not appear to be associated with a detrimental effect.…”

Safety of dermatologic drugs used in pregnant patients with psoriasis and other inflammatory skin diseases

“…97-100 Transient alterations of HPA axis function have been found to occur in infants of women who were treated with corticosteroids late in pregnancy. 97,98,[101][102][103][104] Cushing's syndrome with suppression of the HPA axis was reported in one infant whose mother had been treated with 7 courses of betamethasone during pregnancy. 105 In one long-term study, prenatal exposure to a single course of betamethasone late in pregnancy had no clinical effect on cognitive functioning, health-related quality of life, or cardiovascular risk factors in 30-year-old subjects.…”