Fetal Growth and the Function of the Adrenal Cortex in Preterm Infants

Abstract

Small for gestational age preterm infants have a higher risk of neonatal morbidity compared to appropriate for gestational age preterm infants. A diminished adrenal response to stress may be involved in the higher postnatal morbidity. The adrenal cortex response in relation to fetal growth was studied by ACTH stimulation tests in 43 preterm infants (born < or = 32 wk). The cortisol and 17-hydroxyprogesterone (17-OHP) responses to 1 microg/kg ACTH were analyzed in relation to birth weight SD scores (BW-SDS) corrected for gestational age, gender, and parity. BW-SDS was significantly associated with the cortisol and 17-OHP response. Infants with the lowest BW-SDS had the lowest cortisol levels after stimulation. No effect of size at birth was found on the ratio between cortisol and 17-OHP. In addition, basal cortisone levels in a single blood sample were higher in infants with the lowest BW-SDS than in infants with higher BW-SDS, but the ratio between cortisol and cortisone was comparable in the two groups. We conclude that the response of cortisol and 17-OHP to ACTH stimulation in preterm infants is related to fetal growth. The lack of influence of fetal growth on the ratio between cortisol and 17-OHP after ACTH stimulation suggests that the activities of 21- and 11 beta-hydroxylase are not affected. The lower adrenal response to stimulation may be important in neonatal morbidity and possibly the development of disease in later life in growth-restricted preterm infants.

Effect of Single and Multiple Courses of Prenatal Corticosteroids on 17-Hydroxyprogesterone Levels: Implication for Neonatal Screening of Congenital Adrenal Hyperplasia

“…In addition to glucocorticoid treatment, IUGR and RDS were significant independent predictors of blood-spot 17-OHP in multiple regression analysis, in agreement with other studies (11,28,33): positive relationships between birth weight SD score and basal and stimulated blood 17-OHP were recently reported in 43 premature infants with and without growth retardation, suggesting that adrenal function was related to fetal growth in preterm infants (33). The positive influence of RDS on blood 17-OHP has also been previously described in other studies (28) and is usually viewed as a consequence of illness-related stress.…”

Postnatal Diet-Induced Obesity in Rats Upregulates Systemic and Adipose Tissue Glucocorticoid Metabolism During Development and in Adulthood

“…Several mechanisms may be involved for the accelerated maturation of the central components of the HPA axis. It has been suggested that shortage of nutrients is directly responsible for the postnatal decreased adrenal cortex activity associated with intrauterine growth retardation or prematurity with fetal growth inhibition in humans (28). It is conceivable that an excess of nutrients could have per se a stimulatory effect on the maturation of the HPA axis.…”

Impaired adrenocortical function in very low birth weight infants after multiple pregnancies

“…The time at which the samples were obtained might not be the crucial point. SGA (30,31), arterial hypotension (1,8,9), respiratory problems (4) and antenatal exposure to corticosteroids have been reported to affect basal cortisol production in preterm infants (32 -34). The condition has been associated with endocrine dysfunction at the adrenal level or the mechanism might be connected with the inability of the hypothalamus to recognize the stimulatory signal (5,9,34,35).…”