Immature adrenal steroidogenesis in preterm infants

Area of Science:

• Neonatal endocrinology
• Biochemical analysis
• Pediatric screening

Background:

• Congenital adrenal hyperplasia (CAH) screening in preterm infants often results in false positives.
• Radioimmunoassay (RIA) studies show elevated 17 alpha-hydroxyprogesterone in critically ill preterm infants, but cross-reactivity issues limit RIA reliability.
• Accurate assessment of adrenal steroidogenesis is crucial for preterm infants.

Purpose of the Study:

• To evaluate adrenal steroidogenesis in preterm infants using a more reliable method.
• To investigate the reliability of steroid level measurements in preterm neonates.
• To identify appropriate monitoring strategies for preterm infants at risk for CAH.

Main Methods:

• Utilized reversed-phase high-performance liquid chromatography (RP-HPLC) for steroid analysis.
• Evaluated adrenal steroidogenesis in 33 preterm infants (<32 weeks' gestation).
• Measured levels of 17 alpha-hydroxyprogesterone, 11-deoxycortisol, corticosterone, cortisol, and cortisone.

Main Results:

• Intermediate steroids (17 alpha-hydroxyprogesterone, 11-deoxycortisol, corticosterone) were temporarily detectable around 29 weeks' equivalent gestational age in 27/33 infants.
• Cortisol and cortisone levels were significantly decreased in 4/16 infants whose mothers received prenatal steroids.
• Findings suggest decreased activity of 21-hydroxylase, 11 beta-hydroxylase, and 18-hydroxylase around 29 weeks' gestational age.

Conclusions:

• RP-HPLC provides a reliable method for assessing adrenal steroidogenesis in preterm infants.
• Decreased hydroxylase activities may explain altered steroid profiles in preterm neonates.
• Careful monitoring of steroid levels using RP-HPLC is recommended for preterm infants with elevated intermediates or maternal steroid exposure.