Serum 17 alpha hydroxyprogesterone in normal full term and preterm vs sick preterm and full term newborns in a tertiary hospital.

OBJECTIVES: To determine the variables affecting serum 17 hydroxyprogesterone (17OHP) in neonates born at a tertiary hospital in Mumbai, India.
METHODS: Serum 17OHP was measured in peripheral venous blood between 3rd to 5th day of life by competitive radioimmunoassay and on follow up at 3 mo of age. Serum 17OHP was compared among four groups [full term healthy(FT), full term stressed(FS), preterm healthy(PT), preterm stressed(PS)] by non-parametric tests (Kruskal Wallis (KW) test and Mann- Whitney (MW) test). Pearson's test was used to correlate natural log of serum 17OHP (ln17OHP) with variables like gestational age, birth weight, stress factor, sex, antenatal administration of glucocorticoids to mothers, Apgar score at 5 min and mode of delivery. Linear regression analysis was done using significant variables in Pearson's test to determine best predictors of ln17OHP.
RESULTS: The initial median (number of cases, inter-quartile range) serum 17OHP (ng/ml) for the four groups was as follows; FT 8.4 (33, 6-13); PT 20 (36, 11-29.5); FS 34 (29, 26-45) and PS 58 (24, 40.75-76.5) [total N = 122 newborns, p = 0.001]. Pearson's test showed that gestational age, birth weight, stress factor, Apgar score were negatively correlated with 17OHP whereas stress factor, mode of delivery, use of antenatal steroids in mothers were significantly positively correlated. However, stress factor emerged as the most important significant positive predictor (multiple R = 0.643, P = <0.0001). On follow up at 3 mo age, the median 17OHP (N = 73 newborns) had significantly decreased to normal level.
CONCLUSION: Stress due to neonatal illnesses like meconium aspiration, sepsis, birth asphyxia, etc. significantly elevate serum 17OHP and may lead to false positives in newborn screening for congenital adrenal hyperplasia.