ESPE Abstracts

Background and aims: The interpretation of serum 17α-hydroxyprogesterone (17OHP) results is difficult as age-related pediatric reference intervals are scant. The aim of this study is to determine the reference intervals for serum 17OHP according to sex and age groups in newborns. We also aimed to establish reference intervals for right and left adrenal gland sizes, and to evaluate the relation with adrenal size and serum 17OHP concentrations in newborns.

Methods: Healthy newborns (n=142) were enrolled and divided into two groups. Group 1 included newborns between 4 and 7 days of age and Group 2 included newborns between 26 and 30 days of age. Serum 17OHP concentration was measured in the morning. The right and left adrenal glands’ width, length, and depth were measured by ultrasonography and the volumes were calculated. The statistical analyses were performed using SPSS.

Results: The clinical characteristics, serum 17OHP concentrations, and the sizes of left adrenal gland measured by ultrasonography of the male and female newborns were similar. Volume of right adrenal gland was smaller in girls than that of boys in Group 1 (P<0.05). Percentiles for serum 17OHP concentration and the sizes of bilateral adrenal gland by ultrasonography according to age groups were obtained. There was a significant decrease in adrenal sizes at the fourth week of life in both girls and boys. There was no statistically significant correlation between serum 17OHP concentration and adrenal sizes in both sex- and age groups (P>0.05).

Conclusion: It is important to distinguish between diffuse hyperplasia or hypoplasia and normal gland to diagnose congenital adrenal disorders. On the other hand, little is known regarding age and sex-appropriate reference intervals for serum 17OHP during newborn period. To our knowledge, this is the first study which was reported sex-related 17OHP reference intervals combined with bilateral adrenal sizes by US in newborns. Our reference intervals for serum 17OHP and adrenal sizes may improve clinical practice for newborns.