Urinary Growth-Hormone In Neonatal-Period In Infants Of Diabetic Mothers

Infants of diabetic mothers (IDM) are suggested to have elevated plasma levels of growth hormone (GH) in the early neonatal period. This can be caused by increased secretion, decreased elimination or excretion. As secretion and elimination studies are difficult to perform in this age-group, we have studied the excretion of urinary HGH to elucidate this unexplained phenomenon. Urinary GH was studied with the method of Hanssen in 10 newborns (IDM). Simultaneously 10 infants of normal mothers (INM) were examined within the first 3 days of life. The samples obtained were randomized before analysis. Results: Day 1: No significant difference between IDM and INM could be demonstrated. Day 2: Significantly higher excretion of GH was found in IDM. Day 3: Extremely high excretion of GH: 1573ng/100 ml/m2 (INM: 92ng/100 ml/m2) was seen. Even though higher diuresis was found in IDM on day 3, the total excretion of GH in a given volume of urine was increased in IDM. The findings are compatible with an increased secretion of GH in the early neonatal period but also with an increased renal clearance from the second day of life.