Human fetal plasma growth hormone prior to the onset of labour. Effects of stress, glucose, arginine and maternal diabetes.

Abstract

Serial plasma growth hormone (GH) concentrations have been estimated in fetuses of normal and diabetic mothers before the onset of labour. The mean initial GH concentration of normal fetuses was 32 ng/ml (range 11–59 ng/ml). The fetuses of diabetic mothers had a higher mean level (47 ng/ml); and in these fetuses, there was an inverse relationship between the initial GH level and the fetal plasma glucose concentration. It is possible that the stress of induction of labour and sampling may have stimulated GH release. Maternal glucose infusion was associated with a fall in fetal GH levels, which was greater in the fetuses of diabetic mothers than in control fetuses. There was a small rise in fetal GH concentration following maternal arginine infusion. These findings suggest both that there are similarities between the control of GH secretion in the human fetus and the adult, and that there are differences between GH responses in the fetuses of normal and diabetic mothers.