Continuous 24‐hour secretion of growth hormone during late pregnancy

Abstract

A dramatic change in growth hormone secretion was demonstrated during the 3rd trimester of human pregnancy, when compared with the non-pregnant state. The pulsatile pattern, with intermittent high peaks, and low or undetectable levels between peaks, characteristic of normal men and non-pregnant women, was completely abolished. All the 10 pregnant women investigated had the same stable basal circulating growth hormone concentration. Values were in the range 6-10 mU/l and there was no evidence of pulsatile activity. Previously, in animal experiments, a continuous secretion of growth hormone has been shown to 'feminize' hepatic steroid metabolism, hepatic prolactin receptors, hepatic sulphatase activity and to stimulate pregnancy protein synthesis. The same biological principle could be valid also during human pregnancy and be related to maternal metabolic adjustment.

Plasma Profiles of Growth Hormone, Prolactin and Insulin-like Growth Factor-I during Gestation, Lactation and the Neonatal Period in Goats.

“…However, serum GH levels in humans did not increase, or rather the GH levels declined during the second half of pregnancy [31][32][33][34][35][36][37][38]. No obvious changes in GH profiles among each month of gestation were observed in the goats of the present study, and these GH profiles for goats during the gestation period seem to be similar to those of humans.…”

Growth hormone binding protein and maternal body mass index in relation to placental growth hormone and insulin requirements during pregnancy in type 1 diabetic women

“…Free PGH is expected to be the biologically active form of PGH. In contrast to GH, PGH displays a more continuous secretory profile [7,8] and this allows for a sustained effect of PGH on peripheral tissues. Furthermore, GHBP levels decline during late gestation in normal pregnancies [9], thereby further interfering in the balance between free and bound PGH.…”

Serum Levels and Molecular Sizes of Growth Hormone during Pregnancy in Relation to Levels of Lactogens, Insulin-Like Growth Factor I and Insulin-Like Growth Factor Binding Protein-1

“…By introducing monoclonal an tibodies (Mabs) against GH, which do not react with PL, several authors have been able to show a decline in GH throughout pregnancy and low levels of serum GH in the third trimester [1,2]. Furthermore, the pulsatile pattern of the the GH secretion seen in nonpregnant individuals has been reported to disappear in the latter part of preg nancy [3].…”