Plasma Human Placental Lactogen Profiles Over 24 Hours in Normal and Diabetic Pregnancy

Abstract

Summary Plasma human placental lactogen (HPL) concentrations have been measured at frequent intervals over 24 hours in 24 normal women, 13 chemical and 13 insulin dependent diabetic patients during the third trimester of pregnancy. Most of the women studied displayed variation in HPL levels during the day, but there was no evidence of a diurnal rhythm, nor significant changes following meals or during the nocturnal fast. The mean plasma HPL concentrations over 24 hours in the chemical and insulin dependent diabetic patients (5·9±SD 1·3 and 5·9±l·7 μg/ml respectively) were greater than those in normal women (5·1·1·2 μg/ml) but this difference was not significant. No significant change in plasma HPL concentrations was observed during a five‐hour oral glucose tolerance test in either the normal or chemical diabetic group. It is suggested that in normal pregnant women HPL does not itself contribute to glucose homeostasis but acts as a ‘regulator’ which alters the actions of certain maternal hormones to achieve a favourable environment for fetal growth.

Growth Hormone-Binding Protein in Plasma Is Inversely Correlated to Placental Lactogen and Augmented with Increasing Body Mass Index in Healthy Pregnant Women and Women with Gestational Diabetes mellitus

“…4). 148 Luthman/Stock/Wemer/Bremme GH and GHBP during Pregnancy Pituitary GH and PL in plasma were inversely corre lated in all women supporting the hypothesis that PL exerts an inhibitory effect on pituitary GH [28], In con trast, PL was positively correlated to PRL in the GDM group and in the two groups together. Furthermore, PL was inversely correlated to GHBP in all women.…”

“…The levels of PRL and PL did not vary significantly during the tolerance tests. Lack of variation in PL levels has pre viously been reported during an oral glucose tolerance test in healthy pregnant women and women with GDM [28], GHBP was higher in the GDM group compared to the control group. The increased GHBP levels in the women with GDM were apparently a consequence of increased BMI in these women and not of the GDM state per se.…”

Placental Lactogen in the Goat in Relation to Stage of Gestation, Number of Fetuses, Metabolites, Progesterone and Time of Day

“…Using a 6 hourly sampling protocol in sheep, Chan et al (1978) found little variation in PL concentrations in late pregnancy. However, recent studies suggest that concentrations of human PL are not as stable as was formerly thought, rapid changes of up to twofold occurring in some patients (Pavlou, Chard & Letchworth, 1972;Lindberg & Nilsson, 1973;Vigneri, Squatrito, Pezzino, Cinquerui, Proto & Montoneri, 1975;Gillmer, Beard, Oakley, Brooke, Brudenell & Chard, 1977). The cause of variations in concentrations of PL in the circulation is unknown.…”

Serum Levels of Human Placental Lactogen During and After Prenatal Dexamethasone Therapy

“…Thus fasting and hypoglycemia bring about a rise in HPL levels, while hyperglycemia causes a fall (5, 8, 19, 24). In normal or diabetic women in the third trimester of pregnancy other investigators have been unable to demonstrate changes in HPL levels corresponding to changes in blood glucose, when the latter are brought about by oral glucose tolerance tests (6,9).…”