Regulation of maternal IGF-I by placental GH in normal and abnormal human pregnancies.
Throughout gestation, maternal insulin-like growth factor I (IGF-I) increases progressively despite suppressed pituitary growth hormone (GH) secretion. We have previously shown that in normal pregnancy, a specific placental GH variant, rather than human placental lactogen (hPL), substitutes for pituitary GH in the regulation of maternal IGF-I. We studied the maternal IGF-I secretion in a cohort of 286 normal and abnormal pregnancies (617 blood samples). Regardless of pathology and gestational age, IGF-I values correlated with corresponding placental GH but not with hPL values. Similar correlations were evidenced for each 2-wk gestational period between 32 and 39 wk. In pathological pregnancies, when only those hormonal results that are obtained before any treatment are considered and diabetes is excluded, IGF-I levels were closely related to corresponding placental GH, but not to hPL. In women with a fetoplacental unit disorder, low placental GH levels resulted in low IGF-I and in a secondary pituitary GH increase, whereas in patients without detectable impairment of the fetoplacental unit normal placental GH corresponded to normal IGF-I. These results suggest that in pathological as well as in normal pregnancy, placental GH, and not hPL, substitutes for pituitary GH to regulate the maternal IGF-I secretion.
Caufriez
A
A
Department of Obstetrics and Gynecology, Université Libre de Bruxelles, Belgium.
Frankenne
F
F
Hennen
G
G
Copinschi
G
G
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood; D016640:Diabetes, Gestational / Q000097:blood; D005260:Female; D005315:Fetal Diseases / Q000097:blood; D013006:Growth Hormone / Q000502:physiology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D010920:Placenta / Q000378:metabolism*; D010922:Placenta Diseases / Q000097:blood; D010928:Placental Lactogen / Q000097:blood; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood* / Q000503:physiopathology*; D012016:Reference Values; D012044:Regression Analysis
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D010928:Placental Lactogen