Human Reproduction, Vol. 15, No. 6, 1403-1406,
June 2000
© 2000 European Society of Human Reproduction and Embryology
Antenatal dexamethasone and the growth hormone–insulin-like growth factor axis
1 Section of Obstetrics and Gynaecology, Imperial College School of Medicine, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, 2 Department of Medicine, King's College School of Medicine and Dentistry and 3 Department of Chemical Pathology, Imperial College School of Medicine, Charing Cross Hospital, London W6 9RF, UK
Dexamethasone administration has marked effects on the growth hormone-insulin-like growth factor axis (GH–IGF) in animal and human studies. During pregnancy in the rat, it is associated with fetal growth restriction due to inhibition of IGF bioactivity. In the human only repeated dosages have been associated with fetal growth restriction. The aim of this study is to test the hypothesis that antenatal dexamethasone administration to pregnant women is associated with reduced activity of the GH–IGF axis. To achieve this blood samples were taken from 12 pregnant women pre- and at 24 h and 48 h after dexamethasone administration. In these samples GH, IGF-I, IGF bioactivity and IGF binding protein (IGFBP)-3 protease activity were measured. In view of the interaction between insulin and the GH–IGF axis, glucose and insulin concentrations were also measured. There were no significant differences between the concentrations of GH, IGF-I, IGF bioactivity and IGFBP-3 protease activity before and after dexamethasone. The concentrations of glucose and insulin were significantly higher at 24 h, but not 48 h post-dexamethasone. It is concluded that a single antenatal course of dexamethasone does not alter the GH–IGF-I axis in pregnant women at the time points studied.
Key words: antenatal/dexamethasone/IGF
4 To whom correspondence should be addressed. E-mail: mark.johnson{at}ic.ac.uk