Corticotrophin‐releasing hormone and corticotrophin‐ releasing hormone binding protein in normal and pre‐eclamptic human pregnancies

Abstract

Objective: To measure the plasma levels of corticotrophin‐releasing hormone and corticotrophin‐releasing hormone binding protein in normal pregnancy and in pregnancies complicated by pre‐eclampsia.

Setting: John Radcliffe Hospital, Oxford and St Thomas's Hospital, London.

Subjects: One hundred and twenty pregnant women sampled prospectively throughout gestation, of whom 91 experienced a normal pregnancy and eight developed pre‐eclampsia; in a second study, 10 women with severe pre‐eclampsia, presenting at a range of gestational ages, were sampled once and compared with appropriately matched normal pregnant women.

Main outcome measure: Plasma levels of corticotrophin‐releasing hormone determined by immunoradiometric assay. Plasma levels of corticotrophin‐releasing hormone binding protein measured by direct radioimmunoassay.

Results: In the prospective study, plasma samples from women with pre‐eclampsia exhibited higher (390.2 versus 292.7 pmol/l at 36 weeks) levels of corticotrophin‐releasing hormone and significantly lower (5.24 versus 8.14 nmol/l at 36 weeks, P 0.002) levels of corticotrophin‐releasing hormone binding protein than normal controls. In the second, single time point study a significant elevation in CRH (P < 0.002) and reduction in CRH‐BP (P < 0.001) was found in pre‐eclamptic pregnancies compared with controls.

Conclusions: In human pregnancies complicated by pre‐eclampsia there is an elevated level of corticotrophin releasing hormone whilst there is less corticotrophin‐releasing hormone binding protein; therefore there is a net increase in free potentially bioactive hormone which may play a role in the pathology of the disease.