['To investigate the hypothesis that bone turnover is reduced in pre-eclampsia compared with normal pregnancy.', 'A prospective cross-sectional study.', 'Obstetric unit at the Chelsea and Westminster Hospital, London.', 'Third trimester maternal plasma levels of the cross-linked carboxyl-terminal telo-peptide of type I collagen (ICTP), (a marker of bone resorption) and the carboxyl terminal pro-peptide of type I pro-collagen (PICP), (a marker of bone formation) were compared in 25 women with pre-eclampsia and in 24 normal pregnant controls. The subjects were matched for maternal age, booking body mass index and gestational age. PICP and ICTP levels were measured by radio-immunoassay.', 'ICTP and PICP levels were significantly increased in women with pre-eclampsia compared with the normal pregnant controls (P = 0.0001 and P = 0.004, for ICTP and PICP respectively, Wilcoxon signed ranked test). There was no significant correlation between either of the markers and booking body mass index, blood pressure, serum uric acid levels or platelet count.'] Are biochemical markers of maternal bone turnover elevated in pre-eclampsia?