Longitudinal analysis of maternal plasma leptin concentrations during normal pregnancy and pre-eclampsia

Leptin concentrations have been found to be elevated in cross-sectional stu dies of established pre-eclampsia. Circulating concentrations of leptin wer e measured in cross-sectional study to confirm these findings (19 women wit h pre-eclampsia and 13 normal pregnant controls) and in a longitudinal stud y to establish the timing of the increase in leptin concentrations (samples obtained at 16, 20, 24, 28, 32, 36 and 38 weeks gestation from eight women who went on to develop pre-eclampsia and seven normal pregnant controls), In the cross-sectional study, plasma leptin concentrations were significant ly greater in women with pre-eclampsia than in normal controls (P = 0.001). In the longitudinal study, it was found that circulating leptin concentrat ions rose gradually to 32 weeks and thereafter declined slightly in normals . The concentrations in women destined to develop pre-eclampsia were consis tently higher from 20 weeks gestation (P = 0.04-0.003) and, in contrast to the normal controls, rose markedly from 32 weeks as pre-eclampsia developed . This study confirms that plasma leptin concentrations are increased in es tablished pre-eclampsia and reports for the first time that leptin concentr ations are elevated before pre-eclampsia is clinically evident.