Relation between first trimester maternal serum leptin levels and body mass index in normotensive and pre-eclamptic pregnancies--role of leptin as a marker of pre-eclampsia: a prospective case-control study.

Objective: We measured first trimester plasma leptin concentrations in 37 women who subsequently developed pre-eclampsia and 53 normotensive controls to determine the interrelation between leptin and body mass index (BMI) in both groups. We further investigated the association between the risks for pre-eclampsia with maternal leptin levels.

Methods: Bloods samples were collected at 13 weeks. Non-parametric tests, Spearman's correlation, linear regression analysis and multiple logistic regression analysis were applied in our data.

Results: 1 kg/m(2) increase in pre-pregnancy BMI was related to a 2.747 (95% CI: 3.242-2.252) ng/ml rise in leptin concentration among cases and 2.502 (95% CI: 2.873-2.131) ng/ml rise in leptin concentrations among controls. Increased leptin concentration (>or=25.3 ng/ml ) in lean women is associated with a 18.8-fold increased risk of pre-eclampsia (adjusted OR: 18.8, CI: 1.8-194, p = 0.014 ). Leptin treated as a continuous variable is a significant predictor of pre-eclampsia (adjusted OR: 1.08, CI: 1.018-1.133, p = 0.009).

Conclusion: Increased leptin concentration can definitely contribute to the prediction of pre-eclampsia in lean women, but this is not the case in overweight women. Further research in terms of longitudinal case-control studies is required to clarify the predictive value of pre-eclampsia.