Background and Objective: Despite many of research, the cause of hypertension during pregnancy period has not been revealed. Disorders related to hypertension still remain among the most important unresolved maternity problems. The main goal of this work was to study the relationship between serum leptin levels and preeclampsia in Vali-e-asr Hospital of Zanjan from  March 2005 till March 2006.
Materials and Methods: This cross-sectional study was comprised of 2 groups of pregnant women in their last trimester. Each group consisted of 30 cases. The case group had blood pressure (BP) >140/90, and either proteinuria >300 μg/24h or +1 and more with dipstick. The control group had normal BP. The samples were analyzed with leptin kit using ELISA technique. Independent t-test was used to analyze the results.
Results: Despite the slightly higher serum leptin levels in the control group, the difference was not significant (57.9233.6 ng/dl vs. 45.834.6 ng/dl, respectively; p= 0.18).  Based on BMI>29, there was no significant differences in the serum leptin levels between the case and control groups (51.1239.72 ng/dl and 56.7534.84 ng/dl, respectively; p= 0.64).  However, based on BMI29, the serum leptin levels were significantly higher in the control group (36.7522.1 ng/dl vs. 60.2632.51 ng/dl, respectively, p=0.07).
Conclusion: The results of this study show that there is no significant relationship between preeclampsia and increased serum leptin levels. Further studies with prospective designs and a larger sample size are required to clarify any potential association between the serum leptin level and preeclampsia.