['The polymorphisms of peroxisome proliferator-activator receptor-gamma2 (PPAR-gamma2) have been suggested to affect glucose metabolism and weight gain. Both conditions show great variations during pregnancy that makes pregnancy a suitable condition to detect any metabolic abnormalities related to PPAR-gamma2 polymorphisms. The objective of this study is to investigate the prevalence and metabolic impacts of PPAR-gamma2 polymorphism in control pregnant women and in patients with gestational diabetes mellitus (GDM).', 'In this case-control study, anthropometric and metabolic variables of 100 non-diabetic pregnant women and of 62 women who were diagnosed as having GDM according to 100 g oral glucose tolerance test (OGTT) were compared on the basis of PPAR-gamma2 polymorphism by univariate analysis of covariance.', 'There were no statistically significant differences in baseline characteristics and the mean 50 g glucose challenge test values of pregnant women in both groups on the basis of PPAR-gamma2 genotype, although patients with Pro12Ala polymorphism were significantly taller in GDM group. The Pro12Ala polymorphism had no effect on 100 g OGTT results of patients with GDM. However, patients with GDM who had Pro12Ala polymorphism gained significantly more weight during their pregnancy.'] Is pPAR-gamma2 Pro12Ala polymorphism associated with weight gain in women with gestational diabetes mellitus?