AbstractBackgroundPeroxisome proliferator activated receptor gamma (PPARG) belongs to the nuclear receptor superfamily functioning as transcription factors to regulate cellular differentiation, development and metabolism. Moreover, it has been implicated in the regulation of lipid metabolism, as well as the maturation of monocytes/macrophages and the control of inflammatory reactions. The aim of this study was to evaluate the relationship between the Pro12Ala (rs1808212)PPARGgene polymorphism on immune molecular and cellular components in mothers and their offspring participating in the PREOBE study.MethodsDNA from maternal venous blood samples at 24, 34 and 40 gestational weeks, plus cord blood samples was extracted. Pro12AlaPPARGpolymorphism genotyping was performed, and immune system markers were analyzed by flow cytometry.ResultsStudy findings revealed no effect of rs1808212PPARGgenotypes on innate immune parameters in mothers and their offspring; however, CD4 + /CD8 + ratio were decreased at 24 and 34 weeks in pregnant women carrying theCG(Pro12Ala) rs1808212 polymorphism, (p = 0,012 and p = 0,030; respectively). Only CD19 levels in peripheral blood were significantly higher at delivery in pregnant women carrying theCC(Pro12Pro) genotype (p ≤ 0.001). Moreover,there were statistically significant differences in leukocytes and neutrophils maternal levels at 34 weeks of gestation, being lower in carriers of Pro12Ala genotype (p = 0.028 and p = 0.031, respectively).ConclusionsResults suggest that Pro12AlaPPARGpolymorphism may have an effect on some cell and immune parameters in pregnant women during pregnancy and at time of delivery. However, newborn innate immune system does not seems to be influenced byPPARGPro12Ala polymorphism in cord blood.