Polymorphisms in VEGF, progesterone receptor and IL-1 receptor genes in women with recurrent spontaneous abortion

Hormonal, inflammatory and vascular alterations during pregnancy are thought to be involved in pregnancy loss. The role of progesterone, the actions of which involve cytokines and vascular endothelial growth factor (VEGF), has been thoroughly studied. Genetic factors are involved in modulation of these molecules, and several genes have been associated with recurrent spontaneous abortion (RSA), as well other obstetric conditions. Here we investigate the relationship between RSA and gene polymorphisms of the progesterone receptor (PROGINS), interleukin-1 receptor 1 (PstI) and vascular endothelial growth factor (VEGF) (-634, 936). This case-controlled study comprised a total of 89 women with idiopathic RSA and a control group of 191 women with at least two successful pregnancies and no miscarriages. Genomic DNA was extracted from whole blood, and polymorphism genotyping was conducted by digesting PCR products with specific restriction endonucleases. No correlations were found in any of the investigated polymorphisms, even among dominant, co-dominant and additive inheritance models and alleles. Our results support the hypothesis that these specific gene polymorphisms are not the major determinant of pregnancy success. Although we did not find any correlations, the investigation of these and other polymorphisms remains a challenge in the evaluation of RSA.