Vascular endothelial growth factor gene+813CC polymorphism of foetus is associated with preterm labour but not with pre-eclampsia in Turkish pregnant women

Abstract

We investigated the effect of polymorphism at +813 locus of vascular endothelial growth factor (VEGF) gene on predisposition to preterm labour and pre-eclampsia (PE). We examined polymorphism of the VEGF +813 gene of foetuses from umbilical cord blood in 31 cases of preterm labour, 34 pre-eclamptic and 58 healthy term labour. VEGF +813 gene polymorphisms were studied using a polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. In preterm group, foetal CC genotype was found at 80.6%, and CT genotype was seen at 19.4%. No any TT genotype was detected in preterm group. CC genotype of VEGF 813 gene was significantly more frequent than CT genotype (P = 0.04). Foetuses with CC genotype VEGF+813 gene have an increased risk for preterm labour. C allele frequency was 90.3 and 76.7% in preterm and control groups, respectively. T allele frequency was 9.7 and 23.3% in preterm and control groups, respectively. C allele was significantly associated with preterm labour (P = 0.02). OR of C and T alleles for preterm labour was 2.8 (CI: 1.17.2). In PE group, foetal CC genotype of +813 locus was found in 67.6%, and CT genotype was seen in 29.4%. Only one TT genotype was detected in 2.9% of PE group. There was no association between PE and VEGF gene genotypes and alleles at +813 locus. These results suggest that foetal VEGF gene polymorphism of +813 CC seems to be highly associated with preterm labour, whereas in PE, foetal VEGF gene polymorphism at +813 locus is not related. Especially, C allele was significantly associated with preterm labour. Carriage of the +813C allele of the VEGF gene has been found 2.8 times increased susceptibility to the development of preterm labour in Turkish women and may be an independent risk factor for prematurity. There was no association between PE and VEGF gene genotypes and alleles at +813 locus. We suggest to search for foetal aetiologies or genetic susceptibility in preterm labour, whereas in PE, not foetal, but maternal susceptibility is to be investigated.