Background: Placental angiogenesis and vascular adaptation during pregnancy, along with diminished placental trophoblastic vascular endothelial growth factor immunoreactivity, play an important role in the early stages of human pregnancy, being possible causes of recurrent pregnancy loss (RPL).
Aims: Our focus was directed towards investigating a possible association between vascular endothelial growth factor receptor-2 (kinase insert domain receptor) VEGFR-2 (KDR) -604A>G (rs 2071559) gene polymorphism and RPL in the study area of Dolj County, Romania.
Patients, materials and methods: In this study, 169 women, diagnosed with RPL, were included. They were hospitalized in the Clinics of Obstetrics and Gynecology, "Filantropia" Municipal Hospital, Craiova, during the following period: October 2009-October 2016. The control group consisted of 145 women. All subjects were genotyped by means of allelic discrimination TaqMan polymerase chain reaction assay with specific probes.
Results: No statistically significant difference was observed between the RPL patients and the control group, when one genotype was compared to another [in a dominant model, -604 AG+GG vs. AA: odds ratio (OR) 1.71, 95% confidence interval (CI) 0.99-2.96, p=0.051]. While studying the overall risk of RPL by the genotype frequencies of KDR polymorphism between controls and RPL patients, which were stratified according to the number of consecutive pregnancy losses (PLs), the chi-square test showed a significant association between the presence of this polymorphism and the increased risk observed in patients with four or more consecutive PLs, to develop RPL (in a dominant model - G allele carriers, KDR -604 AG+GG vs. AA: OR 1.91, 95% CI 1.03-3.52, p=0.037). These results prove that G allele carriers have an increased risk of RPL about 1.91-fold higher than those with the AA genotype do. Although our results bear limited statistical significance, the study nonetheless represents a step forward in the evaluation of recurrent abortion, which has not yet been explored sufficiently.
Conclusions: VEGFR-2 (KDR) polymorphism does not influence RPL susceptibility in the study area of Dolj County, Romania. Therefore, further studies, which include a larger sample size, are required in order to clarify the role of KDR polymorphism in RPL.