The most common complication of pregnancy is idiopathic recurrent pregnancy loss (RPL). To identify the contribution of gene polymorphisms to this condition, we evaluated the association between RPL and the angiotensinogen (AGT), angiotensin receptor 1 (AGTR1) and Angiotensinogen converting enzyme (ACE). In this case-control study, the frequency of AGT (rs4762 and rs699), AGTR1 (rs5186) and ACE insertion/deletion (rs4340) polymorphisms in 202 idiopathic RPL women was compared with 210 women with no history of abortion, using tetra-primer ARMS-PCR. Polymorphisms were analysed by logistic regression analysis according to inheritance models. The CT genotype of AGT rs4762, the CC genotype of AGT rs699 and the AC genotype of AGTR1 rs5186 in a co-dominant inheritance model were associated with idiopathic RPL (OR = 1.63, 95% CI = 1.07-2.49 of CT versus CC; OR = 5.97, 95% CI = 1.28-27.82 of CC versus TT; and OR = 1.99, 95% CI = 1.22-3.07 of AC versus AA). The allele frequency of AGT rs699 and AGTR1 rs5186 polymorphisms, but not AGT rs4762 and ACE rs4340 polymorphisms were significantly different between women with RPL patients and controls (p = 0.020, p = 0.003, p = 0.105 and p = 0.065, respectively). These results show that there is a significant relationship between AGT (rs699) and AGTR1 (rs5186) polymorphisms and idiopathic RPL in the Iranian population.
Keywords: ACE; AGT; AGTR1; Recurrent pregnancy loss; polymorphism; renin–angiotensin system.