Hereditary thrombophilia genetic variants in recurrent pregnancy loss

Thrombofilias and the risk of recurring pregnancy loss in a Mexican population

“…23 Therefore, the relationship between fetal death and recurrent pregnancy loss was examined with the polymorphisms of MTHFR-C677T, PAI-1 4G> 5G, FVL-G1691A and PT-G20210A. This showed an increase of 14.2% (10.2% homozygous and 4% heterozygous) of patients with recurrent pregnancy loss who presented MTHFR-C677T, compared to the Control group (Graph 1) (Graph 2), in addition, also patients with fetal death that presented homozygous MTHFR-C677T, showed an increase of 17.8%, when compared with the control group (Graph 2), similarly, it was reported in 70 patients with recurrent pregnancy loss observed a 21.4% prevalence of MTHFR-C677T in comparison with the control group (0%); 23 Another study 25 in 245 patients with recurrent pregnancy loss observed 37% (30% heterozygous and 7% homozygous) more cases with MTHFR C677T, compared to the control group; Recently 26 in a meta-analysis they found that out of 10 studies analyzed, 8 presented an increase in patients with recurrent pregnancy loss who presented MTHFR C677T, where the study with the lowest incidence presented an increase of 3.7% and the one with greater than 24.5% (0.3 to 17% heterozygous and 0 to 31.5% homozygous) in comparison with respective control groups (Graph 1) (Graph 2).…”

“…finding a relationship between placental abruption and intrauterine growth restriction in patients with factor V Leiden mutation, which is one of the blood clotting factors. This mutation can increase the chances of developing abnormal blood clots, most often in the legs or lungs; 24,27,30 intrauterine growth restriction, preeclampsia, and placental abruption are associated with the MTHFR mutation and in addition to these complications, gestational loss in the second trimester is associated with the PT-G20210A mutation 31,32 and intrauterine growth restriction and loss gestational are associated with a PAI-1 4G mutation>5G; Others have found no association of thrombophilias with the increase in vascular lesions in placentas from term births and with some type of complication, but they do relate it as an underlying risk factor for lesions triggered by other processes; 25 similar to the review 26 where the relationship is weak in showing results of placental alterations when patients have thrombophilias, suggesting that alterations at the placental level during pregnancy is a prerequisite for thrombophilias to exert their deleterious effects. We observed a decrease in the weeks of gestational age, weight and height of newborns due to delivery in patients with a history of recurrent pregnancy loss, associated with the presence of FVL-G1691A (heterozygous and homozygous) and MTHFR C677T (heterozygous and homozygous ), with a small decrease in newborn height in patients with a history of fetal death, associated with the presence of MTHFR C677T (homozygous) and PAI-1 4G> 5G (heterozygous); which coincides with studies that report a decrease in birth weight in newborns of mothers who presented an increase in the blood of MTHFR C677T and FVL-G1691A mutations.…”

Pregnancy outcomes in patients with MTHFR gene polymorphism: A case series

“…The presence of heterozygous MTHFR C677T gene polymorphism was associated with an improved embryo quality and increased likelihood of pregnancy than homozygous genotypes. Similarly, Ahangari et al [19] evaluated the possible association between the MTHFR C677T, A1298C, F2G20210A, and F5G1691A genetic variants in Iranian women with recurrent miscarriage and found that the MTHFR C677Tm and A129C gene polymorphisms increased the recurrent pregnancy loss risk by 5.5 fold and 3.3 fold, respectively. In another case-control study conducted in India, recurrent early pregnancy loss was evaluated among 106 patients with the history of three or more recurrent early pregnancy loss and 140 healthy fertile controls with successful pregnancy outcomes [20].…”

Coagulation challenges in pregnancy: from thrombophilia involvement and management to the utility of thrombin generation monitoring

“…A meta-analysis published in 2003 found that factor V Leiden, the prothrombin gene G20210A mutation, and protein C and protein S deficiency were associated with recurrent pregnancy loss [32]. Women with two or more recurrent pregnancy losses had more frequent MTHFR C677T and A1298C mutant alleles in an Iranian study [33]. In a more recent study, late pregnancy loss appears to be associated with protein S deficiency, while the heterozygous mutations of factor V Leiden and FII 20210A are more common in later pregnancy complications, such as preeclampsia, second trimester loss, fetal growth restriction and placental abruption and less common in recurrent first trimester loss [34,35].…”