Is enoxaparin necessary to prevent adverse pregnancy outcomes in methylenetetrahydrofolate reductase polymorphism positive recurrent pregnancy loss cases?

The association between methylenetetrahydrofolate reductase polymorphism and recurrent pregnancy loss is still under debate. Moreover, the use of enoxaparin to prevent adverse pregnancy outcomes is controversial in these patients. We aimed to analyse the effect of enoxaparin on pregnancy outcomes in recurrent pregnancy loss with only methylenetetrahydrofolate reductase gene polymorphism. A total of 339 pregnant women with recurrent pregnancy loss and methylenetetrahydrofolate reductase gene polymorphism between June 2017 and March 2019 were included. Patients were divided into two groups: enoxaparin plus folic acid (n=165) and folic acid group (n=174). Then, these groups were divided into subgroups: MTHFR A1298C homozygous (n=52), MTHFR A1298C heterozygous (n=141), MTHFR C677T homozygous (n=56) and MTHFR C677T heterozygous (n=90). Pregnancy outcomes were recorded and compared between two main group, and also between subgroups. There was no significant difference between enoxaparin plus folic acid group and only folic acid group according to delivery week (p=0.287), birthweight (p=0.677), miscarriage (p=0.372), stillbirth (p=0.585), live birth (p=0.246), preterm birth (p=0.700), anomaly (p=0.883), preeclampsia (p=0.656), intrauterine growth restriction (p=0.764), neonatal intensive care unit admission (p=0.820), APGAR 1st minutes<7 (p=0.729), APGAR 5th minutes<7 (p=1.000) and cesarean delivery (p=0.540). Furthermore there was no statistically significant difference with regard to delivery week, birthweight, miscarriage, stillbirth, live birth, preterm birth, anomaly, preeclampsia, intrauterine growth restriction, neonatal intensive care unit admission, APGAR 1st minute <7, APGAR 5th minute <7 and cesarean delivery between each subgroups. Contrary to the increasing trend of using empirical therapy with low molecular weight heparin in Turkey, we firstly demonstrated that there is no necessity to use enoxaparin to improve pregnancy outcomes both in homozygous and heterozygous methylenetetrahydrofolate reductase polymorphism related pregnancy loss cases. We suggest that only folic acid is enough for these cases.