Association of MTHFR gene C677T polymorphism with pregnancy outcome

The two objectives of the present study were to analyze the correlation between pregnancy outcomes and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism, and to provide evidence for clinical improvement of adverse pregnancy outcomes.

1,995 cases of pregnant women were selected as objects of the study, and underwent MTHFR gene C677T polymorphism detection in the Second Affiliated Hospital of Guangxi Medical University from October 2020 to September 2021, in which 919 cases whose pregnancy outcomes could be tracked. According to the result of MTHFR gene C677T polymorphism detection, 1,995 cases of pregnant women were classified into a wild-type (CC) group, heterozygous (CT) group, or homozygous (TT) group, and the distributions of MTHFR gene C677T polymorphism in pregnant women were analyzed. In addition, according to complications, 919 cases of pregnant women whose pregnancy outcomes could be tracked were divided into the normal pregnancy group (676 cases), GDM group (146 cases), HDP group (47 cases), abnormal fetus group (13 cases), and spontaneous abortion group (37 cases), and the genotype distributions of MTHFR gene C677T in each group were analyzed. Besides, according to genotype, 919 cases of pregnant women whose pregnancy outcome could be tracked were divided into CC group (515 cases), CT group (289 cases), and TT group (115 cases), and the correlation between genotype and pregnancy outcomes, such as fetal distress, postpartum hemorrhage, premature birth, and full-term delivery, was then analyzed.

For the C677T locus of MTHFR gene in the 1,995 cases of pregnant women, there are 1,162 (58.25%) cases of CC genotype, 649 (32.53%) cases of CT genotype, 184 (9.22%) cases of TT genotype. The proportion of TT genotype in GDM, HDP, abnormal fetus, and spontaneous abortion groups were respectively 19.86% (29/148), 25.53% (12/47), 46.15% (6/13), 40.54% (15/37), which were significantly higher than that in normal pregnancy group (7.84%, 53/676), and there were statistically significant differences (p < 0.05). The full-term birth rate in TT group (75.65%, 87/115) was lower than those of CC group (91.26%, 470/515) and CT group (89.27%, 258/289), and there were statistically significant differences (p < 0.05).

The TT type gene mutation at the C677T site ofMTHFR gene is closely related to conditions that contribute to a decrease in the number of full-term births and increase the risk of adverse pregnancy outcomes, including GDM, HDP, spontaneous abortion, and fetal abnormalities.