MTHFR and Obesity: For GHT, we did not find a relationship between underweight and the two dominant models of MTHFR. Women who were overweight or obese were likely to experience GHT, and the highest odds ratio of GHT was observed in the obesity group for the A1298C AC + CC genotype (OR = 6.49, 95% CI = 2.67–15.79) and the C677T CC genotype (OR = 4.72, 95% CI = 2.13–10.45).