Introduction & Objective: High levels of homocystein are a risk factor for insulin resistance, diabetes mellitus and cardio-vascular complications. This study was done to assess serum homocystein and folic acid levels and their relationship in women with gestational diabetes and compare them with normal pregnant women.

Materials & Methods: This analytic epidemiologic case-control study was performed in Qazvin Kosar hospital in 2013-2015. 120 singleton pregnant women with 24-28 weeks of gestation according to 2-hour 75g oral glucose tolerance test were assigned to two groups gestational diabetes (n=60), and normal pregnancy (n=60). Serum homocystein and folic acid levels were measured in two groups. Data were analyzed with statistical t-test and correlation method.

Results: In gestational diabetes serum homocystein level was significantly higher (P<0.001) and folic acid was significantly lower (P<0.001) than normal pregnancy group .No relation-ship was observed between serum homocystein and serum folate. In both groups, serum folic acid was significantly related to fasting blood sugar. This relationship was inverse in gesta-tional diabetes group (P<0.001, r = - 0.512) and direct in normal pregnancy group (P=0.001 r =0.417).

Conclusion: It seems folic acid has a role in regulation of serum homocystein level and blood sugar.