Comparison study on the effect of prenatal administration of high dose and low dose folic acid.

OBJECTIVE To evaluate the effect of high dose and low dose folic acid on the levels of hemocysteine (Hcy) concentration during the first trimester of pregnancy and at delivery, and to examine the association of Hcy serum levels and preeclampsia. METHODS In a single blinded randomized clinical trial, which was conducted in Tabriz, Iran, from 2005-2008, 246 nulliparous pregnant women in 2 similar groups, received folic acid daily from early pregnancy until delivery (5 mg/day in group one and 0.5 mg/ day in group 2). The incidence of hypertension and laboratory changes in the levels of serum Hcy, lactate dehydrogenase, and uric acid in addition to the levels of urine creatinine and protein were compared between the groups. RESULTS There was no presence of any type of hypertension in each group. The systolic blood pressures (BP) (mm Hg) at the first trimester were 114.01 +/- 8.78 for group one, 114.16 +/- 9.05 for group 2, and at delivery, 117.24 +/- 6.91 for group one, and 117.23 +/- 11.48 for group 2 (p=0.32). The diastolic BP at the first trimester were 74.90 +/- 7.45 for group one, 73.30 +/- 8.90 for group 2, and at delivery 76.46 +/- 5.58 for group one, and 76.69 +/- 8.62 for group 2 (p=0.42). Although the level of Hcy (micromol/L) decreased significantly at the delivery time in group one (11.81+/- 3.85 decreased to 6.44 +/- 1.88), and 2 (9.08+/- 3.24, decreased to 7.44 +/- 2.99), this decrement was more significant in the first group (p<0.001). CONCLUSION The results show that folic acid supplement throughout pregnancy, irrespective of the dosage, could eliminate hypertensive disorders, and decreases serum level of Hcy, although it is reduced more significant in the first group.