Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes other than neural tube defects

There is insufficient evidence of benefit of folic acid supplementation during pregnancy on pregnancy outcomes other than neural tube defects.

The quality of evidence is downgraded by study limitations (lack of/unclear allocation concealment and blinding) and indirectness (differences between the outcomes of interest and those reported).

Summary

A Cochrane review included 31 studies with a total of 17771 subjects. Inclusion criteria were all randomised, cluster-randomised and cross-over controlled trials evaluating supplementation of folic acid alone or with other micronutrients versus no folic acid (placebo or same micronutrients but no folic acid) in pregnancy.

Folic acid supplementation had no impact on pregnancy outcomes such as preterm birth (RR 1.01, 95% CI 0.73 to 1.38; three studies, 2959 participants), and stillbirths/neonatal deaths (RR 1.33, 95% CI 0.96 to 1.85; three studies, 3110 participants). Improvements were seen in the mean birthweight (MD 135.75, 95% CI 47.85 to 223.68). No impact on improving pre-delivery anaemia was found (average RR 0.62, 95% CI 0.35 to 1.10; eight studies, 4149 participants; random-effects), mean pre-delivery haemoglobin level (MD -0.03, 95% CI -0.25 to 0.19; 12 studies, 1806 participants), mean pre-delivery serum folate levels (SMD 2.03, 95% CI 0.80 to 3.27; eight studies, 1250 participants; random-effects), and mean pre-delivery red cell folate levels (SMD 1.59, 95% CI -0.07 to 3.26; four studies, 427 participants; random-effects). A significant reduction was seen in the incidence of megaloblastic anaemia (RR 0.21, 95% CI 0.11 to 0.38, four studies, 3839 participants).

Clinical comments

Date of latest search: 2013-01-02

Ədəbiyyat

1. Lassi ZS, Salam RA, Haider BA et al. Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes. Cochrane Database Syst Rev 2013;3():CD006896.