Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes

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#anemia #birth-weight #female #folic-acid #hemoglobin-a

Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes

Lassi et al., 2013 | Cochrane Database Syst Rev | Meta Analysis

Citation

Lassi Zohra S, Salam Rehana A, ... Bhutta Zulfiqar A. Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes. Cochrane Database Syst Rev. 2013-Mar-28;2013(3):CD006896. doi:10.1002/14651858.CD006896.pub2

Abstract

BACKGROUND: During pregnancy, fetal growth causes an increase in the total number of rapidly dividing cells, which leads to increased requirements for folate. Inadequate folate intake leads to a decrease in serum folate concentration, resulting in a decrease in erythrocyte folate concentration, a rise in homocysteine concentration, and megaloblastic changes in the bone marrow and other tissues with rapidly dividing cells OBJECTIVES: To assess the effectiveness of oral folic acid supplementation alone or with other micronutrients versus no folic acid (placebo or same micronutrients but no folic acid) during pregnancy on haematological and biochemical parameters during pregnancy and on pregnancy outcomes. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2012) and we contacted major organisations working in micronutrient supplementation, including UNICEF Nutrition Section, World Health Organization (WHO) Maternal and Reproductive Health, WHO Nutrition Division, and National Center on Birth defects and Developmnetal Disabilities, US Centers for Disease Control and Prevention (CDC). SELECTION CRITERIA: 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. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. MAIN RESULTS: Thirty-one trials involving 17,771 women are included in this review. This review found that folic acid supplementation has no impact on pregnancy outcomes such as preterm birth (risk ratio (RR) 1.01, 95% confidence interval (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). However, improvements were seen in the mean birthweight (mean difference (MD) 135.75, 95% CI 47.85 to 223.68). On the other hand, the review found no impact on improving pre-delivery anaemia (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 (standardised mean difference (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). However, 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). AUTHORS' CONCLUSIONS: We found no conclusive evidence of benefit of folic acid supplementation during pregnancy on pregnancy outcomes.

Key Findings

Thirty-one trials involving 17,771 women are included in this review. This review found that folic acid supplementation has no impact on pregnancy outcomes such as preterm birth (risk ratio (RR) 1.01, 95% confidence interval (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). However, improvements were seen in the mean birthweight (mean difference (MD) 135.75, 95% CI 47.85 to 223.68). On the other

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 2959
Age Range See abstract
Condition See abstract

MeSH Terms

  • Anemia
  • Birth Weight
  • Female
  • Folic Acid
  • Hemoglobin A
  • Humans
  • Maternal Welfare
  • Micronutrients
  • Pregnancy
  • Pregnancy Complications, Hematologic
  • Pregnancy Outcome
  • Premature Birth
  • Randomized Controlled Trials as Topic
  • Stillbirth
  • Vitamin B Complex

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't, Systematic Review
  • Vertical: folate

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09