Association Between Use of Oral Contraceptives and Folate Status: A Systematic Review and Meta-Analysis

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#contraceptives-oral #erythrocytes #female #folic-acid #humans

Association Between Use of Oral Contraceptives and Folate Status: A Systematic Review and Meta-Analysis

Shere et al., 2015 | J Obstet Gynaecol Can | Meta Analysis

Citation

Shere Mahvash, Bapat Priya, ... Koren Gideon. Association Between Use of Oral Contraceptives and Folate Status: A Systematic Review and Meta-Analysis. J Obstet Gynaecol Can. 2015-May;37(5):430-438. doi:10.1016/S1701-2163(15)30258-9

Abstract

OBJECTIVE: To conduct a systematic review and meta-analysis of the effect of oral contraceptive use on plasma and red blood cell (RBC) folate concentrations. METHODS: We searched Medline, EMBASE, Web of Science, and the Cochrane library for human studies published from inception to June 2013 evaluating oral contraceptive use and folate status. Case-control studies, cohort studies, and clinical trials were included. A random-effects model of outcomes was used for the meta-analysis. RESULTS: A total of 2831 women in 17 studies were included in the analysis. In those whose plasma folate concentrations were available, there was a significant folate-lowering effect of oral contraceptives observed (mean reduction 1.27 µg/L; 95% CI 1.85 to 0.69, P < 0.001). Similarly, after analyzing data from 1389 women in 12 studies whose RBC folate concentrations were available, significantly lower folate status was observed among oral contraceptive users (mean reduction 59.32 µg/L; 95% CI 58.03 to 23.04, P < 0.001). CONCLUSION: Because of the reduction in blood folate concentrations associated with the use of oral contraceptives, it is critical for women of childbearing age to continue folate supplementation during oral contraceptive use.

Key Findings

A total of 2831 women in 17 studies were included in the analysis. In those whose plasma folate concentrations were available, there was a significant folate-lowering effect of oral contraceptives observed (mean reduction 1.27 µg/L; 95% CI 1.85 to 0.69, P < 0.001). Similarly, after analyzing data from 1389 women in 12 studies whose RBC folate concentrations were available, significantly lower folate status was observed among oral contraceptive users (mean reduction 59.32 µg/L; 95% CI 58.03 to 23

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 17
Age Range See abstract
Condition See abstract

MeSH Terms

  • Contraceptives, Oral
  • Erythrocytes
  • Female
  • Folic Acid
  • Humans
  • Plasma
  • Socioeconomic Factors

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: folate

Provenance

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