Outcomes of Folic Acid Supplementation During Pregnancy

Takeaway

• Folic acid supplementation during pregnancy was not associated with either adverse pregnancy outcomes or markers of offspring size at birth or adiposity.

Why this matters

• Maternal multiple micronutrient supplementation in pregnancy has been linked to increased offspring size at birth and adiposity and risk of gestational diabetes mellitus (GDM) in the Cambridge Baby Growth Study (CBGS).

Study design

• This study included 974 pregnant women from the CBGS. 
• 776 women received folic acid supplementation and 198 did not.
• Of 776 women, 526 received multiple micronutrient supplementation.
• Funding: European Union Framework 5 and others.

Key results

• Folic acid supplementation in pregnancy was not associated with (standardised β; 95% CI):
  • birth weight (−0.3 kg; −5.9 to 5.2; P=.90);
  • height (−1.3 cm; −6.3 to 3.6; P=.60);
  • head circumference (0.6 cm; −4.3 to 5.5; P=.80);
  • body mass index (1.0 kg/m²; −4.4 to 6.3; P=.70);
  • adiposity (ponderal index; 2.0 kg/m³; −3.2 to 7.1; P=.50); and
  • skinfold thickness:
    • flank (−2.9mm; −8.8 to 3.5; P=.40);
    • quadriceps (−0.4mm; −5.8 to 5.0; P=.90);
    • subscapular (−2.0mm; −8.1 to 4.1; P=.50); and
    • triceps (0.8mm; −5.4 to 7.1; P=.80).
• Similarly, folic acid supplementation had no significant association with adverse pregnancy outcomes (risk ratio; 95% CI):
  • GDM (1.2; 0.6-2.2);
  • gestational hypertension (0.7; 0.3-1.5);
  • pre-eclampsia (1.0; 0.3-3.6);
  • anaemia (1.6; 0.5-5.4); and
  • pre-term birth (<37 weeks gestation; 1.6; 0.5-5.4).

Limitations

• Data on folic acid supplementation were self-reported.

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.