Docosahexaenoic Acid and Pregnancy: A Systematic Review and Meta-Analysis of the Association with Improved Maternal and Fetal Health

This study aimed to investigate the effects of prenatal docosahexaenoic acid (DHA) supplementation on pregnancy outcomes through a systematic review and meta-analysis. We hypothesized that prenatal DHA intake through supplements will improve pregnancy outcomes. Detailed literature search was performed using online databases such as PubMed, EMBASE, and Google Scholar till November 2022, to identify the randomized controlled trials (RCT) with maternal intake of DHA supplementation during the latter half of pregnancy compared to the placebo/control. Based on the inclusion and exclusion criteria, nine RCTs involving 5710 subjects were included. This meta-analysis showed that DHA supplementation (450-800 mg/day) was associated with a significantly higher birth weight of infants (Inverse variance [IV]: 101.71 [57.36-146.06] at 95% CI, P = .00001, I² = 0%), and fewer low birth weights (LBWs) (Mantel–Haenszel [M–H]: 0.53 [0.33-0.86] at 95% CI, P = .01, I² = 72%), with lesser but statistically insignificant pre-term births (PTB) (M–H: -0.02 [-0.04 to 0.00] at 95% CI, P = .07, I² = 0%) compared to the placebo. However, the DHA supplementation has no effect on gestational length (IV: -2.26 [-9.64 to 5.12] at 95% CI, P = .55, I² = 100%) compared to the placebo. In conclusion, the outcomes of this meta-analysis showed that prenatal DHA supplementation (450-800 mg/day) may reduce the risk of preterm births and increase infant birth weight.