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Omega−3s improved maternal health and birth outcomes

This meta-analysis found that supplementation with omega−3s during pregnancy increased gestation by 1.4 days and birth weight by 49 grams. It also reduced the risks of preeclampsia (−16%), preterm delivery (−14%), and early preterm delivery (−23%).


Some evidence suggests that supplementation with omega−3 fatty acids during pregnancy may have beneficial effects on both maternal health and birth outcomes. What does the totality of the available clinical evidence say?

The study

This meta-analysis of 59 randomized and quasi-randomized controlled trials examined the effects of supplementation during pregnancy with omega−3s (i.e., docosahexaenoic acid and/or eicosapentaenoic acid and/or alpha-linolenic acid; aka DHA, EPA, and ALA), compared to placebo or no intervention, on a number of maternal health and birth outcomes.

The primary outcomes were the following:

  • Incidence of pregnancy-induced hypertension (11 trials)

  • Incidence of preeclampsia (24 trials)

  • Gestational duration (46 trials)

  • Incidence of preterm delivery (<37 weeks; 27 trials)

  • Incidence of early preterm delivery (<34 weeks; 12 trials)

  • Newborn birth weight (37 trials)

  • Low newborn birth weight (14 trials)

  • Newborn length (31 trials)

  • Newborn head circumference (26 comparisons)

The secondary outcomes were the following:

  • Risk of admission to the neonatal intensive care unit (13 trials)

  • Incidence of cesarean delivery (29 trials)

  • Prenatal death (12 trials)

  • Infant death (10 trials)

The results

Supplementation with omega−3s reduced the risk of preeclampsia by 16%, increased gestational duration by 1.4 days, increased newborn birth weight by 49 grams, and reduced the risk of preterm and early preterm delivery by 14% and 23%, respectively.

The risk of bias was low in 29 trials, moderate in 19 trials, and high in 11 trials.

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