Omega-3 fatty acids may benefit course of pregnancy

March 11, 2013

According to a new US study a daily supplementation with docosahexaenoic acid in the last half of gestation may reduce the risk of preterm birth and very-low birth weight.

To investigate potential effects of increased omega-3 fatty acid intake during pregnancy on gestation duration and birth size, the randomized controlled trial involved 350 pregnant women who consumed a capsule with 600 mg docosahexaenoic acid (DHA) or placebo from week 19 to birth (1). The study results showed that in comparison with placebo, DHA supplementation resulted in higher concentrations of maternal and umbilical cord red blood cell (RBC) phospholipid DHA, longer gestation duration (an average of 2.9 days) and greater birth weight (172 g), length (0.7 cm), and head circumference (0.5 cm). In addition, the DHA group had fewer infants born before 34 weeks of gestation and shorter hospital stays for infants born preterm than did the placebo group. No safety concerns were identified.

The researchers concluded that supplementing US women with DHA could safely increase mean birth weight and gestational age to numbers that are closer to those found in other developed countries such as Norway and Australia. In the United States, women have a mean gestation of 270.9 days, and the mean birth weight of infants is about 3,390 g. Moreover, a decline in US birth weight since 1990 suggests that there is room for improvement in birth weight and gestation duration.

Adequate omega-3 fatty acid intakes are of interest during pregnancy, because there is evidence that they can improve pregnancy outcomes, such as gestation duration, and because they are also believed to in-crease infant growth and enhance short- and long-term development of the offspring. Whether or not this is beneficial to the overall health and development of most infants is open to investigation. The results of earlier randomized supplementation trials were mixed as they used various doses (with as little as 100 mg DHA/day) and DHA sources (from food and supplements).


  1. Carlson S. E. et al. DHA supplementation and pregnancy outcomes. Am J Clin Nutr. Published online February 2013.