Increased Intake of DHA During Pregnancy Results in Increased Gestational Length

November 23, 2015


The Effect of Omega-3 Docosahexaenoic Acid Supplementation on Gestational Length: Randomized Trial of Supplementation Compared to Nutrition Education for Increasing n-3 Intake from Foods
Harris, M. A. et al., Biomed Research International , in press , 2015
Dept. of Food Sci. and Nutrition, Colorado State Univ., Fort Collins, CO and Dept. of Obstetrics and Gynecology, Denver Health Medical Ctr., Denver, CO, USA


The present study was designed to evaluate the impact of DHA omega-3 supplementation and a nutritional education strategy during pregnancy on gestational length (infant development time until birth). For this purpose , pregnant women (aged 18-40 years) recruited between 16-20 weeks of gestation were assigned to receive either no DHA supplement (‘placebo’ control group) or 300 mg or 600 mg DHA daily (from an algal source). A separate group of women were recruited to receive a nutrition education program which emphasized the importance of increased DHA intakes from food sources (fish, DHA-enriched eggs). A total of 563 women completed the study. Overall measures of DHA levels in blood samples from the ‘placebo’ or DHA subjects were not different from each other at the beginning; however, with DHA supplementation, the DHA levels were increased at delivery when compared to the ‘placebo’ control group. As compared to the controls (not receiving DHA supplementation), a significant increase in gestational length by 4 days was found with 600 mg DHA supplementation daily and by 4.5 days in the DHA education group. The early preterm birth rate of 1.7 % in those supplemented with DHA (300 or 600 mg daily) was significantly lower than the rate of 5.7 % in the ‘placebo’ control group. The authors concluded that supplementation with DHA or nutrition education programs which promote DHA intakes from food sources can be effective in increasing gestational length.

Dr. Holub's Comments:

The present study indicating a significantly lessened prevalence of early preterm birth with DHA supplementation during pregnancy is in general support of two fairly recent clinical trials from Australia and the USA. The former study by Makrides et al. (J. Am. Med. Assoc., 304: 1675-1683 (2010)) reported that the prevalence of preterm babies was only 1.1 % from pregnant women supplementing with 800 mg DHA (plus 100 mg EPA) daily as compared to 2.3 % from mothers not taking supplemental DHA. The study from the USA by Carlson et al. (Am. J. Clinical Nutrition , 97: 808-815 (2013)) reported a much lower prevalence of gestation periods below 34 weeks in pregnant women supplementing with 600 mg DHA/day as compared to those in the control group not receiving DHA supplementation along with a much lower prevalence of low birth weight infants (birth weights below 2500 gm) in the former group (only 3.9 % ) as compared to 9.0 % in the control group. While folic acid (folate) supplementation is widely recommended before conception and during the first few weeks of pregnancy to help prevent neural tube defects, it is becoming ever more apparent that the optimal health of many newborn infants could be enhanced by increasing DHA intakes (via food sources and/or supplementation) during pregnancy in vulnerable sectors of the global population.

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