DHA Supplementation and Birth Size in Women having First Baby

December 13, 2010


Effects of Docosahexaenoic Acid Supplementation during Pregnancy on Gestational Age and Size at Birth: Randomized , Double-blind, Placebo-controlled Trial in Mexico
Ramakrishnan, A. et al., Food and Nutrition Bulletin , 31: S108-S116 , 2010
Hubert Dept. of Global Health , Rollins School of Public Health , Emory University,Atlanta, Georgia, USA and Inst. Mexicano del Seguro Social , General Hospital, Cuernavaca , Morelos , Mexico


A total of 1094 pregnant women received either a placebo supplement (controls) or 400 mg DHA/day from 18-22 weeks of gestation through delivery. Their background median dietary intake of DHA was estimated to be 55 mg/day. Primigravidae women (those having their first baby) represented 38 % of the mothers. Significant differences (expressed as p< 0.05) in outcomes were found between the two groups of mothers (receiving or not receiving supplemental DHA) if they were having their first baby but not for the others. For the primigravidae women, moderate but significantly greater birthweights and head circumferences were found for the infants from the DHA-supplemented mothers as compared to controls. Also, only 7.1 % of the babies from the DHA mothers exhibited intrauterine growth retardation as compared to 14.0 % for the other babies. The authors suggest that prenatal DHA supplementation of pregnant women having their first baby may result in increased birth size if their dietary DHA intakes are low.

Dr. Holub's Comments:

This study highlights the concept that clinical trials with omega-3 supplementation during pregnancy should attempt to evaluate sub-groups within the test population ( primigravidae mothers , those with differing DHA intakes/status based on biomarkers suich as blood measures of DHA, other factors) . It is noted that the so-called ‘very low intakes’ of DHA in the present groups of Mexican women (median of 55 mg DHA/day) are not much different than reported DHA intakes amongst expectant mothers in North America.

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