Mothers given 600 milligrams of docosahexaenoic acid (DHA) throughout pregnancy had babies that were less likely to be very low birth weight and born before 34 weeks gestation than infants of mothers who were given a placebo, according to the findings of a new clinical trial published in the American Journal of Clinical Nutrition.
The US-based researchers behind the study said their findings greatly strengthen the case for using dietary supplementation of DHA during pregnancy.
"A reduction in early preterm and very low birth weight delivery could have clear clinical and public health significance," said Professor Susan Carlson from the University of Kansas – who directed the study.
Carlson commented that she believes supplementing with DHA could safely increase birth weight and gestational age in many countries to numbers that are close to countries such as Norway and Australia.
The study results are from the first five years of a 10-year, double-blind randomised controlled trial.
In the trial 350 women were randomised to consume either 600mg DHA or placebo supplements from before the 20th week of gestation to birth.
The DHA supplementation resulted in higher maternal and cord blood-phospholipid-levels of DHA, a longer gestation duration, and greater birth weight, length and head circumference, said the researchers.
“In addition, the DHA group had fewer infants born at <34 wk of gestation and shorter hospital stays for infants born preterm than did the placebo group.”
Carlson and her team added that a follow-up of this sample of infants is currently ongoing, and aims to determine whether prenatal DHA nutritional supplementation will benefit children's intelligence and school readiness.
Children of women enrolled in the study received multiple developmental assessments at regular intervals throughout infancy and at 18 months of age. In the next phase of the study, the children will receive twice-yearly assessments until they are 6 years old.
The team plan to assess developmental milestones that occur in later childhood and are linked to lifelong health and welfare.
Previous research has established the effects of postnatal feeding of DHA on infant cognitive and intellectual development, but DHA is accumulated most rapidly in the foetal brain during pregnancy, said Colombo.
"That's why we are so interested in the effects of DHA taken prenatally, because we will really be able to see how this nutrient affects development over the long term."
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.112.050021
"DHA supplementation and pregnancy outcomes"
Authors: Susan E Carlson, John Colombo, Byron J Gajewski,Kathleen M Gustafson, David Mundy,