The effect of prenatal DHA supplementation on offspring fat mass and distribution at 24 months old

Background Excessive gestational weight gain (GWG) is related to increased offspring fat accrual and increased fat mass (FM) is related to obesity development. Prenatal DHA supplementation has been linked to lower levels of offspring FM; however, conflicting data exists. Objectives Determine if there is a protective effect of prenatal DHA supplementation on offspring fat accrual and adipose tissue deposition at 24 months in offspring born to women who gain excessive versus non-excessive weight during pregnancy. We also explored if the effect of DHA dose on FM differed by offspring sex. Methods Infants born to women who participated in the Assessment of DHA on Reducing Early Preterm Birth randomized controlled trial (ADORE) were recruited. In ADORE, women were randomized to either a high or low prenatal DHA supplement. Offspring body composition and adipose tissue distribution were measured using DXA. GWG was categorized as excessive or not excessive based on clinical guidelines. Results For total FM, there was a significant main effect for DHA dose (p=0.03), however, the dose by GWG status was not significant (p=0.44). Therefore, a higher prenatal DHA dose was related to greater offspring FM (622.9 g greater), and unrelated to GWG status. When investigating a DHA dose by sex effect, a significant main effect for DHA dose (p=0.01) was detected for central FM. However, no interaction was detected (p=0.98), meaning both boys and girls had greater central FM if their mother was assigned to the higher dose. Conclusions Greater prenatal DHA supplementation was related to greater offspring FM and adipose tissue distribution at 24 months old. It will be important to understand if these effects persist into childhood. Clinical Trial Registry This trial was registered at ClinicalTrials.gov (NCT03310983)