DHA supplementation during pregnancy does not reduce BMI or body fat mass in children: follow-up of the DHA to Optimize Mother Infant Outcome randomized controlled trial

Abstract

The omega-3 (n-3) long-chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) has proven effective at reducing fat storage in animal studies. However, a systematic review of human trials showed a lack of quality data to support or refute this hypothesis.We sought to determine whether maternal DHA supplementation during the second half of pregnancy results in a lower body mass index (BMI) and percentage of body fat in children.We conducted a follow-up at 3 and 5 y of age of children who were born to mothers enrolled in the DOMInO (DHA to Optimize Mother Infant Outcome) double-blind, randomized controlled trial, in which women with a singleton pregnancy were provided with DHA-rich fish-oil capsules (800 mg DHA/d) or vegetable-oil capsules (control group) in the second half of pregnancy. Primary outcomes were the BMIzscore and percentage of body fat at 3 and 5 y of age. Potential interactions between prenatal DHA and the peroxisome proliferator-activated receptor-γ (PPARγ) genotype as a measure of the genetic predisposition to obesity were investigated.A total of 1614 children were eligible for the follow-up. Parent or caregiver consent was obtained for 1531 children (95%), and these children were included in the analysis. BMIzscores and percentages of body fat of children in the DHA group did not differ from those of children in the control group at either 3 y of age [BMIzscore adjusted mean difference: 0.03 (95% CI: -0.07, 0.13;P= 0.61); percentage of body fat adjusted mean difference: -0.26 (95% CI: -0.99, 0.46;P= 0.47)] or 5 y of age [BMIzscore adjusted mean difference: 0.02 (95% CI: -0.08, 0.12;P= 0.66); percentage of body fat adjusted mean difference: 0.11 (95% CI: -0.60, 0.82;P= 0.75)]. No treatment effects were modified by thePPARγgenotype of the child.Independent of a genetic predisposition to obesity, maternal intake of DHA-rich fish oil during the second half of pregnancy does not affect the growth or body composition of children at 3 or 5 y of age. This trial was registered atwww.anzctr.org.auas ACTRN1260500056906 and ACTRN12611001127998.