Postnatal growth following maternal gestational supplementation with docosahexanoic acid (DHA): randomized placebo‐controlled trial in Mexico

Little is known about the long term benefits of ingesting DHA supplements during pregnancy. We have reported (Ramakrishnan et al., ICN 2009) that offspring of primiparous Mexican women who participated in a randomized double‐blind placebo‐controlled trial of 400 mg/day DHA from week 20 of gestation through delivery were heavier and had larger head circumferences (HC) at birth than children whose mothers received placebo; no effect was observed in offspring of multiparous women. We have followed these children through 18 mo of age (n= 739; 76% of the birth cohort), measuring length, weight and HC at 1, 3, 6, 9, 12, 18 mo. At 18 mo, intent‐to‐treat differences between the DHA and control groups were: length −0.22 cm (95% CI −0.58, 0.14); weight −0.03 kg (−0.19, 0.13); HC 0.01 cm (−0.18, 0.21) (all p>0.05 by t‐test). To assess the overall growth pattern through age 18 mo we used GEE; intent to treat analysis showed no association (p>0.4 for each test). For all 3 measures, the treatment by parity interaction had p<0.1. Among first‐borns, estimates were: weight 0.08 kg (−0.07, 0.23): length 0.55 cm (0.14, 0.96, p<0.05): HC 0.10 cm (−0.16, 0.35); among later‐borns, estimates were: weight −0.08 kg (−0.19, 0.03); length −0.19 cm (−0.50, 0.11); HC −0.20 cm (−0.40, −0.01, p<0.05). We conclude that growth patterns through age 18 mo following prenatal DHA supplementation in a study population with low intakes of DHA differ by maternal parity.