Effect of Maternal Docosahexaenoic Acid Supplementation on Very Preterm Infant Growth: Secondary Outcome of a Randomized Clinical Trial

Introduction: The aim of the study was to determine the effect of a maternal docosahexaenoic acid (DHA) supplementation during lactation, compared with a placebo, on the neonatal growth profile of breastfed very preterm infants. Methods: Preterm infants' growth profile, growth velocity from birth to 36 weeks' postmenstrual age (PMA), and growth at 36 weeks' PMA were pre-specified secondary outcomes of a randomized placebo-controlled trial conducted in 16 Canadian neonatal intensive care units (2015-2018). Lactating mothers who delivered before 29 weeks' gestation were given 1.2 g of DHA daily or a placebo within 72 h of delivery and up to 36 weeks' PMA. Analyses were performed using a linear regression model with generalized estimating equations. Results: 461 mothers and their 528 infants (DHA, N = 273; placebo, N = 255) were included with mean gestational age of 26.5 weeks (standard deviation [SD] = 1.6); 275 (52.1%) were males; mean birth weight was 895 g (SD = 240). DHA interaction with sex was significant on weight profile (interaction p < 0.001), weight velocity (interaction p = 0.05), and weight at 36 weeks' PMA (interaction p = 0.02). Females in the DHA group gained more weight compared to the placebo group (mean difference [MD], 52.6 g [95% confidence interval [CI]: 24.5-80.8], p < 0.001). Weight velocity was significantly higher in females of the DHA group (MD, 3.4 g/kg/day [95% CI: 0.6-6.2], p = 0.02). At 36 weeks' PMA, the weight of males in the DHA group was significantly smaller (MD, -88.9 g [95% CI: -166.2 to -11.6], p = 0.02). Conclusion: DHA positively affected female infants' neonatal weight profile and velocity and negatively affected male infants' weight at 36 weeks' PMA.

Automated summary

This study found that maternal supplementation with docosahexaenoic acid (DHA) during lactation had an impact on the growth of preterm infants. DHA positively affected the weight gain and growth velocity of female infants, but had a negative effect on the weight of male infants at 36 weeks' postmenstrual age.