The benefits of taking DHA supplements during pregnancy

Supplement of 600 mg DHA/d in the last half of gestation will result in overall greater gestation duration and infant size. It is suggested that pregnant women should take DHA supplementation to reduce the number of infants born before 34 week of gestation along with the risks to the infant as well as costs to society of early preterm birth.

Omega-3 (n-3) long-chain polyunsaturated fatty acid (LCPUFA), especially docosahexaenoic (DHA), is needed during pregnancy because it can improve outcomes such as gestation duration. It is also believed to increase infant growth and enhance short- and long-term development of the offspring. Many studies have supplied DHA in some form to pregnant women and evaluated both pregnancy outcome and/or infant development with mixed results for both types of outcomes. Many variables exist among pregnancy supplementation studies that could explain the variability in outcomes such as dose, source of supplemental DHA and usual intake. This phase III, double-blind and randomized controlled trial was conducted to test the hypothesis that 600 mg/day of the n-3 LCPUFA DHA could increase maternal and newborn DHA status, gestation duration, birth weight, birth length and to evaluate the safety of DHA supplementation.

A phase III, double-blind, randomized controlled trial was designed, in which 350 women consumed capsules (172 were assigned to the placebo and 178 to DHA) from < 20 week of gestation to birth. Blood was analysed for red blood cell (RBC) phospholipid DHA. The statistical analysis was intent-to-treat. Results showed that in comparison with placebo, DHA supplementation led to higher maternal and cord RBC-phospholipid-DHA (P < 0.001) and longer gestation duration (P = 0.041). Gestational age was 2.87 d greater (P = 0.041). Birth weight (P = 0.004) and birth length (P = 0.012) were higher by 172 g and 0.7 cm, respectively. Head circumference (P = 0.012) was higher in newborns of women assigned to DHA than to placebo. The incidence of preterm birth did not differ between the groups but significantly more infants in the placebo group had an early preterm birth (P = 0.025). Infants born preterm in the DHA group spent fewer days hospitalized after birth (P = 0.026). Maternal RBC-phospholipid-DHA was correlated with birth weight and birth head circumference, whereas cord blood RBC-phospholipid-DHA did not correlate with any outcome. Moreover, the study did not identify any serious safety concerns associated with DHA supplementation for mother or newborn. Common reasons for hospitalization before birth were infection (4 placebo, 6 DHA) and premature rupture of membranes/threatened preterm birth (5 placebo, 1 DHA).

Supplement of 600 mg DHA/d in the last half of gestation results in an overall greater gestation duration and infant size. It is suggested that pregnant women should take DHA supplementation to reduce the number of infants born before 34 week of gestation along with the risks to the infant as well as costs to society of early preterm birth.

References

  1. Carlson, S.E., et al., DHA supplementation and pregnancy outcomes. Am J Clin Nutr, 2013. 97(4): p. 808-15.