Preterm

Previous studies have suggested that maternal supplementation with n−3 long-chain polyunsaturated fatty acids; may reduce the incidence of preterm delivery but may also prolong gestation beyond term; however, more data are needed regarding the role of n−3 long-chain; polyunsaturated fatty acids in pregnancy. Maternal supplementation with n-3 long-chain polyunsaturated fatty acids did not reduce rates of early preterm deliveries, nor did it affect rates of post-term delivery interventions; according to randomized trial results published in The New England Journal of Medicine.

“The World Health Organization recommends an intake of 300 mg of n-3 long-chain polyunsaturated fatty acids; per day in pregnant women; however, the median intake among Australian and American women of childbearing; age is less than one-third of this,” Maria Makrides, PhD,of the South Australian Health and Medical Research Institute, and colleagues wrote.

N-3 long-chain polyunsaturated fatty acids

They performed a multicenter, double-blind, randomized trial in which women; who were pregnant with single or multiple fetuses were assigned to receive either fish-oil capsules that contained 900 mg of n−3 long-chain polyunsaturated fatty acids (n−3 group); or vegetable-oil capsules that contained trace n−3 long-chain polyunsaturated fatty acids (control group) daily; beginning before 20 weeks of gestation and continuing to 34 weeks of gestation or delivery, whichever occurred first.

The primary outcome was early preterm delivery; defined as delivery before 34 completed weeks of gestation. Other pregnancy and neonatal outcomes also assessed. Researchers also noted that data specific to the role of n-3 long-chain polyunsaturated fatty acids in pregnancy are lacking. Makrides and colleagues randomly assigned pregnant women in Australia to received fish-oil capsules; containing either 900 mg of n-3 long-chain polyunsaturated fatty acids (n = 2,734) or vegetable-oil capsules that contained trace amounts of n-3 long-chain polyunsaturated fatty acids (n = 2,752). Their daily intakes began before 20 weeks’ gestation; and continued to 34 weeks’ gestation or delivery, whichever occurred first.

Early preterm delivery

Researchers found that there were 61 early preterm deliveries in the n-3 group; and 55 early preterm deliveries in the vegetable-oil group. The between-group difference not significant (adjusted RR = 1.13; 95% CI, 0.79-1.63), they said. Although there was a higher percentage of infants born to women at more than 41 weeks’ gestation in the n-3 group that were very large for gestational age at birth; (adjusted RR = 1.3; 95% CI, 1.02-1.65), no other significant differences between the groups in terms of adverse events; or other pregnancy or neonatal outcomes reported.

In addition, minor gastrointestinal disturbances were more commonly reported in the n-3 group than in the control group, but percentages of serious adverse events did not differ between groups, according to researchers. “Further study need to determine whether there may be benefit in women who have low n-3 levels,” Makrides and colleagues wrote. Supplementation with n−3 long-chain polyunsaturated fatty acids from early pregnancy (<20 weeks of gestation) until 34 weeks of gestation did not result in a lower incidence of early preterm delivery or a higher incidence of interventions in post-term deliveries than control.