Impact of n-3 polyunsaturated fatty acid intake in pregnancy on maternal health and birth outcomes: systematic review and meta-analysis from randomized controlled trails

Background Maternal omega-3 consumption during pregnancy has been positively linked with a positive impact on maternal health and fetal growth. However, the results of individual studies are inconsistent and conflicting. Objective Examine the effect of supplementation with DHA, and/or EPA, and/or ALA throughout pregnancy on offspring's growth and pregnancy outcomes. Design A systematic review and meta-analysis. Population Pregnant women. Methods According to (PRISMA) statement and the Cochrane Handbook guidelines. Human trials (RCT or quasi-RCT) which involved oral omega-3 supplementation at least twice a week during pregnancy were included and comparing it with control groups with no supplementation or placebo administration. Data were extracted and directed using RevMan software. Fifty-nine randomized controlled trials were eligible for inclusion in the meta-analysis. Performed in MEDLINE, PubMed, Scopus, Google Scholar, and the Cochrane Library comparing omega 3 with control groups, from 1990 to 2020. The main outcome measures The primary outcome measures were pregnancy-induced hypertension, preeclampsia, gestational duration, preterm birth, early preterm birth, birth weight, low birth weight, neonatal length, and head circumference. The secondary outcomes were neonatal intensive care unit, infant death, prenatal death, and cesarean section. Results In 24 comparisons (21,919 women) n-3 fatty acids played a protective role against the risk of preeclampsia (RR= 0.84, 95% CI 0:74-0.96 p= 0.008; I-2 =24%). In 46 comparisons (16,254 women) n-3 fatty acids were associated with a significantly greater duration of pregnancy (MD=1.35, 95% CI 0.65-2.05, p = 0.0002; I-2 =59%). 27 comparisons (15,510 women) was accompanied by a significant decrease in pre-term birth less than 37 weeks (RR= 0.86, 95% CI 0.77-0.95, p= 0.005; I-2=0%). 12 comparisons (11,774 women) was accompanied by a significant decrease in early pre-term birth less than 34 weeks (RR= 0.77, 95% CI 0.63-0.95, p= 0.01;I-2 =40%). 38 comparisons (16,505 infants) had a significant increase in birth weight (MD=49.19, 95% CI 28.47-69.91, p <0.00001;I-2 =100%). Finally, 14 comparisons (8,449 infants) had a borderline significance in increase in low birth weight (RR =0.88, 95% CI 0.78-1.00, p =0.05; I-2 =28%). Conclusions Supplementation with omega-3 in prgnancy can prevent preeclampsia, increase gestational duration, increase birth weight and decrease the risk of low birth weight and preterm birth. [GRAPHICS] .