Effect of n‐3 Long‐chain Polyunsaturated Fatty Acid Intake during Pregnancy on Maternal, Infant, and Child Health Outcomes: A Systematic Review

Abstract

Evidence from observational studies and randomised trials has suggested a potential association between intake of n-3 long-chain polyunsaturated fatty acids (LCPUFA) during pregnancy and certain pregnancy and birth outcomes. Marine foods (e.g. fatty sea fish, algae) and select freshwater fish contain pre-formed n-3 LCPUFA, which serve as precursors for bioactive molecules (e.g. prostaglandins) that influence a variety of biological processes. The main objective of this analysis was to summarise evidence of the effect of n-3 LCPUFA intake during pregnancy on select maternal and child health outcomes. Searches were performed in PubMed, EMBASE, and other electronic databases to identify trials where n-3 LCPUFA were provided to pregnant women for at least one trimester of pregnancy. Data were extracted into a standardised abstraction table and pooled analyses were conducted using RevMan software. Fifteen randomised controlled trials were eligible for inclusion in the meta-analysis, and 14 observational studies were included in the general review. n-3 LCPUFA supplementation during pregnancy resulted in a modest increase in birthweight (mean difference = 42.2 g; [95% CI 14.8, 69.7]) and no significant differences in birth length or head circumference. Women receiving n-3 LCPUFA had a 26% lower risk of early preterm delivery (<34 weeks) (RR = 0.74; [95% CI 0.58, 0.94]) and there was a suggestion of decreased risk of preterm delivery (RR = 0.91; [95% CI 0.82, 1.01]) and low birthweight (RR = 0.92; [95% CI 0.83, 1.02]). n-3 LCPUFA in pregnancy did not influence the occurrence of pre-eclampsia, high blood pressure, infant death, or stillbirth. Our review of observational studies revealed mixed findings, with several large studies reporting positive associations between fish intake and birthweight and several reporting no associations. In conclusion, n-3 LCPUFA supplementation during pregnancy resulted in a decreased risk of early preterm delivery and a modest increase in birthweight. More studies in low-and middle-income countries are needed to determine any effect of n-3 LCPUFA supplementation in resource-poor settings, where n-3 PUFA intake is likely low. fish oil, pregnancy and birth outcomes, maternal health, infant health. Evidence from observational studies has suggested a potential association between intake of marine foods during pregnancy and certain pregnancy and birth outcomes. Researchers observed in the 1980s that women living in the Faroe Islands, where seafood is commonly consumed, had longer gestational duration and heavier babies than women living in Denmark. Keywords 1,2Additionally, researchers found that Greenland Inuits had lower rates of pre-eclampsia than Danish women. These observations instigated future research founded on the hypothesis that intake of marine foods in pregnancy might influence maternal and neonatal health outcomes.Marine foods are rich sources of the n-3 longchain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA,,...

Maternal dietary omega-3 fatty acids and placental function

“…Despite this, clinical trials of n-3 PUFA supplementation demonstrate conflicting results regarding pregnancy outcome (Imhoff-Kunsch et al 2012, Larqué et al 2012. It has been suggested that this is because supplementation is often begun during mid to late gestation (w22 weeks; Larqué et al 2012).…”

“…Given that n-3 PUFAs exhibit both anti-oxidative and antiinflammatory properties, maternal dietary n-3 PUFA supplementation has been proposed as a potential therapeutic intervention for placenta-related disorders. Indeed, maternal dietary supplementation with n-3 PUFAs during pregnancy can exert beneficial effects including increased gestation length and increased fetal growth (Imhoff-Kunsch et al 2012, Larqué et al 2012, Jones et al 2013a, and a reduced risk of pregnancy complications (Oken et al 2007). In this study, we review the impact of dietary n-3 PUFAs on placental function, with particular focus on placental fatty acid transport, inflammation, inflammatory resolution, oxidative status, and angiogenesis.…”

Dietary arachidonic acid in perinatal nutrition: a commentary

“…Women who deliver preterm have been demonstrated to have higher levels of AA and other n-6 LCPUFA in their blood and trophoblast tissue compared to women who deliver at term (13). Furthermore, maternal dietary supplementation with marine n-3 LCPUFA has been shown in randomized controlled trials (RCT) to reduce the risk of early preterm delivery (<34 wk) (relative risk = 0.74; (95% confidence interval = 0.58, 0.94)) and result in a modest increase in birth weight (14). Due to the role of AA-derived eicosanoids in the initiation of delivery it is biologically plausible that a slight dampening of this effect by competition with n-3 LCPUFA could explain a protective effect of n-3 LCPUFA against the risk of early labor (15).…”

Women who take n-3 long-chain polyunsaturated fatty acid supplements during pregnancy and lactation meet the recommended intake

“…A source of these long-chain fatty acids is required during pregnancy for fetal and placental development (reviewed by Mennitti et al 2015;Jones et al 2014). Maternal intake/status of n-3 LCPUFA during pregnancy and lactation has been found to positively impact maternal, infant, and child health in many systematic reviews (Yang et al 2013;Imhoff-Kunsch et al 2012;Larqué et al 2012;Horvath et al 2007). The importance of a dietary source of n-3 LCPUFA is supported by stable isotope tracer studies that found only 1%-4% of dietary ALA is converted to DHA (Pawlosky et al 2001;Emken et al 1994).…”