In November 2018 researchers from Australia published their review of the medical scientific literature to assess the effect of omega-3 long chain polyunsaturated fatty acids, either as a supplement or dietary addition, taken during pregnancy on maternal, perinatal, and neonatal outcomes. A total of 70 studies, involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes, were included in the review. The overall risk of bias was mixed and it was noted that nearly half the studies included women who had an increased/high risk for adverse maternal and birth outcomes. Research showed there was high quality evidence which revealed that both preterm birth (before 37 weeks) and early preterm birth (before 34 weeks) was reduced in women who received omega-3 long chain polyunsaturated fatty acids when compared to those who received no omega-3. There was however moderate quality evidence that taking omega-3 slightly increased the risk of giving birth after 42 weeks. When perinatal and neonatal outcomes were analysed there was moderate quality evidence that taking omega-3 possibly reduced the risk of perinatal death and possibly fewer neonatal care admissions. There was also high quality evidence showing a reduced risk of low birthweight babies but moderate quality evidence for a possible small increase in large-for-gestational age babies. Moderate quality evidence showing little or no difference in small-for-gestational age or intrauterine growth restriction was also seen. For maternal outcomes, there was insufficient evidence to determine the effects of omega-3 on induction post-term, maternal serious adverse events, maternal admission to intensive care or postnatal depression. There was however moderate quality evidence showing that the average gestational length was greater in women who received omega-3 and low quality evidence that pre-eclampsia may possibly be reduced with omega-3. For child/adult outcomes, there was low-quality to very low-quality evidence that antenatal omega-3 supplementation had little or no effect on cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour when compared to no omega-3. Omega-3 also had little effect on BMI when the child was aged 19 years. No information on the development of diabetes in the children of study individuals was available.
Middleton P et al. Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev. 2018 Nov 15;11:CD003402.