Do all pregnant women need an omega-3 supplement?

Updated on: Apr 19, 2016

No. An omega-3 supplement is not recommended for all pregnant women. A full evaluation by a nutritionist of the diet and risk factors in the mother is required to assess the suitability of using such a supplement.

A fish oil supplement should not be considered an alternative to the consumption of fish or omega-3 rich food. For more information on omega-3 in food, click here. As with all supplements, omega-3 intake should be assessed and monitored by a healthcare professional, considering all the impacts this may have on the pregnant woman’s health.

In recent years, particular interest has been taken on omega-3 and its possible beneficial impact in reducing the risk of certain health conditions during pregnancy, such as premature delivery *, problems with the child’s neurological development, low birth weight, preeclampsia, gestational diabetes or postpartum depression. Following a review of the different studies on the subject, it is to remember that:

  • There is a real benefit on the neurological development of the fetus when consuming omega-3 in the form of fish during pregnancy. To learn more about what types of fish to choose during pregnancy, click here.
  • Positive effects have not been demonstrated for the conditions mentioned above (*) when taking an omega-3 supplement.
  • In the case of a high-risk pregnancy, taking an omega-3 supplement would have little positive effect on the birth weight and the risk of prematurity, but further studies are necessary.
  • In most pregnancies, there are no benefits to taking an omega-3 supplement, but there is no inconvenience or risks for the pregnant woman or the child.

The consumption of fish seems to be the most beneficial health wise. Although more research is needed to fully understand the mechanism, it could be that it is the combination of omega-3 with other nutrients in fish that is most favorable.

At the Montreal Diet Dispensary, taking a fish oil supplement may be recommended as part of a treatment plan established and monitored by a nutritionist, and in some situations:

  • Low omega-3 intake: low consumption of fish, seafood and plant sources (walnuts, flaxseed, etc.).
  • High risk of preterm birth or severe restriction of intrauterine growth: history of preterm delivery, signs of early labor, important stress.
  • The presence of certain risk factors may also justify the relevance of taking an omega-3 supplement; this is to be determined by a healthcare professional. To learn more about risk factors during pregnancy, click here (article coming soon).

For women with low-risk pregnancies, there is no interest in taking an omega-3 supplement. The recommendation is to consume 200-350 g of cooked fish per week to meet the needs during pregnancy. To learn on which fish to consume during pregnancy, click here.

Although fish oil supplements are relatively safe during pregnancy, they are not recommended for pregnant women who present with bleeding or who take anticoagulants (a blood thinner) such as Coumadin or Heparin. Cod liver oil is also not recommended for all pregnant women due to its high vitamin A content. For more information on the effects of vitamin A on the fetus, click here. For information on how to choose an omega-3 supplement, click here. In all cases, before choosing a supplement, consult a pharmacist and/or a healthcare professional.


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