Adding omega-3 fatty acids to the diet during pregnancy.
Does taking omega-3 long-chain polyunsaturated fatty acids (LCPUFA) supplements or increasing the intake of certain foods (such as certain types of fish) during pregnancy help improve health outcomes for women and their newborns? This is an update of the Cochrane Review, first published in 2006..
Why is it important?
Premature birth (babies born before 37 weeks of gestation (gestation)) is the leading cause of disability or death in the first five years of life. Fish and fish oils contain omega-3 LCPUFAs (specifically, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) and are associated with longer pregnancies. Thus, it is suggested that supplementation with omega-3 LCPUFA during pregnancy may reduce the number of preterm infants and improve outcomes for children and mothers. However, many pregnant women do not eat fish as often.
Encouraging pregnant women to eat oily fish (which are usually low in toxins) or supplements with omega-3 LCPUFA can improve the health of women and their children. This is an update of the Cochrane Review, first published in 2006..
What evidence did we find?
We searched for evidence in August 2018 and found 70 randomized controlled trials (RCTs; this type of trial provides the most reliable results) in 19,927 women. The authors of most of the trials studied a group of women who took omega-3 LCPUFA and compared them with a group of women who took a placebo or who did not take omega-3 at all. A placebo is something similar to the omega-3 LCPUFA but does not contain the omega-3 LCPUFA. These clinical trials have mainly been conducted in middle- or high-income countries.
Some studies have included women with an increased risk of preterm birth. The quality of the evidence from the included studies ranged from high to very low. This affected the validity of the results for different outcomes..
We found that the rates of preterm birth (up to 37 weeks) and early preterm birth (up to 34 weeks) were lower in women taking omega-3 LCPUFAs compared with women who did not take omega-3 supplements. Also, women taking omega-3 LCPUFAs had fewer low birth weight babies. However, omega-3 LCPUFAs likely increased the frequency of pregnancies lasting more than 42 weeks. Despite this, no differences were found in the induction of labor in post-term pregnancies.
The risk of a baby dying or being very ill and admitted to neonatal intensive care may be lower in women
who took the omega-3 LCPUFA during pregnancy compared to women who did not take omega-3s. We did not find any differences between groups for serious adverse events for mothers or postpartum depression. There was very little difference in the development and growth of children between the groups of women who took omega-3 LCPUFA during pregnancy and women who did not take omega-3.
The authors of eleven trials reported that they received industry funding. We excluded these studies from evaluating key outcomes (such as preterm labor and early preterm labor), this did not change the results or made very little change..
What does it mean?
Increasing your intake of omega-3 LCPUFAs during pregnancy through dietary supplements or certain foods can reduce the incidence of preterm birth (up to 37 weeks and up to 34 weeks). Also, if the intake of omega-3 LCPUFAs increases during pregnancy, women may be less likely to have a low birth weight baby. Women who take omega-3 LCPUFA supplements may also have longer pregnancies.
Additional studies are underway and the results will be included in a further update of this review. Future research could consider whether, and if so, how results might differ in different populations of women. You could also try different ways to increase your intake of omega-3 LCPUFAs during pregnancy..