Research Glimpse: Various healthcare strategies have been employed to try and prevent preterm delivery (especially before 34-37 weeks of gestation) because preterm births represent one of the key factors resulting in infant morbidity and mortality and health challenges later in life. Several studies have reported that a higher intake of fish/seafood, a major dietary source of DHA (docosahexaenoic acid) plus EPA (eicosapentaenoic acid), during pregnancy was associated with a lower frequency of intrauterine growth retardation as well as benefiting neurocognitive development in childhood (Nutr. Rev., 73 Suppl. 3: 154-174 (2015)). Since there have been a number of isolated clinical trials which have evaluated the potential for supplementation with omega-3 LCPUFA as DHA/EPA omega-3 fatty acids to improve pregnancy outcomes, this recent analysis from the Cochrane Pregnancy and Childbirths Trials Register provides an extensive and updated review of this important topic. In this update, 70 randomized clinical trials were included (involving 19,927 women at low, mixed, or high risk of poor pregnancy outcomes) which compared omega-3 LCPUFA interventions (via supplements and enriched food sources) versus placebo or no omega-3 LCPUFA.
The Cochrane review reported an overall 11 % lower risk for preterm birth before 37 weeks (13.4 % versus 11.9 %) and a 42 % lower risk for early preterm birth before 34 weeks (4.6 % versus 2.7 %) in the infants from mothers who received omega-3 LCPUFA as compared to those who did not. The review also indicated that omega-3 LCPUFA intakes yielded a possible reduced risk of perinatal death and of neonatal care admission.
It is noted that, in the study by Makrides et al. from Australia (J. Am. Med. Assoc., 304: 1675-1683 (2010)), the daily omega-3 supplemental dose consisted of 800 mg DHA plus 100 mg EPA which, in addition to reducing premature births, lowered infant admissions to intensive care by 45 % relative to the controls not receiving the omega-3 fatty acids. A later US-based study by Carlson et al. (Am. J. Clin. Nutr., 97: 808-815 (2013)) targeted supplemental DHA omega-3 at 600 mg/day (actual intakes determined to be 469 mg/day) and found a marked lowering in the prevalence of shortened gestations (< 34 weeks) and reductions in premature births. Infants of mothers who received the omega-3 supplements had a 80 % reduction in intensive care admissions and 82 % fewer preterm infant days in hospital as compared to infants of mothers not receiving omega-3 supplementation. It is noted that typical intakes of DHA plus EPA from dietary sources in these two countries are in the range of only 110-150 mg/day. Published research from our lab (J. Nutrition, 135: 206-211 (2005)) on pregnant Canadian women determined the average daily intake/person from dietary sources to be only 82 mg DHA plus 35 mg EPA.
Clinical conclusion: This updated review indicates that, as with folic acid supplementation during pregnancy (to prevent infant neural tube defects), a universal strategy of omega-3 LCPUFA supplementation with certified DHA-enriched products during pregnancy to reduce early preterm birth along with other health benefits needs serious consideration along with special attention to those women who might benefit even more. The very low intake of fish/seafood averages approximately one serving every 7-10 days in North America (due in part to public concerns regarding environmental contaminants). Thus, the DHA/EPA intakes fall well short of the omega-3 LCPUFA amounts as employed in the aforementioned clinical trials. The cost for such supplementation is generally low and can be expected to provide large financial savings to the health care system along with the reductions in preterm births and other health benefits in infancy and well into childhood.
Middleton, P. et al., Cochrane Database of Systematic Reviews, Issue 11, Art. No. CD003402 (Nov., 2018)