Global Comparison of Erythrocyte EPA and DHA Levels in Pregnant Women

BACKGROUND: Adequate levels of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are critical for maternal health and fetal development during pregnancy. Despite their importance, global data on maternal EPA+DHA blood levels remain sparse and inconsistent, partially due to differences in measurement methodologies.

OBJECTIVE: To assess global maternal EPA+DHA blood levels during pregnancy by synthesizing data from observational studies and randomized controlled trials from the last 20 years (2004 to 2025).

METHODS: Non-RBC-based EPA+DHA blood levels from published studies were standardized using conversion equations to estimate relative EPA+DHA percentages in red blood cells (estimated omega-3 index = eO3I). Country mean eO3I levels were classified into four categories based on literature-defined thresholds.

RESULTS: An analysis of 66 studies involving 33,390 pregnant women from 28 countries revealed significant geographical disparities in eO3I levels. Only the Seychelles, Norway and Ghana achieved desirable levels (>8%). Some Asian countries (Japan, Taiwan, Singapore), Malawi, Tanzania, and Northern European nations (Belgium, Netherlands, Iceland, Denmark, Sweden) exhibited sufficient/moderate levels (>6 to 8%). Most countries, including the USA, Canada, Mexico, Brazil Chile, Australia, the United Kingdom, Germany, Switzerland, Italy, Croatia, and Spain, demonstrated insufficient/low levels (>4 to 6%). Meanwhile, China, India, and Iran showed very low/undesirable levels (≤4%).

CONCLUSIONS: These findings highlight widespread insufficiency in maternal EPA+DHA status globally, with particularly severe deficiencies observed in Asia and parts of Europe. This study underscores the need for more research to ultimately define the optimal EPA+DHA levels during pregnancy using standardized blood biomarkers, along with pregnancy-specific reference ranges, to facilitate targeted nutritional strategies aimed at optimizing health outcomes for both mother and child. Future studies should focus on addressing data gaps, refining intake recommendations, and promoting accessible supplementation strategies.