BackgroundSeveral studies suggest that low circulating levels of long‐chain omega‐3 fatty acids are associated with poor birth outcomes, however results are mixed possibly because the majority of studies have been conducted in high‐income settings.ObjectiveTo determine whether fatty acid status during pregnancy is associated with birth outcomes in Malawian women.MethodsWe performed a nested cohort study (n=315) of pregnant women ≤ 20 wk gestation enrolled in a large randomized controlled trial in rural Malawi. We measured plasma fatty acids (wt%) at enrollment and at 36 wk gestation. Specific fatty acids of interest included the omega‐3 fatty acids, alpha‐linolenic acid (ALA) and docosahexaenoic acid (DHA); and the omega‐6 fatty acids, linoleic acid (LA) and arachidonic acid (AA). Study nurses recorded birth size, and duration of gestation was estimated by baseline ultrasound. Linear regression and logistic regression models were used to examine the association between plasma fatty acids and birth outcomes.ResultsIn adjusted analyses, higher plasma ALA at ≤ 20 wk gestation was associated with a longer duration of gestation (β: 0.34 d/0.1%, SE: 0.22, p=0.03), greater birth weight (β: 16 g/0.1%, SE: 6.4, p=0.01), and greater head‐circumference‐for‐age z‐score (β: 0.03 SD/0.1%, SE: 0.01, p=0.04). Above median plasma ALA at ≤ 20 wk gestation was associated with a lower risk of newborn stunting (RR: 0.53, 95% CI: 0.30, 0.94, p=0.03) versus below median. Plasma ALA at 36 wk gestation was not associated with any birth outcome. Higher LA at ≤ 20 wk gestation was associated with greater weight‐for‐age (WAZ), and higher LA at 36 wk gestation with greater WAZ and head‐circumference‐for‐age z‐score. AA and DHA levels were not associated with any birth outcome.ConclusionHigher plasma ALA and LA in early pregnancy were associated with better birth outcomes, however their longer‐chain metabolites AA and DHA were not.Support or Funding InformationFunding was provided by a grant to UC Davis by The Bill & Melinda Gates Foundation.
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