BackgroundThe findings of the association between maternal polyunsaturated fatty acid (PUFA) levels during pregnancy and offspring weight status are controversial. Furthermore, few studies have focused on Asian populations or used erythrocyte membranes as biological markers. We aimed to examine the associations between maternal erythrocyte PUFA and offspring weight status within the first 2 years among the Chinese population.Materials and methodsA total of 607 mother-child pairs were recruited from a birth cohort. Maternal erythrocyte n-3 and n-6 PUFA during pregnancy were measured by gas chromatography, and the ratio of PUFA was calculated. Weight- and body mass index (BMI)-for-age z (WAZ and BAZ) scores were calculated for offspring at 1, 3, 6, 8, 12, 18, and 24 months of age. The risk of overweight and obesity was defined by the WHO criterion. The Generalized Estimating Equation (GEE) model was carried out for repeated anthropometric data within 2 years of age.ResultsMaternal erythrocyte docosapentaenoic acid (DPA, n-3) was inversely associated with offspring BAZ score [tertile 2 vs. tertile 1, β: −0.18 (−0.29, −0.00)]. Higher maternal erythrocyte arachidonic acid (AA) was inversely associated with lower offspring WAZ and BAZ [tertile 3 vs. tertile 1, β: −0.18 (−0.35, −0.02), −0.22 (−0.38, −0.06), respectively]. Furthermore, higher maternal erythrocyte AA [tertile 3 vs. tertile 1, odds ratio [OR]: 0.52 (0.36, 0.75), p_trend < 0.001] and total n-6 PUFA [tertile 3 vs. tertile 1, OR: 0.56 (0.39, 0.81), p_trend = 0.002] were associated with decreased risk of overweight and obesity in offspring. Maternal erythrocyte n-6/n-3 PUFA and AA/eicosapentaenoic acid (EPA) ratios were not associated with offspring weight status.ConclusionMaternal erythrocyte PUFA might influence offspring weight status within 2 years of age in the Chinese population. Further Asian studies are still needed.