Since birth dimensions have prognostic potential for later development and health, possible associations between neonatal birth dimensions and selected maternal plasma fatty acid contents were investigated, using data from 782 mother–infant pairs of the Maastricht Essential Fatty Acid Birth cohort. Unadjusted and multivariable-adjusted regression analyses were applied to study the associations between birth weight, birth length or head circumference and the relative contents of DHA, arachidonic acid (AA), dihomo-γ-linolenic acid (DGLA) and 18 : 1trans (18 : 1t) in maternal plasma phospholipids sampled during early, middle and late pregnancies, and at delivery. Where appropriate, corrections were made for relevant covariables. Significant ‘positive’ associations were observed between maternal DHA contents (especially early in pregnancy) and birth weight (B = 52·10 g, 95 % CI 20·40, 83·80) and head circumference (B = 0·223 cm, 95 % CI 0·074, 0·372). AA contents at late pregnancy were ‘negatively’ associated with birth weight (B = − 44·25 g, 95 % CI − 68·33, − 20·16) and birth length (B = − 0·200 cm, 95 % CI − 0·335, − 0·065). Significant ‘negative’ associations were also observed for AA contents at delivery and birth weight (B = − 27·08 g, 95 % CI − 47·11, − 7·056) and birth length (B = − 0·207 cm, 95 % CI − 0·330, − 0·084). Maternal DGLA contents at delivery were also significantly ‘negatively’ associated with neonatal birth weight (B = − 85·76 g, 95 % CI − 130·9, − 40·61) and birth length (B = − 0·413 cm, 95 % CI − 0·680, − 0·146). No significant associations were observed for maternal 18 : 1t contents. We conclude that during early pregnancy, maternal DHA content may programme fetal growth in a positive way. Maternal AA and DGLA in late pregnancy might be involved in fetal growth limitation.