Fatty Acid Composition of the Erythrocyte Membranes Varies between Early-Term, Full-Term, and Late-Term Infants in Japan.

BACKGROUND: Term infants can be categorized into 3 sub-groups: early term (37w0d to 38w6d), full term (39w0d to 40w6d), and late term (41w0d and beyond). However, the fatty acid composition among the 3 groups of term infants has not been investigated. The association between fatty acid composition and gestational period of term infants in Japan is unclear.

METHODS: We assessed the fatty acid composition of maternal erythrocyte membranes in the third trimester and of cord erythrocyte membranes at birth in 212 healthy term Japanese infants using data from a prospective hospital-based cohort study.

RESULTS: In maternal erythrocyte membranes, docosahexaenoic acid (DHA) levels and omega-3 index were significantly higher in the late-term group than in the early-term group. In cord erythrocyte membranes, DHA levels were not significantly different between the 3 groups; late-term infants showed significantly higher DHA/arachidonic acid (ARA) and lower 20: 3n-6 and ARA levels compared to early-term infants. Gestational period positively correlated with the DHA status in maternal and cord erythrocyte membranes.

CONCLUSIONS: Fatty acid composition in maternal and cord erythrocyte membranes varies between early-, full-, and late-term infants, and the greater gestational period may contribute to the relatively high n-3 polyunsaturated fatty acids status in term infants. Furthermore, maternal DHA status in the third semester directly correlates with gestational period in pregnant Japanese women.