Relation between birth order and the maternal and neonatal docosahexaenoic acid status.

Department of Human Biology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.

OBJECTIVE: To investigate whether succeeding pregnancies will affect the maternal and neonatal docosahexaenoic acid (DHA, 22:6n-3) status. DESIGN: Cross-sectional study. SUBJECTS: Women who were pregnant for the 1st to 7th time and took part in a longitudinal study to investigate the essential fatty acid status of pregnant women and their infants. The total study population comprised 98 primigravidae (PG) and 146 multigravidae (MG). MAIN OUTCOME MEASURES: Fatty acid profiles of phospholipids isolated from maternal plasma samples collected during pregnancy and after delivery, and of umbilical plasma, vein and artery, obtained immediately after birth. RESULTS: The absolute (mg/L) and relative (% of total fatty acids) amounts of DHA in maternal plasma phospholipids (PL) were significantly lower in MG than in PG. In addition, a significant negative correlation was observed between gravida number and the DHA content in maternal plasma samples. The DHA deficiency index (22:5n-6/22;4n-6) was significantly higher and the DHA sufficiency index (22:6n-3/22:5n-6) was significantly lower in umbilical plasma of infants born of MG than in that of infants born of PG. The relative DHA content of umbilical artery and vein vessel walls was significantly lower in MG- than in PG-neonates and significant negative associations were observed between birth order and the relative amounts of DHA in cord tissues. CONCLUSIONS: These results indicate that the maternal DHA status becomes reduced after each following pregnancy, which may result in a lower neonatal DHA status. Whether or not this has also functional consequences needs to be investigated further.