Effect of alpha-linolenic acid supplementation during pregnancy on maternal and neonatal polyunsaturated fatty acid status and pregnancy outcome.

BACKGROUND Maternal essential fatty acid status declines during pregnancy, and as a result, neonatal concentrations of docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) may not be optimal. OBJECTIVE Our objective was to improve maternal and neonatal fatty acid status by supplementing pregnant women with a combination of alpha-linolenic acid (ALA, 18:3n-3) and linoleic acid (LA, 18:2n-6), the ultimate dietary precursors of DHA and AA, respectively. DESIGN From week 14 of gestation until delivery, pregnant women consumed daily 25 g margarine supplying either 2.8 g ALA + 9.0 g LA (n = 29) or 10.9 g LA (n = 29). Venous blood was collected for plasma phospholipid fatty acid analyses at weeks 14, 26, and 36 of pregnancy, at delivery, and at 32 wk postpartum. Umbilical cord blood and vascular tissue samples were collected to study neonatal fatty acid status also. Pregnancy outcome variables were assessed. RESULTS ALA+LA supplementation did not prevent decreases in maternal DHA and AA concentrations during pregnancy and, compared with LA supplementation, did not increase maternal and neonatal DHA concentrations but significantly increased eicosapentaenoic acid (20:5n-3) and docosapentaenoic acid (22:5n-3) concentrations. In addition, ALA+LA supplementation lowered neonatal AA status. No significant differences in pregnancy outcome variables were found. CONCLUSIONS Maternal ALA+LA supplementation did not promote neonatal DHA+AA status. The lower concentrations of Osbond acid (22:5n-6) in maternal plasma phospholipids and umbilical arterial wall phospholipids with ALA+LA supplementation than with LA supplementation suggest only that functional DHA status improves with ALA+LA supplementation.