Fetal Uptake of DHA is a High Priority
Objective: We assessed distribution and human placental transfer of 13C-labeled fatty acids (FAs) 12 h after oral application.
Design: Eleven pregnant women received 0.5 mg [13C]palmitic acid (13C-PA; 16:0), 0.5 mg [13C]oleic acid (13C-OA; 18:1n–9), 0.5 mg [13C]linoleic acid (13C-LA; 18:2n–6), and 0.1 mg [13C]docosahexaenoic acid (13C-DHA; 22:6n–3) per kilogram of body weight orally 12 h before elective cesarean section. Maternal blood samples were collected before tracer intake (–12 h) and at –3, –2, –1, 0, and +1 h relative to the time of cesarean section. At birth, venous cord blood and placental tissue were collected, and FA concentrations in individual lipid fractions and their tracer content (atom percent excess values) were determined.
Results: Relatively stable tracer enrichment was achieved in maternal lipid fractions 12 h after tracer administration. In maternal plasma, most 13C-PA and 13C-OA were found in triglycerides, whereas 13C-LA and 13C-DHA were found mainly in plasma phospholipids and triglycerides. In placental tissue, 13C-FAs were mainly found in phospholipids, which comprise 80% of placental tissue lipids. Placenta-maternal plasma ratios and fetal-maternal plasma ratios for 13C-DHA were significantly higher than those for any other FA.
Conclusions: Twelve hours after oral application of 13C-labeled FAs, relatively stable tracer enrichment was achieved. We found a significantly higher ratio of 13C-DHA concentrations in cord plasma than in maternal plasma, which was higher than that for the other studied FAs. 13C-DHA is predominantly esterified into phospholipids and triglycerides in maternal plasma, which may facilitate its placental uptake and transfer.
Alfonso Gil-Sánchez, Elvira Larqué, Hans Demmelmair, María I Acien, Fabienne L Faber, Juan J Parrilla and Berthold Koletzko
Maternal-fetal in vivo transfer of [13C]docosahexaenoic and other fatty acids across the human placenta 12 h after maternal oral intake.
Am J Clin Nutr
Service of GynecologyObstetrics Hospital Vírgen de la Arrixaca Murcia Spain.