Gestational diabetes mellitus enhances arachidonic and docosahexaenoic acids in placental phospholipids

In previous studies, we reported that neonates of women with gestational diabetes mellitus (GDM) have reduced blood levels of arachidonic acid (AA) and docosahexaenoic acid (DHA) that were unrelated to maternal status. Since both AA and DHA are selectively transferred from maternal to fetal circulation by the placenta, we have investigated whether the FA composition of the placenta is altered by GDM. Thirty-six women, 11 with and 25 without GDM, were recruited from Newham General Hospital, London. The women with GDM had higher levels of di-honio-y-linolenic (P < 0.05), docosatetraenoic (n-6 DTA; P < 0.0001), docosapentaenoic n-6 (P < 0.005), total n-6 (P < 0.005), docosapentaenoic (n-3 DPA; P < 0.005), and total n-3 (P < 0.01) FA, as well as higher levels of AA (P < 0.05) and DHA (P < 0.01), in placental choline phosphoglycerides (CPG) compared with the healthy women who served as controls. Similarly, the women with GDM had elevated n-6 DTA (P < 0.005), AA, total n-6 metabolites (P < 0.05), DHA, total n-3 metabolites, and total n-3 FA (P < 0.005) in ethanolamine phosphoglycerides (FPG). In contrast to CPG and EPG, the placental TG of the women with GDM had higher linoleic acid (P < 0.05) and lower AA, n-6 metabolites, and n-3 DPA (P < 0.01). The placenta is devoid of desaturase activity, and it is thought to be reliant on maternal circulation for both AA and DHA. Hence, the enhanced levels of the two FA in the placenta of the GDM group suggests that these FA are taken up from the maternal circulation and retained after esterification into phosphoglycericles instead of being transferred to the fetus. Further study is needed to elucidate the mechanism involved and the effect of the phenomenon on postnatal growth and development of the offspring.