Maternal plasma homocysteine, placenta status and docosahexaenoic acid concentration in erythrocyte phospholipids of the newborn

Abstract

The enhanced transport of long-chain polyunsaturated fatty acids, in particular docosahexaenoic acid (22:6 omega-3) (DHA), to the fetus is a placental function important for adequate membrane phospholipid formation and herewith decisive for the quality of fetal CNS myelination. A compromised placental function is correlated with signs of vascular pathology. As elevated plasma total homocysteine (tHcy) concentrations are considered an independent risk for premature occlusive vascular disease, the influence of maternal plasma tHcy concentrations on placental function was indirectly studied, determining the DHA content in erythrocyte membrane phospholipids of the newborn. A total of 60 unselected pregnant women (age range: 21 to 39 years) were investigated at delivery. Gestational age ranged from 26 to 41 weeks. Prior to delivery a placental ultrasound scan was performed. Complete sets of data could be obtained from 43 mothers and their offspring. tHcy concentrations were determined in the plasma of cord and maternal blood. The fatty acid pattern of erythrocyte membrane phospholipids was determined in the mothers and their newborns. Z-scores of the birth weights ranged from -3.4 to 2.1 and of the placental weights from -3.8 to 4.7. The mean maternal plasma tHcy concentration was 6.29 +/- 3.34 micromol/l ranging from below our limit of detection up to 15 micromol/l. These maternal concentrations were correlated with those of their infants (r = 0.71; P < 0.0001). The tHcy concentrations were significantly higher in mothers with pregnancies complicated by gestosis or placental calcifications. The Z-scores of birth weights as well as placental weights showed a significant negative correlation with maternal plasma tHcy concentrations. The mean DHA percentage of total fatty acids in erythrocyte phospholipids was 3.2 +/- 2.2% in the mothers and 3.4 +/- 2.3% in their newborns. Most importantly the maternal plasma tHcy levels and the erythrocyte phospholipid DHA concentrations of their offspring were significantly correlated (r = -0.51; P < 0.0003). In this study, total homocysteine concentrations were elevated in the plasma of pregnant women with signs of placental vasculopathy. Maternal plasma total homocysteine concentrations were positively correlated with erythrocyte phospholipid docosahexaenoic acid of their offspring and may be an indicator for the integrity of placental vascular function. The nutritional status as well as predisposing genetic factors of pregnant mothers need to be investigated more thoroughly.