title: Maternal and umbilical cord erythrocyte omega-3 and omega-6 fatty acids and haemorheology in singleton and twin pregnancies.
abstract: BACKGROUND
  Being devoid of both nuclei and mitochondria, mature human erythrocytes provide an opportunity to study membrane structure and function outwith the restrictions of genetic control. With its unique rapid increase in vascularisation, pregnancy is considered the most opportune period in which to investigate blood rheology.
  
  
  METHODS
  Maternal and fetal (cord) bloods were retained at delivery from 32 (25 singleton and seven twin) normal pregnancies at two maternity hospitals in the Glasgow area over a nine month period. Erythrocyte fatty acid compositions were assessed by mass spectroscopy, and corresponding membrane deformabilities measured by ultrafiltration through a membrane of 5 micro m diameter pore size, to mimic placental microcirculation.
  
  
  RESULTS
  Significant direct correlations (Spearman rank) were found between erythrocyte membrane omega-3 docosahexaenoic acid concentrations and corresponding deformabilities in maternal and cord blood from both singleton and twin pregnancies, whereas greater omega-6 arachidonic acid content was associated with increased maternal membrane rigidity. Membrane concentrations of omega-3 fatty acids only correlated strongly both within and between maternal and cord bloods. Mean cord erythrocyte docosahexaenoic acid concentration was higher than maternal in singletons but lower in twins. When maternal erythrocyte concentrations exceeded about 7% (of total fatty acids), resistance to erythrocyte flow was virtually eliminated.
  
  
  CONCLUSIONS
  It may be that a greater maternal intake of docosahexaenoic acid should be encouraged in some pregnancies for optimal tissue perfusion. Fetal demand for docosahexaenoic acid may not be entirely satisfied in multiple pregnancies.
authors.affiliation: University Department of Child Health, Royal Hospital for Sick Children and Queen Mother's Hospital, Yorkhill NHS Trust, Glasgow G3 8SJ, Scotland, UK.
authors.forename: M
authors.initials: M
authors.lastname: McFadyen
authors.forename: J
authors.initials: J
authors.lastname: Farquharson
authors.forename: F
authors.initials: F
authors.lastname: Cockburn
mesh_terms: D004281:Docosahexaenoic Acids / Q000097:blood; D004907:Erythrocyte Deformability; D004910:Erythrocyte Membrane / Q000737:chemistry; D004912:Erythrocytes / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D018056:Hemorheology; D006801:Humans; D011247:Pregnancy / Q000097:blood*; D011272:Pregnancy, Multiple / Q000097:blood; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D014470:Umbilical Cord / Q000737:chemistry*
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D004281:Docosahexaenoic Acids