title: Folate and vitamin B12 concentrations in maternal and fetal blood, and amniotic fluid in second trimester pregnancies complicated by neural tube defects.
abstract: OBJECTIVE
  To investigate maternal and fetal folate and vitamin B12 concentrations in pregnancies affected by neural tube defects (NTD).
  
  
  METHODS
  Measurement of folate and vitamin B12 concentrations in amniotic fluid, fetal blood and maternal blood samples in midgestation.
  
  
  METHODS
  32 women undergoing termination of pregnancy at 14-21 weeks gestation for social reasons (n = 24) or for fetuses with neural tube defects (n = 8).
  
  
  METHODS
  Fetoscopy before intra-amniotic injection of prostaglandins.
  
  
  RESULTS
  In normal pregnancies there was a positive correlation between maternal and fetal serum folate, and the fetal serum and red blood cell folate concentrations were higher than the maternal. There were no differences in amniotic fluid, maternal blood or fetal blood folate concentrations between pregnancies with NTD and normal pregnancies. Although amniotic fluid vitamin B12 was lower in pregnancies with NTD, maternal serum vitamin B12 concentration was not reduced.
  
  
  CONCLUSIONS
  In this small group of pregnancies with NTD at mid-gestation there is no evidence to suggest folate or vitamin B12 deficiency.
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, Churchill Hospital, Headington, Oxford.
authors.forename: D L
authors.initials: DL
authors.lastname: Economides
authors.forename: J
authors.initials: J
authors.lastname: Ferguson
authors.forename: I Z
authors.initials: IZ
authors.lastname: Mackenzie
authors.forename: J
authors.initials: J
authors.lastname: Darley
authors.forename: I I
authors.initials: II
authors.lastname: Ware
authors.forename: M
authors.initials: M
authors.lastname: Holmes-Siedle
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood; D000653:Amniotic Fluid / Q000737:chemistry*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005492:Folic Acid / Q000032:analysis* / Q000097:blood; D006801:Humans; D009436:Neural Tube Defects / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood*; D011262:Pregnancy Trimester, Second; D014805:Vitamin B 12 / Q000032:analysis* / Q000097:blood
chemical_list: D005492:Folic Acid; D014805:Vitamin B 12