title: Low serum vitamin B12 is associated with recurrent pregnancy loss in Syrian women.
abstract: BACKGROUND
  Hyperhomocysteinemia and B-vitamin deficiency are associated with recurrent abortion. Recent studies have not investigated functional markers of vitamin B12 deficiency, such as methylmalonic acid.
  
  
  METHODS
  A total of 43 consecutive Syrian women with unexplained recurrent abortion and 32 pregnant controls were enrolled in the study. Serum folate, vitamin B12, methylmalonic acid and plasma homocysteine were determined.
  
  
  RESULTS
  Vitamin B12 was significantly decreased in patients with recurrent abortion compared to controls (mean concentrations 197 vs. 300 pg/mL, p=0.004). The lowest mean serum vitamin B12 (172 pg/mL) was observed in primary aborters. Homocysteine was elevated in aborters in comparison to controls (8.3 vs. 7.1 micromol/L, p=0.093). Folate and methylmalonic acid did not differ significantly between the study groups. A highly significant correlation between homocysteine and methylmalonic acid and vitamin B12 was observed only in patients but not in controls (p<0.001 and p=0.002, respectively). In the logistic regression model, only serum vitamin B12 emerged with a significant odds ratio.
  
  
  CONCLUSIONS
  The results confirm low serum vitamin B12 in recurrent abortion patients. However, methylmalonic acid did not support that functional vitamin B12 plays a role in this group. This unexpected result might be due to a decrease of the metabolically inert vitamin B12 fraction (holohaptocorrin) or confounding factors. Further studies are necessary to investigate the role of vitamin B12 deficiency in recurrent abortion.
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Homburg/Saar, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hübner
authors.forename: Ahmad
authors.initials: A
authors.lastname: Alwan
authors.forename: Muhidin
authors.initials: M
authors.lastname: Jouma
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tabbaa
authors.forename: Heike
authors.initials: H
authors.lastname: Schorr
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herrmann
mesh_terms: D000026:Abortion, Habitual / Q000097:blood* / Q000453:epidemiology; D000328:Adult; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D011247:Pregnancy; D013593:Syria / Q000453:epidemiology; D014805:Vitamin B 12 / Q000097:blood* / Q000378:metabolism
chemical_list: D006710:Homocysteine; D014805:Vitamin B 12