BACKGROUND: Hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) 
gene mutation have been postulated as a possible cause of recurrent miscarriage 
(RM). There is a wide variation in the prevalence of MTHFR polymorphisms and 
homocysteine (Hcy) plasma levels among populations around the world. The present 
study was undertaken to investigate the possible association between 
hyperhomocysteinemia and its causative genetic or acquired factors and RM in 
Catalonia, a Mediterranean region in Spain.
METHODS: Sixty consecutive patients with ≥ 3 unexplained RM and 30 healthy 
control women having at least one child but no previous miscarriage were 
included. Plasma Hcy levels, MTHFR gene mutation, red blood cell (RBC) folate 
and vitamin B12 serum levels were measured in all subjects.
RESULTS: No significant differences were observed neither in plasma Hcy levels, 
RBC folate and vitamin B12 serum levels nor in the prevalence of homozygous and 
heterozygous MTHFR gene mutation between the two groups studied.
CONCLUSIONS: In the present study RM is not associated with 
hyperhomocysteinemia, and/or the MTHFR gene mutation.