Biotin deficiency is teratogenic in several mammalian
species. Approximately 50% of pregnant women have an
abnormally increased urinary excretion of 3-hydroxyisovaleric acid
(3-HIA), which probably reflects decreased activity of the biotindependent
enzyme methylcrotonyl-CoA carboxylase. However,
increased 3-HIA excretion could result from pregnancy per se (eg,
from an effect of pregnancy on renal handling of organic acids).
Objective: We tested the hypothesis that biotin supplementation
significantly decreases 3-HIA excretion in pregnant women with
abnormally increased 3-HIA excretion.