USE OF PYRIDOXINE (VITAMIN B6) IN PREGNANCY

Pyridoxine (vitamin B6) is an essential vitamin. It is converted to pyridoxal-5’-phosphate which is the co-enzyme for a variety of metabolic transformations. Pyridoxine is used at varying doses in the treatment of nausea and vomiting of pregnancy (NVP), isoniazid-induced peripheral neuritis, idiopathic sideroblastic anaemia and vitamin B6 deficiency states.

The majority of human pregnancy data relate to use of pyridoxine in combination with doxylamine in the treatment of NVP. Rates of infant congenital malformation following in utero exposure to products containing this combination of drugs have been widely studied, with the majority of analyses providing no evidence of an increased risk. No increased risk of miscarriage has been observed following gestational pyridoxine exposure. No association with low birth weight, preterm delivery, intrauterine death or neonatal complications has been identified, although data are too limited to exclude an increase in risk.

Exposure to pyridoxine at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy or any additional fetal monitoring. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.