Should doxylamine-pyridoxine be used for nausea and vomiting of pregnancy?

Doxylamine-pyridoxine is the first-line agent for the treatment of nausea and vomiting of pregnancy (NVP) according to Canadian guidelines, and this combination is commonly prescribed to pregnant women. There is limited evidence that doxylamine-pyridoxine is more effective than pyridoxine alone. There is stronger support for the safety of pyridoxine monotherapy than for the combination of doxylamine-pyridoxine during pregnancy, and some conflicting evidence links doxylamine-pyridoxine use to pyloric stenosis and childhood malignancies. The role of doxylamine-pyridoxine as the first-line pharmacological treatment for NVP in Canada should be reconsidered.