Commentary

Hippocrates believed that the womb was connected to the digestive tract and thence to the mouth and nose. He probably believed this because “the first complaint attending pregnancy is the nausea and vomiting, which begins soon after conception, and frequently continues ’till the end of the fourth month.”¹ The problem, recognised for 4 millennia or more, afflicts 50−90% of pregnant women, but its cause and metabolic purpose, if any, remain unknown.

Although nausea and vomiting are normal pregnancy symptoms and signs in most situations, they are obnoxious and potentially disabling. The search for effective remedies has been confounded by the need to treat during embryogenesis, unknown causation, social and psychological influence of the condition, substantial placebo effect, and the spectre of legal action.^2,3

The review by Jewell and Young summarises an unfortunately heterogeneous assortment of 23 trials “of variable quality” of interventions for NVP. Most drugs reduced NVP better than did placebo; however, the evidence favouring acupressure and ginger was weak, and no intervention was better than placebo for hyperemesis.

Bendectin was withdrawn by its manufacturer because of exhaustive defence costs against liability suits for fetal defects (all defences were successful). Yet its ingredients, doxylamine and vitamin B-6, are among the few medications classified as “risk factor A” drugs (ie, controlled studies in women fail to show risk to the fetus in the first trimester, no evidence exists for risk in later trimesters, and the possibility of fetal harm remains remote).⁴ Because no credible evidence of human or animal teratogenesis or other undesirable effects existed, a Canadian company began to make a generic form of doxylamine-pyridoxine (Diclectin) in 1984. Thus, the pharmacological equivalent of Bendectin has been available, to the benefit of pregnant women at least in Canada, since shortly after the original formulation was withdrawn.