Sodium valproate in pregnancy: what are the risks and should we use a shared decision-making approach?

Alastair Macfarlane, Trisha Greenhalgh

Despite significant teratogenic risks, sodium valproate is still widely prescribed in many countries to women of childbearing age, as a mood stabiliser in bipolar disorder and also in epilepsy. The UK has recently banned valproate use in women who are not in a pregnancy prevention programme. Whilst this ruling reflects prevailing clinical practice, it also highlights an ongoing debate about when (if ever) a woman who is or could become pregnant should be allowed to choose to take valproate. We review the benefits and harms of drugs available for bipolar disorder and epilepsy in women of childbearing age, with a particular focus on teratogenic risk. We speculate on hypothetical rare situations in which potential benefits of valproate may outweigh potential harms in such women. We also review the literature on shared decision-making - on which there is now a NICE guideline and numerous evidence-based decision tools. Drawing on previous work by experts in shared decision-making, we offer a list of 'frequently asked questions' and a matrix of options to support conversations with women about continuing or discontinuing the drug in (or in anticipation of) pregnancy. We also consider whether shared decision-making is an appropriate paradigm when considering whether to continue a teratogenic drug. We conclude that because valproate in pregnancy remains the subject of such debate, there is scope for further research - not only into the relative efficacy and safety of alternatives to it - but also into the dynamics of communication and shared decision-making in this situation.