Epidemiological challenges to measuring prenatal cannabis use and its potential harms

In this issue of BJOG, Singh and colleagues present a scoping review of prevalence and outcomes of prenatal recreational cannabis use in high-income countries (Singh et al. BJOG xxxx). They synthesize 41 studies which confirm that up to 1 in 10 women use cannabis in pregnancy, with higher rates in the first trimester. The data also suggest that the prevalence has increased in recent years, and medical and recreational use is now legal in many jurisdictions. It seems that cannabis use will continue to be a concern in pregnancy as a result of its increased availability and social acceptability.