In the UK, regulation of clinical services is being restructured. We consider two clinical procedures, abortion and IVF treatment, which have similar ethical and political sensitivities. We consider factors including the law, licensing, inspection, amount of paperwork and reporting requirements, the reception by practitioners and costs, to establish which field has the greater ‘regulatory burden’. We test them based on scientific, ethical, social, political factors that might explain differences. We find that regulatory burden borne by IVF services is greater than (...) in abortion, but none of the explanatory theses can provide a justification of this phenomenon. We offer an alternative explanation based on regulatory ‘overspill’ from research regulation and policy making, conceptualisation of risk regulation and a high public profile that locks a regulator into self-preservation. (shrink)