RT Journal Article SR Electronic T1 The regulatory cliff edge between contraception and abortion: the legal and moral significance of implantation JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP 762 OP 765 DO 10.1136/medethics-2015-102712 VO 41 IS 9 A1 Sally Sheldon YR 2015 UL http://jme.bmj.com/content/41/9/762.abstract AB In regulating the voluntary interruption of pregnancy, English law has accorded particular significance to two biological events. First, ‘viability’, the moment when a fetus is said to acquire the capacity for independent life, plays an important role in grounding restrictions on access to legal abortion later in pregnancy. Second, equally significantly but far less frequently discussed, ‘implantation’ marks the point in pregnancy from which abortion laws apply. This paper focuses on this earlier biological event. It suggests that an unquestioning reliance on implantation as marking an appropriate moment of transition between two radically different legal frameworks is deeply problematic and is rendered still less sustainable in the light of the development of new technologies that potentially operate shortly after the moment of implantation.