Life and death before birth: 4D ultrasound and the shifting frontiers of the abortion debate.

The development of 4D ultrasound technology has democratised fetal imagery by offering direct visual access to realistic images of the fetus in utero. These images, which purport to show a responsive being capable of complex behaviour, have renewed debate about the personhood of the fetus and the adequacy of current abortion regulation. This article considers recent abortion law reform initiatives in the United Kingdom and the United States and observes two shifts in the frontiers of these debates. The first concerns a shift from viability to sentience as a criterion of legal significance. The second concerns a shift toward constructing abortion in terms of feticide as distinct from the termination of pregnancy. Both strategies seek to deploy morphological similarities between the sentient fetus and newborn baby as a basis for extending law's dominion over the fetus.