Although nearly 99% of abortions in New Zealand are permitted in order to prevent danger or injury to a woman’s mental health (the ‘mental health exception’), the reasons why mental health considerations should effectively control access to abortion are not altogether clear. This article analyses abortion case law, statutes and debates from New Zealand, the United Kingdom and the United States to attempt to explain the legal connection between mental health considerations and access to abortion. The article argues that the (...) mental health exception evolved in response to a change in the predominant construction of women seeking abortion from ‘selfish’ to ‘desperate’, coinciding with increasing societal subscription to an expanded view of psychological harm. By conceptually accommodating both constructions of women seeking abortion, the article argues that the mental health exception usefully enabled society generally to proscribe the practice of abortion on the basis that it was unnatural and irrational, while nevertheless permitting it in cases considered to be deserving. (shrink)