Assisted conception services in the UK have been subject to state regulation since 1991. One of the key, if controversial, requirements of the Human Fertilisation and Embryology Act forbids the provision of 'treatment services' to a woman 'unless account has been taken of the welfare of any child who may be born as a result of the treatment (including the need of that child for a father) and of any other child who may be affected by the birth' (Section 13 (5)). In practice, fertility clinics have found it difficult to operationalise this requirement and critics have complained that it has been used to discriminate against (mostly) women and (occasionally) heterosexual couples. In 2006, the UK statutory regulator, the Human Fertilisation and Embryology Authority (HFEA), revised its guidance to fertility clinics on undertaking Section 13(5) 'welfare assessments'. The government has also indicated its intention to remove reference to a child's need for a father as part of its proposed overhaul of the Act. This paper uses a social constructionist perspective to examine the revised requirements to take account of the welfare of the child and argues that welfare assessments should be underpinned by 'respectful uncertainty' and 'healthy scepticism'.