Alternative reproductive technology (ART) refers to medical techniques used to help people conceive other than by sexual intercourse, such as in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), donor insemination and the use of donor eggs, sperm or embryos, often in combination with surrogacy arrangements. In UK practice, the more precise statutory term is “assisted reproduction” or “treatment services” under the Human Fertilisation and Embryology Acts 1990 and 2008, which regulate the creation, storage and use of embryos and gametes and govern legal parenthood in assisted conception. In Ireland, assisted human reproduction is addressed through specific legislation and case law, with a similar focus on regulation of treatment, donation and parental status. The expression “ART” or “alternative reproductive technology” is therefore largely descriptive rather than a defined legal term, but is widely used in clinical and legal commentary. It is central to advice on legal parentage, parental responsibility, donor anonymity, consent, clinic licensing, cross‑border fertility treatment, immigration and nationality issues for children born via ART, and the drafting and enforceability of surrogacy and donor agreements across the UK and Ireland.