In the 1970s, Puxon switched interests from family law to medical negligence, typically representing plaintiffs; her dual qualifications in medicine and law gave her a niche advantage in this area. She provided advice to Bourn Hall Clinic, an infertility clinic, about the wording of consent contracts for sperm and egg donors. When the Family Planning Association was threatened with legal action, they consulted Puxon about whether the prescription of the morning-after pill was equivalent to providing an abortion; Puxon advised that if the pill was used within 72 hours, its use did not amount to abortion by the meaning of the law because the ovum had not yet implanted in the wall of the uterus.
