For more than 35 years, there has been broad international agreement that no scientist can experiment on an embryo that is more than 14 days old. This red line was established as scientific guidance in the United States in 1979, and it was incorporated into British law after the 1984 Warnock inquiry into in vitro fertilization. Other nations, including Australia, Sweden and China, have since adopted the same limit, either in law or through scientific regulation.
Rethinking Embryo Research Rules
