The technique of in vitro fertilization is not the same as comprehensive testing during pregnancy, and a foetus produced by artificial fertilization can suffer any of the defects which may affect a naturally fertilized child, including Down's syndrome which results from a chromosomal mutation.
試管嬰兒的操作技術，並不等於周延的產前檢查，因此任何自然受孕胎兒可能發生的危險，經由人工生殖仍然會發生，其中包括因染色體突變引起的唐氏症。