The case presented here involves recurrent anencephalies and so-called sex selection, a method applied to dispel anxiety about a third pregnancy in a couple free from hereditary predisposition to births with congenital malformation of the central nervous system. Sex selection, a method used to obtain a male rather than a female, is widely practiced in Japan. However, not only are the details of this method kept secret, but the members of the Sex Selection Society also have a monopoly on the drug administered. Statistical analysis of the recurrent incidence of anencephaly is not available in Japan, but the frequency seems to be extremely low according to reports in other countries. Anencephaly is clearly not a sex-linked malformation, although its etiology is still disputed. The problems entailed in sex selection, especially when decided only by the couple's wish and unethical judgement of clinicians, are discussed in detail.