Reacting to a news item that appeared on Thursday 23 May in the Swiss newspaper Basler Zeitung, Basle University Hospital confirmed that parents who are carriers of serious hereditary diseases "can henceforth choose the sex of their baby" with an 80% reliability rate. This hospital is the only institution to propose this selection method of American origin called “Microsort”.
In concrete terms, this method is used to prevent the transmission to the child of hereditary diseases such as cystic fibrosis and muscular dystrophy, which affect only one sex. It consists of "separating the sperms whose heredity is female from those whose heredity is male" and "is based on the fact that the female X chromosomes contain a little more of the genetic heritage than the male Y chromosomes."
In Switzerland, the selection of sperm is authorised "for cases involving serious hereditary diseases passed on by one of the two parents."