[Methods of natural and voluntary sex selection. Value for the prevention of sex-linked malformations and of certain recurrent abortions].

Voluntary selection of the sex of a foetus may have an undeniable value in the prevention of certain diseases of malformations which are sex-linked. An indirect statistical control of the efficiency of these methods was carried out on 100 sterile treated couples. These couples agreed to respect a certain number of parameters which constitute the methods of voluntary selection of the sex of the foetus. Under these conditons and taking care that we were dealing only with cases where the sperm cell count was normal, the results were positive in 77%. It is probable the the results would have been above 80% if the parameter of the low pH of the vagina had been used as well. Attention was then directed to the possibility of using these methods to prevent certain sex-linked congenital malformations on the one hand (a classical idea) and prevention of certain repeated abortions on the other hand (a less well accepted idea). Three characteristic case histories have been reported to support these hypotheses.