6. WHAT JUDGMENT SHOULD BE MADE ON OTHER PROCEDURES OF MANIPULATING EMBRYOS CONNECTED WITH THE "TECHNIQUES OF HUMAN REPRODUCTION"? 

Techniques of fertilization in vitro can open the way to other forms of biological and genetic manipulation of human embryos, such as attempts or plans for fertilization between human and animal gametes and the gestation of human embryos in the uterus of animals, or the hypothesis or project of constructing artificial uteruses for the human embryo. These procedures are contrary to the human dignity proper to the embryo, and at the same time they are contrary to the right of every person to be conceived and to be born within marriage and from marriage.(³²) Also, attempts or hypotheses for obtaining a human being without any connection with sexuality through "twin fission", cloning or parthenogenesis are to be considered contrary to the moral law, since they are in opposition to the dignity both of human procreation and of the conjugal union. 

The freezing of embryos, even when carried out in order to preserve the life of an embryo - cryopreservation - constitutes an offence against the respect due to human beings by exposing them to grave risks of death or harm to their physical integrity and depriving them, at least temporarily, of maternal shelter and gestation, thus placing them in a situation in which further offences and manipulation are possible. 

Certain attempts to influence chromosomic or genetic inheritance are not therapeutic but are aimed at producing human beings selected according to sex or other predetermined qualities. These manipulations are contrary to the personal dignity of the human being and his or her integrity and identity. Therefore in no way can they be justified on the grounds of possible beneficial consequences for future humanity. (³³) Every person must be respected for himself: in this consists the dignity and right of every human being from his or her beginning.