Vatican Favors Implanting Diseased Embryos


That is the logical conclusion of the deliberations held this week at the Vatican during an international congress devoted to "the human embryo prior to implantation, scientific aspects and bioethical considerations." Among other questions, the conference delved into the issue of the moral status of IVF embryos discarded by would-be parents because pre-implantation genetic diagnosis (PGD) detected genetic defects.

The Associated Press began the story this way:

Scientists told a Vatican conference Tuesday that screening embryos for disease before implanting them in in-vitro fertilization posed grave ethical problems that could ultimately result in parents choosing the type of children they want.

Presumably, parents who use PGD want children who will not suffer from dread genetic diseases such as Fanconi's anemia, cystic fibrosis, Down's syndrome, muscular dystrophy and so forth. That's a laudable moral goal.

In another story, the Associated Press also reported that according to Pope Benedict XVI,

embryos developed for in vitro fertilization deserve the same right to life as fetuses, children and adults and that that right extends to embryos even before they are transferred into a woman's womb.

But a naturally produced embryo's "right to life" is empirically pretty tenuous. As I pointed out in my column "Is Heaven Populated Chiefly by the Souls of Embryos?" a while back:

John Opitz, a professor of pediatrics, human genetics, and obstetrics and gynecology at the University of Utah, testified before the President's Council on Bioethics that between 60 and 80 percent of all naturally conceived embryos are simply flushed out in women's normal menstrual flows unnoticed. This is not miscarriage we're talking about. The women and their husbands or partners never even know that conception has taken place; the embryos disappear from their wombs in their menstrual flows.

In fact, according to Opitz, embryologists estimate that the rate of natural loss for embryos that have developed for seven days or more is 60 percent. The total rate of natural loss of human embryos increases to at least 80 percent if one counts from the moment of conception. About half of the embryos lost are abnormal, but half are not, and had they implanted they would probably have developed into healthy babies.

I think that it's pretty hard to assert that human beings should be more careful of embryos than is Nature or, for believers, Nature's God.