A number of years ago, a couple came into the fertility practice where I worked. They were not infertile and in fact had quite easily conceived a beautiful baby girl. This child was born perfect in every way except one- she carried a lethal genetic defect that began to show symptoms when she was about 3 months of age. They loved and cherished her until her death shortly before her 1st birthday. Genetic testing revealed an unusual defect that it was predicted would affect 1 of every 2 children born to them. Their OB had told them to go home and try again and maybe this next time the baby would be OK. After watching their first child die, they could not face a 50/50 chance of that happening again.
Pre implantation genetic diagnosis (PGD) had recently become available through most fertility centers and they came to us asking whether this would be an option for them. This technique was (and still is) somewhat controversial as many people equate this with sex selection and “designer babies.” While PGD can certainly select for sex, its main use is in helping couples who might pass on a serious or even fatal condition. Designer babies is a media fantasy, as curls, intelligence and athletic ability are not conditions available for testing.
All options were discussed with this couple- including PGD, simply trying again, early amniocentesis with early termination, donor eggs/sperm (not an option for this genetic condition) adoption and child free living. They elected to do in vitro fertilization with PGD.
The wife underwent a standard IVF cycle and 10 embryos were obtained which showed apparent normal fertilization. A single cell was removed from each of these 10 embryos and sent for genetic testing. Nine of 10 carried the lethal defect. (Genetic predictions of 50/50 were not quite accurate.) A single genetically normal female embryo was transferred and a healthy baby girl was born to them 9 months later. This was a baby they could watch grow and anticipate each tomorrow, not watch and wonder if tomorrow would be the last day. PGD did not design a Miss America or a potential Nobel Prize winner, (at least not that I know about) but it did design a family with all the potential for happiness and heartbreak that we all hope for in our families.
