Genetics and human reproduction

Most people want children, and most people want healthy children. For those couples with an infertility problem who have recourse to assisted reproduction, usually in vitro fertilization (IVF) or donor insemination (DI), the practitioners have a special responsibility to ensure as far as possible that the babies in whose conception they assist are in good health. How can they best tackle the challenge of inherited diseases, of which about 4000 are known today, and chromosomal malfunction?