Periconceptional clinics: a medical health care infrastructure of new genetics.

The necessary paradigm shift of medical prevention and health promotion from general prevention to specific genetic-oriented prevention require two crucial points: the selection of the optimal time for the primary prevention of birth defects and predictive genetic testing and the establishment of the appropriate healthcare infrastructure. The optimal time for the primary prevention of birth defects (e.g. neural-tube defects) and predictive genetic testing is the preconceptional period, i.e. the preparatory time for the planned conception, particularly before the first pregnancy, and the most acceptable time for the concrete diagnosis of the expected serious genetic diseases is the early postconceptional period. Theoretically, preimplantation genetic diagnosis is the optimal option for offspring of couples at high risk including autosomal and X-linked recessive, dominant disorders and chromosomal aberrations. The pre- and early postconceptional health can be addressed jointly in a new type of the health care infrastructure entitled periconceptional clinic. Periconceptional clinics seem to be appropriate for the starting point for the primary prevention of common complex diseases as well.