A preconceptional genetic examination usually includes:
- Clinical genetic examination – analysis of personal and family history of both partners as part of a genetic consultation.
- Chromosomal examination of both partners.
- Women in indicated cases – an examination of a predisposition to increased blood clotting, or thrombophilia (Factor V Leiden mutation and Factor II prothrombin gene mutation).
- Screening for hidden carriers of the most common hereditary diseases – among the Czech population, this is mainly cystic fibrosis (CF) and spinal muscular atrophy (SMA), but carriers of other rare diseases that may affect the senses of offspring (e.g. hearing disorders) or metabolism (congenital metabolic diseases) can also be detected.
- In men with severe sperm disorder, examination of the loss (microdeletion) of material on the Y chromosome (azoospermia factor, or AZF).
The results of the preconceptional examination provide information that enable us to suggest the best method of treatment using assisted reproductive methods, to decide on the suitability of preimplantation screening (PGD or PGS), and to create a plan for future pregnancy care (prenatal diagnosis).
Preimplantation genetic diagnosis
As part of assisted reproduction methods, embryos formed in a test tube can be subject to genetic examination and selection prior to transfer to the uterus and implantation (preimplantation).
The examination method is based on the conclusions of the genetic consultation. The preimplantation examination can be targeted either to diseases that already exist in the family or to random genetic changes brought about by the external environment or the age of the parents (preimplantation genetic diagnosis, or PGD)
- PGD (preimplantation genetic diagnosis) is a targeted examination of the embryo to exclude hereditary disease in the family, in which one or both partners are potential carriers of the disease.
- PGS (preimplantation genetic screening) is an examination of the embryos to exclude newly formed chromosome defects in a couple without genetic disorders.