It is estimated that about 20% of reproductive problems are genetic or chromosomal type. That is why today genetic testing is an essential part of the fertility study in couples who come to our clinic looking for descendants.
For the diagnosis of fertility problems there is a set of genetic studies very useful in the assistance of couples with reproductive desire. Tests such as the karyotype in both partners, microdeletion of the Y chromosome in the male or the molecular study of fragile X syndrome in women are usually required tests to determine a possible genetic basis of fertility problems in couples.
But, there may be a genetic incompatibility between a man and a woman that prevents them from having children but not with another couple? The answer is no.
Recessive hereditary diseases are the exception. These diseases need to demonstrate that both the gene copy inherited from our father and our mother are both mutated. If only one copy is mutated and the other not, the person is a carrier and has none of the clinical symptoms of the disease. If by chance both partners are carriers of the same recessive genetic disease they could pass it on to their offspring with a probability of 25 percent. Depending on the severity of the disease it may even result in pregnancies not coming to term.
Therefore, a family history of miscarriages, newborn malformations or mental impairment may be due to genetic or chromosomal alterations which must be identified. In these cases adequate preconception advice is necessary because today genetics allow us to offer solutions as Preimplantational Genetic Diagnosis (PGD).