During IVF, PGD (preimplantation genetic diagnosis) is recommended to rule out embryos with chromosomal alterations.
During pregnancy, invasive tests such as amniocentesis and chorionic biopsy allow reliable diagnoses, but always involve a small risk. Therefore, genetic testing is not mandatory in low-risk pregnant women.
The selection criteria of the pregnant woman (age, state of health, habits, previous gestation experience...) serve to rule out the greatest number of risk factors.
The gynaecologist will determine which tests are necessary in each case.