For spontaneous pregnancies, non-invasive prenatal screening (NIPT) and invasive prenatal diagnostic tests (IPNDT) are options. In the context of in vitro fertilization treatment, pre-implantation screening (PGT-A) is possible. It allows the implantation of euploid embryos and thus avoids the effect of maternal age.

Individual risks: a preimplantation diagnosis solution also exists for carriers of balanced translocations, PGT-SR, allowing the transfer of embryos that have a balanced or normal set of chromosomes. If the unbalanced fragments are sufficiently large (>10 Mb), then NIPT is possible and IPD is practicable.

Tests to detect mutations responsible for hereditary diseases are available to couples exposed to risks due to family history or origin, or at the choice of the couple (carrier screening). This approach comes in several options involving an increasing number of analysed genes:

(i) a minimum number of six genes responsible for the most common hereditary diseases (cystic fibrosis, spinal muscular atrophy, fragile X syndrome, alpha and beta thalassaemia, and sickle-cell anaemia, according to the American College of Medical Genetics (ACMG);
(ii) the genes conferring an increased risk of recessive diseases in persons of Ashkenazi Jewish origin (the ACMG recommends the screening of four genes); and
(iii) the screening of a wide range of genes, known as expanded carrier screening. This final option should be carefully discussed in terms of improved diagnostic yield and excess information (Mol Genet Genomic Med 2020: 8:e 1053).

If one or both partners carry mutations that result in an increased risk for the offspring, several reproductive options are available

pre-implantation diagnosis (the PGT-M),
invasive diagnostic testing (IPNDT).

Genesupport - All the risks before pregnancy