In a previous article, we outlined the different types of genetic and chromosomal conditions, which can potentially affect a current or future pregnancy. Contrary to what one might think, the presence of a genetic risk for one’s child is not always inevitable and reproductive planning options are offered to help in managing this risk.

Note that in most cases, you must have confirmation of the genetic risk carried by one or both future parents to be able to access these tests.

Neonatal diagnosis

This option consists of waiting until the birth of the child to carry out a diagnostic genetic test aimed at confirming or eliminating the presence of the genetic condition. Neonatal diagnosis is generally considered when the condition in question does not significantly impact the quality or life expectancy of the unborn child, when medical termination of pregnancy is not possible, or if postnatal intervention or treatment is available and could reduce or eliminate symptoms associated with the condition. Neonatal diagnosis could also be available in situations where the nature of the genetic risk has not necessarily been identified, for example following the finding of suspicious ultrasound signs in the prenatal period.

Prenatal diagnosis

Prenatal diagnostic procedures are invasive techniques, meaning they are associated with a risk of pregnancy loss. This option consists of a DNA sample taken directly from the pregnancy by chorionic villus sampling or by amniocentesis, and makes it possible to obtain definitive information on the diagnosis of the genetic condition in question. This approach is generally considered when the decision whether or not to continue the pregnancy would be impacted by confirmation of the diagnosis, or if prenatal treatment is available to improve management of the pregnancy and/or symptoms associated with the condition. Some parents could decide to accessthis testing to prepare for the arrival of a child who may need special care. Prenatal diagnosis could also be available in situations where the nature of the genetic risk has not necessarily been identified, for example following the finding of suspicious ultrasound signs in the prenatal period.

Pre-implantation genetic testing (PGT)

Embryos resulting from in-vitro fertilization (IVF) can be tested before they are transferred in order to assess the presence or absence of the genetic or chromosomal variant, only if this has previously been identified in one or both future parents. This procedure can be chosen even in the absence of a fertility problem in the couple, when the option of medical termination of pregnancy is not possible or a couple wants to avoid this as much as possible, and if the presence of the condition could impact the decision to have a child. Note that unlike prenatal diagnosis which is only permitted in the case of severe conditions with early onset, PGT is sometimes used to choose embryos to transfer that are not carriers of reduced penetrance conditions (i.e. only a portion of people carrying the genetic variant in question will present symptoms) or with onset in adulthood. This will involve selecting only the embryo(s) identified as not having the condition for transfer into the uterus. Prenatal diagnosis is generally recommended in pregnancy in order to confirm the result, sinec PGT is not 100% diagnostic.

Other options…

When none of the options mentioned above are suitable, fertility issues are involved, and/or the couple wishes to eliminate the risk of transmission of a genetic condition for which one or both carries a risk, it is possible to consider other options like gamete (egg or sperm) donation, embryo donation, or adoption.

How to choose?

This is a very delicate choice that could have a significant impact on your family. The decision to proceed with one  of these options should be accompanied by genetic counselling in a personalized process to support informed consent. If you are faced with a decision in this context, do not hesitate to join our expert team of genetic counsellors who can provide you with the support you need.