Genetic tests are an important part of every pregnancy. The tests are meant to check the genetic compatibility between the sperm and the egg, and to prevent a situation where the children are born with a disease.
Where I live (Israel), for example, heterosexual couples who want to test whether they are genetically compatible before they try to get pregnant, can do several basic tests that the state will cover for about 10 diseases and mutations, and if you have private insurance you can do more extensive genetic panel tests.
All the more so with surrogacy, when the goal is to maximize the chances of a successful embryo transfer and a normal birth, the highly recommended approach is to do as many tests as possible.
When I went through the process in 2014 the common extended panel was for 100 diseases, while today the common ones can be up to 280 and there are of course much more extensive panels. In the end you have to remember that there are a lot of disease and genetic mutations that you can look for, and you can never test for them all.
It’s important to speak with a genetic counselor and customize the necessary tests you should do. The counselor will speak with you and build a “family tree” where they will analyze situations, existing diseases and impairments that may be genetic - and suggest specific extensions to the basic test panel.
In general, these panels test to see whether you are a recessive carrier. It doesn’t mean you’re sick, or that you may get sick, just that you’re a carrier. Every carrier has its likelihood of becoming a disease and its chances of being passed on to your offspring.
What’s important to verify is that you and the egg donor aren’t carriers for the same disease and mutations. That’s why it’s very important to be tested for the same panel. If one side is positive for a specific mutation, it’s imperative to verify that the other person is tested for the same gene and to rule out that they are a carrier.
There are also advanced tests on the embryos (PGT-M) if you are a verified carrier for a genetic disorder (such as BRCA that causes breast cancer - you’ll want to check at least all the female embryos). It involves a biopsy that is taken from the embryo and it’s compared to a sequence that will be taken from you or the carrier family members. The PGT-M test is a complex issue on its own, and I’ll elaborate on it in another post.
