Possible Pregnancy, CF and IVF

Question

We have tried IVF and we are at a very early stage. Unfortunately I did not manage to do any testing for CF. I am now gathering information about it. I would like to know (if we get positive results about the pregnancy) when and how I can find out if the embryo is a carrier and if there is any treatment.

Answer

Dear questioner,

In general, in some European countries parents, especially if they are undergoing IVF, can be screened if they are carriers of a CF-mutation even if there is no family history of CF. So are you positively certain that you were not tested for CF mutations during the testing you received before you proceeded to the IVF procedure?

In other countries this is not the case and screening is only performed if there is a family history of CF. Screening of the unborn child just for instance without a positive family history of one of the parents or without the known fact that both parents are carriers of one CF mutation each, is generally not recommended.

So in your case, if there is a positive family history of CF, it is very important to test both of the parents and only in case both turn out to be carriers of one CF-mutation each it would be advisable to test the fetus by doing an chorionic villus sampling (from the 11th week of pregnancy on) or an amniocentesis (from the 16.th week of pregnancy on). If both parental mutations are known, the test of the fetus if it has inherited none, one or both mutations is very reliable. If testing of both parents is not possible anymore for some reasons (e.g. time frame), the fetus can be tested for CF mutations by the mentioned investigations, however it remains a small risk that the fetus carries a mutation that cannot be detected by the test.

In case, there is no CF family history at all and you just “missed” the standard routine screening for CF performed probably to all parents undergoing IVF in your region and the reason for infertility was not a so-called CBAVD (congenital absence of vas deference in the male partner) , then the risk of getting a child with CF for you as a couple is not increased compared to the risk of the general population; in this case, one would in general not recommend a “for instance screening” of the fetus, but the decision has to be taken by you as parents together with your physicians in charge taking into account many multiple factors: e.g. risk of the investigation vs. risk of the special illness, offering of the investigation by national programmes vs. parents have to pay it themselves etc.

I think that you must immediately discuss the issue with your obstetrician and the IVF center you are visiting.

Yours friendly,

Dr. Stavros Doudounakis and Dr. Daniela d’Alquen

14.02.2012