Having children while being a person with CF

Question

If one is affected with CF can one have normal children ?

Answer

Hello,

Your question « Is it possible to have normal children while being affected by cystic fibrosis ?» is very brief and not quite explicit ; so I hope to answer it correctly, otherwise you will have to develop a little further what you wanted to know exactly.

First of all I would like to remind you that before conception, the partner of the person with cystic fibrosis would have to undergo a genetic test to determine if he/she is a ‘carrier’. Depending on the countries, we test 30-35 mutations that are the most frequent in our regions (!). If the partner isn't a ‘carrier’ according to the results of the genetic test, the risk that the child will be born with cystic fibrosis isn't zero, but minimal. If the partner is a ‘carrier’, the risk to have a child affected by cystic fibrosis is 1 child out of 2 (50 %). In this case, they are different options: some couples decide to follow through with the conception (depending on their beliefs and/or the type of mutation concerned), for other couples the doctors can select the embryo(s) who are just ‘carrier(s)’ of the mutation of the partner affected by cystic fibrosis (who inevitably will give one mutation to his/her child, see below), other couples will reconsider their plans to have biological children together.

I assume that you know that women affected by cystic fibrosis can conceive children and carry forward the pregnancy provided that their respiratory function and general state is preserved. Men, it depends a bit on their mutations, are often technically sterile, which means that because of the bilateral absence of vas deferens (a spermatic duct or chanal), the spermatozoa are present in the testicles, but cannot be ejaculated and, thus, are not present in the semen fluid. A sample of the spermatozoa can, however, be obtained by puncture of the testicles or surgically, this is done under local or general anesthesia. As the spermatozoa are a little immature and cannot move normally, an in vitro fecondation is often done with the ovocyte of the female partner and, then, the embryo is implanted into the mother's uterus.

I will now come back to your question «are the children ‘normal’ ?» (even if I don't really know what you mean by ‘normal’). The child, who has a parent affected by cystic fibrosis, will inevitably inherit one of the mutations responsible of cystic fibrosis. So, he/she will be what we call an obligate (healthy) ‘carrier’ and be in the same situation as the parents of the affected partner.

As you know, in our population, one person out of 25 to 30 is a ‘carrier’ of one mutation of the CFTR gene.

There is no large scale study that has examined if being a ‘carrier’ has a positive or negative impact on a person's health.

On the other hand, there are some studies in the medical literature, which have studied persons affected by certain illnesses and that have tried to find out if there are more carriers in some disease conditions, which could mean that the ‘carriers’ could be predisposed to certain diseases. This kind of study has been done for respiratory diseases. In a large group of children with asthma, carriership was not more frequent. On the contrary, in cohorts of persons with allergic asthma caused by a mould called Aspergillus, chronic rhinosinusitis, nasal polyposis, chronic pancreatitis (not caused by the abuse of alcohol) and infertility an increased number of ‘carriers’ can be found. This could indicate that ‘carriers’ are more subject to these kinds of medical problems/diseases, but this could also mean that in a certain number of cases a cystic fibrosis diagnostic was impossible to establish in some of these persons with the current methods.

Carriership could also protect from certain medical problems/diseases. Why are there so many ‘carriers’ in our population? The hypothesis is - amongst others- that the carriership would protect against infectious gastro-intestinal diseases that killed a lot of people in our regions before our modern times. Even recently, some studies have tried to determine if carriership protects against diseases like arterial hypertension, gastro-intestinal diseases, cancer. No definite results are available yet.

You see that – with the information currently available - I cannot answer with certainty to the question “Does being a ‘carrier’ of one mutation of the CFTR gene generates health issues and/or protects against particular medical problems?”. As there are different categories of mutations, this will probably also depend on the type of mutation considered. The future will tell us.

Finally, in order to be complete, I would like to tell you that besides the fact of being an ’obligate carrier’, a child from a mother with cystic fibrosis can be put at risk if the mother isn't in a good shape or doesn't stay in good shape during the pregnancy. Indeed, the mother's recurring respiratory/infectious problems can lead to the fact that the child is small for gestational age. If there is diabetes before or during the pregnancy, it should be managed for the best. Otherwise, all these factors may increase the risk of a premature delivery and prematurity is a risk for any baby's health. Therefore it's very important for women with cystic fibrosis to really plan their pregnancy, to be correctly prepared and to be regularly medically examined so that everything works for the best.

To finish on a positive note I would like to tell you that - in my experience - nowadays more and more adults with cystic fibrosis have children and really beautiful children too!

Best regards,

Christiane Knoop

15.11.2011