ok, now you got me wondering... could a pregnant mother take this drug if they're at high risk of their fetus having CF (or confirmed via pre-testing) to prevent this?
(Or possibly will continue taking it if they have CF as we can expect more CF patients to have children)
It's a homozygous recessive disorder. If two carriers reproduce, there is a 25 percent chance the child has CF. If a woman with CF has children with a carrier, there is a 50 percent chance the child has CF and a 50 percent chance the child is a carrier.
Ninety-five percent of men with CF lack a vas deferens, leaving them effectively sterile. The medical community is understandably reluctant to assist two people with CF in reproducing together as their child is guaranteed to have CF.
If you are at risk of having a child with CF and know it, a best practice is to try to not conceive a child with CF.
I doubt taking a drug during pregnancy would prevent a male child from being born without a vas deferens and see no reason to care. Just try to not have a baby with CF. It's called a Dread Disease for a reason.
It won't alter the underlying genetic condition, but there has been at least one case report that taking these CFTR modulators during pregnancy can improve the condition of the fetus/newborn:
Both of these babies are female. I am not at all surprised that the drug helped in the way described in the articles, but it doesn't actually indicate whether or not it could impact the vas deferens since that's a defect in the male reproductive tract.
According to the CF Foundation, the cause of the lack of the vas deferens is not conclusively known.
(Or possibly will continue taking it if they have CF as we can expect more CF patients to have children)