If You are a Carrier Pregnant with a CF Child
Unless there has been a history of CF in the families of both parents, the arrival of the first CF baby usually comes as something of a shock. Nevertheless, a small number of families elect to have additional children despite the 1 in 4 risk that any new child will also have CF. (Unfortunately, the overwhelming majority of CF fetuses identified in the womb are now aborted.) Mothers pregnant with a fetus that might have CF do have the option of prenatal genetic testing that will look for the presence of two CF mutations in the fetus' genetic code. Other mothers elect not to do such prenatal testing. Either way, a woman pregnant with a fetus they either know or suspect has CF will wonder if there is anything they can do to lessen the chance that the baby will suffer complications in utero.
Until very recently, the answer was no. All that could be suggested was ultrasounds in the third trimester to look for signs of incipient meconium ileus (severe bowel blockage) that might necessitate emergency Caesarean delivery and immediate surgery for the newborn. However, some very recent research argues that supplementation with CF modulators such as Trikafta may be important to protect the health of a CF fetus. In the 30 July 2020 issue of Nature (Vol. 583; S6-S7), Elie Dogan writing "The Sooner the Better: To Safeguard Organs, Therapies Must Tackle Cystic Fibrosis in the Womb," notes there is a new blood test for pregnant women that can diagnose CF down to the mutation level in utero at 10 weeks (It's called the UNITY test from BilliontoOne in Menlo Park). Researchers are using therapies prenatally to see if they can prevent organ damage. They have done experiments in CF mice where they injected gene therapy with working CFTR into the amniotic sac, and the mice did not develop the characteristic bowel obstruction they otherwise would have. What's surprising is that there was no working CFTR when the mice were born, but just a few days of working CFTR prenatally prevented the damage. Another team used CRISPR gene editors in amniotic fluid in late pregnancy to reverse a surfactant deficiency. This same team claims (but has not published the research) to have been able to do the same with the CFTR gene in mice. There is also the potential for the mother to take CFTR modulators during pregnancy to prevent organ damage in the fetus. In a CF ferret experiment, ferret mothers taking ivacaftor helped the young ferrets avoid organ damage.
In addition, two nutritional supplements - DHA and GSH - may lessen or even prevent the manifestations of the disease that begin even in utero.
DHA is docosahexaenoic acid. Recent research has shown that CF persons suffer from a 3-fold decrease in the amount of this lipid present in the cell membrane. (Please see section on DHA for more information and scientific references.) The researchers argue that this lipid imbalance plays a role in the development of inspissated plugs in the pancreas and other organs - which plugging begins in utero. The researchers suggest that supplementation of the mother with DHA will tend to rectify the lipid imbalance in her fetus, thus preventing the development of such plugs even in utero. Their theory suggests that the chance of the fetus developing potentially life-threatening meconium ileus can be drastically reduced if the mother's diet is supplemented with DHA. (It is important that the supplement taken contain only DHA, and not any other fatty acids such as EPA or linoleic acid, which compete with DHA for placement in the cell membrane.)
GSH is reduced glutathione. GSH is the most important antioxidant in the body for neturalizing water-soluble oxidants. It is also a powerful mucolytic. For our purposes here, it is glutathione's third property as an important regulator of inflammation that we will discuss in this context. Researchers have shown that the chronic and excessive inflammation that characterizes CF begins in utero. This inflammatory state directly damages the tissues of the body, which in turn primes the body for bacterial colonization as well as eventual immunodeficiency. If one could lessen or even shut off the very start of that inflammation which begins in utero, the CF infant should have a better start in life. In 1998, researchers first noticed that the CFTR channel, which channel is missing or defective in CF persons, is the main efflux route of cellularly-produced GSH (see section on Glutathione for more information and scientific references). This is a very important finding, as the redox state of GSH in immune system cells is the primary trigger of inflammation in the body. If GSH becomes depleted in immune system cells, inflammation begins. This is precisely what begins to happen in the CF body, and this is what is hypothesized to be happening in utero. This theory suggests that supplementation of the mother with GSH may tend to lessen any GSH deficit that may start to develop in the immune system cells of her fetus. This should serve to lessen or even shut off the origin of fetal inflammation.
Thus, in addition to all of the usual vitamins and minerals a pregnant woman is asked to take, a woman who is pregnant with a fetus that she knows or suspects to have CF might also consider supplementation with both DHA and GSH. DHA and GSH are both nutritional supplements available in health food stores without any prescription. And, given that the woman herself is a CF carrier, and therefore suffering to a lesser degree from the CF mutation, the additional DHA and GSH might do her own body good as well! (Please also see our link on the importance of a postpartum Vitamin K shot for a CF newborn.)
One last piece of research will also be useful to the woman: pregnant CF carriers tend to develop gestational diabetes during pregnancy. Alert your obstetrician or midwife to that fact, so that precautions can be taken. You may need to avoid certain types of food, such as sucrose, during your pregnancy. You may also gain more weight than the average pregnant woman because of the gestational diabetes. One good thing is that unlike non-CF carriers that develop gestational diabetes, you are unlikely to develop potentially dangerous hypertension. The reason for this is that CF carriers, like CF persons, tend to have lower-than-average blood pressure to begin with. This is one of the few blessings of having a CF mutation! However, you cannot count on this as a certainty. We have heard from one mother, a carrier of the delF508 mutation, who did have high blood pressure while pregnant. Another observation has been that the placentas created by the bodies of CF carriers tend to become quite calcified - almost to the same extent as if the mother was a heavy smoker. It is theorized that this has to do with the impaired absorption of minerals by the CF carrier's body. This may also be important for your doctor or midwife to understand.