Our ultrasound today showed that the cystic hygroma is still large, and not getting any smaller. (Hard to tell if it was any bigger, though...) There was definitely fluid around the lungs and some swelling, so that isn't very good news. However, the heartbeat is still strong.
The doctor is not optimistic that the baby will survive beyond 18-22 weeks, so we are still in a holding pattern; praying for a miracle, hoping for the best, but aware of the prognosis and prepared for the worst.
Because the results from the CVS test were inconclusive, we had to have an amnio performed to obtain the karyotyping that we were originally looking to obtain.
(Amniocentesis is a procedure performed during pregnancy to examine a baby's chromosomes. Most often, an amniocentesis is done between 16-20 weeks of pregnancy. During this procedure, amniotic fluid is removed, using a hypodermic needle, for testing. The amniotic fluid contains cells that the baby has naturally shed. Cells and proteins within the amniotic fluid are examined in the lab to test for specific fetal disorders.)
The amnio went well, and was much less painful than the CVS a few weeks ago. They had to draw more fluid than they would for a typical amnio because we are having more than one test performed on the samples. We are having the standard chromosome analysis done, which will tell us (hopefully) that the number of chromosomes is correct and that they are, generally, in good shape.
Because the CVS indicates mosaic trisomy 15, they will look specifically at chromosome 15 to see of there is any evidence of 3 copies of it. Normally, they would sample about 50 cells to ascertain this information. But, a mosaicism can be present in only some areas, so they will test a larger number of cells to determine with more authority if it is, indeed, present in some or all cells. (Note- the test is not exact. There is no way to test all of the cells, so they choose a number and sample what they feel will be representative of the baby.)
They will also use the amnio sample to test for an UPD, uniparental disomy. Trisomy 15 is very rare, particularly this far along in pregnancy, so there is concern that if there is any Trisomy 15 detected that it could be due to an uniparental disomy. This is when a baby inherits one chromosome 15 from one parent and two chromosome 15's from the other parent. The cells recognize that there are too many 15's, so they cancel one out in order to be left with two, the appropriate number. In some cases, that can leave the baby with two sets of chromosome 15 from the same parent, which is uniparental disomy. There is a specific name for this if chromosome 15 comes from the father or mother. They will test the baby's chromosome 15 against each of our chromosome 15's to see if what the baby has is "normal."
The other DNA test they will perform is called CGH, comparative genomic hybridization. This will analyze the baby's DNA more closely to see if anything is has been deleted or added to a specific chromosome. This is how they typically test people for being carriers of commonly known genetic illnesses, such as Sickle Cell Anemia or Tay-Sachs Disease. This will allow them to diagnose the baby with any genetic illness that is already known and identifiable. This will not, however, allow them to tell us about things that are not known yet. For example, if we are both recessive carriers of something that causes cystic hygromas, they can only detect it if that illness is linked to a specific gene/chromosome. Because the genetic counselors are unaware of any specific genetic illness that causes cystic hygromas, it is likely that we will not find anything conclusive with the CGH analysis. But, to make sure we leave no stone unturned, we have opted to pursue it.
All of these test results (amnio, UPD and CGH) should be available in about two weeks. We go back for another ultrasound on Sept. 11 to see how the baby is doing and assess the prognosis once again. We are still praying that things can turn around and the baby can recover from this. While we know it is a long shot, we are not ready to give up.
Thank you all again for the positive thoughts, prayers and support! We are so grateful to everyone for all you are doing to help us through this. We will keep you posted.
Today's appt did not go very well. The cystic hygroma has increased in size over the past 2 weeks, and is now affecting more than the back of the baby's neck. The ultrasound technician also saw some fluid around the lungs. The doctor wasn't particularly impressed by the presence of a little bit of fluid around the lungs, but he said given the growth of the cystic hygroma, he would now consider us pre-hyrdropic. Given the size of the hygroma, the doctor is not very optimistic that it can resolve on its own or that this will end well.
Because of the results of the CVS, we are scheduled to go back in a little less than two weeks for an amnio. They do not schedule level II ultrasounds on that day, but the amnio has to be done under ultrasound guidance so we will get another look at the baby that way. Regardless of the health of the baby at that time we will be pursuing further testing (amnio and a couple other tests) to try to shed some light on what may be causing the cystic hygroma. We need to determine is the baby has mosaic Trisomy 15, and if not, if there is some other chromosomal abnormality that can be found.
The genetic counselor we met with today does not seem to think the mosaic Trisomy 15 is in play here- apparently it just isn't adding up right for her, so she is skeptical. But they need to rule it out. It seems more likely that we are each recessive carriers of some genetic issue that causes cystic hygromas. Whether or not they will be able to pinpoint that issue is up in the air, and we are not entirely optimistic that they will find the ultimate issue. Unless they know what they are looking for (i.e. specific condition or issue with a specific gene/chromosome) there is no way to test for everything. If we are recessive carriers of something that causes this, we have a 25% chance of this happening in any given pregnancy.
As far as how we proceed, we are inclined to let nature take its course as long as there is no threat posed to Kara's health, which, at this point, there is not. Even though the prognosis is rather bleak, we are trying to entertain the possibility that things can still turn around. In the event that this pregnancy ends, how we deal with it, medically, will depend on how far along we are.
We will continue to keep everyone posted as we get new information. In the meantime, please continue praying that the cystic hygroma will suddenly go away and we have a shot at a healthy baby. Thanks again for all your support and positive thoughts and prayers!!
the results are inconclusive because of a mosaicism. Apparently, about 1% of the time, CVS results will return a mosaicism. This means that some of the cells in the culture have one chromosome arrangement and some of the cells have a different chromosome arrangement. In our case, specifically, 65% of the cells were normal and 35% of the cells presented with Trisomy 15 (three copies, not the normal two, of chromosome 15).
The good news is, according to the genetic counselor, about 90% of the time when there is a mosaicism the abnormal cells are from the placenta and not from the baby. The not as good news is they are more concerned than they would normally be because the cystic hygroma is present in addition to the mosaicism. However, to further confuse things, Trisomy 15 is not typically associated with the presence of a cystic hygroma.
I was a bit confused by all of this because I thought they were specifically testing a sample of the placenta, so to hear that they are distinguishing the cells from the placenta vs. the baby did not make sense. The genetic counselor explained that in fetal development, there is a specific point in time where the placental tissue and the embryonic tissue split, and each becomes an individual entity with its own cells dividing and each growing separately. Because they test the tissue from the placenta, and not from the baby, specifically, they have no way of knowing if the abnormal cells began appearing and began dividing before or after the placenta and the baby split from one another. So, in the 90% of the time where the abnormal cells are from the placenta, it is due to the cells not presenting and dividing until after the placenta and the baby are separate entities.
What does this mean?
Well...we won't know if we are carrying a baby with Trisomy 15 until we can do further testing. The genetic counselor is recommending that we do an amniocentesis, which will give us a more clear idea as to what is going on with the DNA. An amnio cannot be performed until we are 15 weeks, so we are a little early for that right now.
In the event that there is Trisomy 15, it is most likely mosaic Trisomy 15, which means it is not present in all of the cells. The extent to which that can be problematic depends on how many of the cells are affected and in which parts of the body they are located. If it was full-blown Trisomy 15, it is unlikely we would have made it to 14 weeks along because those pregnancies typically result in early miscarriage.
Regardless of whether or not Trisomy 15 (mosaic or otherwise) is determined to affect the baby, the cystic hygroma is still being treated as a separate issue, just possibly related. The genetic testing, which was supposed to help shed light on what caused the cystic hygroma, seems to have only made things more unclear...at least for the time being.
We are still scheduled for an ultrasound and to meet with the High Risk OB on Thursday. We were originally scheduled for some additional genetic testing, but that is on hold until we decide about the amnio and until we can actually have the amnio performed. (The other testing they were planning on doing was supposed to use the CVS samples, which we know will not provide results that we can rely on.) We are still hoping to hear on Thursday that the cystic hygroma has either diminished in size or gone away completely; anything but that it has grown in size or that there is evidence of fluid retention, edema or hydrops.
We will also be meeting with the genetic counselor again on Thursday to further discuss the test results we have gotten so far and other testing that should be considered moving forward.
In terms of expectations, we are still hopeful that things can turn out alright. Though, given our experience, we are also realistic about the possibilities. One of the toughest things to swallow, especially given all of the crazy testing we are doing, is that everything tested normal (DNA, autopsy, etc.) with our first pregnancy. So, while we continue to hope and pray that our test results come back normal, we know that there is no guarantee there either.
We will continue to post updates as we have additional information. Talk to you all soon!