We got the call this afternoon with the FISH results. And, so far, everything is testing normal:-) This means that the baby does not have Trisomy 13, 18 or 21 (Down Syndrome). This also means that the baby has the right number of chromosomes: 46. This does not guarantee that there isn't a chromosomal or genetic abnormality, it simpy rules out some of the most predominant ones, and a couple that are most frequently associated with cystic hygroma.
So, no we wait until we get the full DNA analysis back, and we wait for our next ultrasound. I am sure the next 2 weeks will be wrought with anxiety as we wait, but we are grateful that the first set of results came back in our favor. Keep saying tholse prayers!! And thank you for all of the support so far- we are lucky to have the support of so many family and friends.
I also thought it would be helpful to share some of the main points that we discussed with the doctor when we had an opportunity to ask some questions:
- In his experience, the doctor feels that the majority of cystic hygromas resolve on their own. He
said he understands it would easy to let ourselves be discouraged and go down the path of what
happened last time, but he doesn’t want us to jump to any premature conclusions because it is
still early
- Doctor explained that cystic hygromas normally develop in one of 2 situations:
- Thoracic duct does not develop to manage fluid between the lymphatic system and venous
system so fluid builds up at back of neck. There is still a possibility that the duct will develop
and the cystic hygroma will resolve
- The heart forms abnormally and throws off the pressure and flow of fluids in the body and
fluid collects at back of neck
- There is nothing that we did to cause this, and there is nothing we can do to try to prevent it from
growing, getting worse- drugs, dietary changes, etc.
- There really isn’t any treatment available in-utero; any possibilities are invasive and pose more
of a threat to the baby than doing nothing
- Currently the heartbeat is normal and there is no sign of hydrops. The doctor would expect that
to develop by 18-20 weeks and will indicate heart failure is imminent. Until then, we will monitor
via ultrasound.
- If the cystic hygroma looks to be resolving on its own, we will still need close monitoring and a
fetal echocardiogram around 20 weeks to confirm that there are no major heart defects. If that
looks good, he would likely consider us “normal” again, but would still recommend being more
closely monitored by ultrasound to be safe.
- Doctor does not think that this is linked at all to my recent diagnosis of a single MTHFR mutation
(the blood clotting thing that prevents the absorption of folate and B vitamins)
- He also does not think it is related to our Unexplained Secondary Infertility
- The only risks that the pregnancy pose to Kara at this time are pretty rare
and unlikely:
- Mirror syndrome- if the baby gets hydrops, in very rare cases the mother will mirror those
symptoms
- Risks associated with C-section if baby gets hydrops that are very extreme and has to be
delivered by C-section
We met with the High Risk Team today in Evanston. The appointment lasted about three and half hours. First, we had a level II ultrasound to confirm the presence of a cystic hygroma. The ultrasound technician did so, and it measures from 7-9 mm. (A "normal" fetus will have some fluid at the back of the neck, but that measurement should be no more than 3.5 mm.)
After that, we met with a Genetic Counselor. She reviewed the paperwork from our first pregnancy (chromosome analysis, autopsy report, etc.), our medical histories, family medical histories, etc. Nothing seemed to indicate to her that there was any specific reason why we now have 2 pregnancies in a row with cystic hygromas.
We then met with the doctor, who performed the CVS test almost immediately. Due to the location of the placenta, he had to pass a needle through my abdomen to gather the placental tissue that needs to be evaluated. The test was pretty unpleasant (and Matt was a funny shade of green:-)), but it was over quickly and they showed us the baby's heartbeat as soon as it was over to assure us that everything was ok.
We should have the initial FISH results back on Monday, which will tell us the sex of the baby and if the baby has Trisomy 13, 18, 21, or any abnormality associated with the sex chromosomes (ie- a female with only one X chromosome). The full DNA analysis/karyotyping will take about 2 weeks.
We have an appointment in 2 weeks on August 13 to see if the cystic hygroma has grown, decreased in size, stayed the same, etc. and to confirm that the baby is still in decent health otherwise. At this time, there is no evidence of fluid in other areas of the body, and hydrops is not present. We are hoping that that continues to be the case.
CVS (Chorionic Villus Sampling) is a technique that is offered for prenatal diagnosis of chromosomal abnormalities associated with advanced maternal age or fetuses that have abnormalities, and can also diagnose certain other genetic diseases. CVS cannot be used to assess the risk for neural tube defects. CVS is performed between 10-13 weeks of pregnancy. During the procedure, a small sample of the placenta, called the chorion, is removed under ultrasound guidance. The main advantage of CVS over amniocentesis (amnio- an alternative to CVS) is that prenatal diagnosis is achieved during the first trimester.
Prior to the procedure, we will have the opportunity to meet with a genetic counselor to review family history, discuss the procedure and ask questions. After genetic counseling, an ultrasound will be performed to determine the location of the fetus, confirm gestational age and locate the placenta. If the placenta is posterior (at the bottom portion of the uterus), a catheter is passed through the cervical opening under ultrasound guidance. The tip of the catheter is directed toward the placenta and a small sample is removed. If the placenta is anterior or fundal (at the top of the uterus), a needle will be passed through the maternal abdomen and uterus into the placental substance, also under ultrasound guidance. Samples are forwarded to the cytogenetics laboratory for processing and diagnosis.
Full results of the CVS are typically available 1-2 weeks after the CVS is performed. However, a FISH (flourescence in-situ hybridization) test will screen for gender and Trisomies 13, 18 and 21, and those results are typically available in 24-72 hours.
A cystic hygroma is a fluid-filled sac that results from a blockage in the lymphatic system. The lymphatic system is a network of vessels that maintains fluids in the blood, as well as transports fats and immune system cells. Cystic hygromas are thought to arise from failure of the lymphatic system to communicate with the venous system in the neck. Cystic hygromas are single or multiple cysts found mostly in the neck region. A cystic hygroma in a developing baby can progress to hydrops (an excess amount of fluid in the body) and eventually fetal death.
Cystic hygromas occur in approximately 1% of fetuses between weeks 9 and 16 of pregnancy.
The majority of prenatally diagnosed cystic hygromas are associated with one of the following: Turner Syndrome (Monosomy X- an abnormality where a female has only one X chromosome, not two), Trisomy 13, Trisomy 18 (Edward's Syndrome), Trisomy 21 (Down Syndrome) and Noonan Syndrome. For a baby with no known genetic or chromosomal abnormality, a cystic hygroma may be caused by a birth defect (heart defect, digestive system defect, musculo-skeletal defect, etc.). In some situations, a cystic hygroma can be present in a healthy baby.
Overall, there is generally a poor prognosis associated with fetal cystic hygromas. In cases where genetic or chromosomal abnormalities were not present, there is research to indicate that a cystic hygroma may resolve on its own. In cases where a cystic hygroma did not resolve on its own by 20 weeks gestation, the outcome was generally poor. Hydrops (retaining of fluids in the body) results from vascular damage and high output heart failure. Hydrops occurs up to 75% of the time with a cystic hygroma and is almost always associated with miscarriage or fetal death.
Recurrence of fetal cystic hygroma in subsequent pregnancies is extremely rare. I have only found around 20 documented cases that have been published in medical research. While it is possible that it can happen by chance and be caused by completely unrelated events, it is unlikely. There is literature to suggest that recurrence can be the result of a familial inheritance pattern, most likely an autosomal recessive gene.