Friday, November 7, 2008

Choroid Plexus Cysts

Although I may occasionally try to follow current events with the blog, I purposefully tried to stay out of the election fracas. I figure you got bombarded with enough info from other sources that you don’t need my opinion too, even though my opinion would have been the cherry on top. Besides, I would have gone through the trouble of doing weeks of footwork on each candidate to write a brilliant article about who is best for the country and the world in general, and then people would just vote for the guy making fart noises with his armpit because they think he’s funny. Well, it’s all over anyway, and the good guys won. I’m glad because I would have lost all faith in America, sunk into a cynical, misanthropic hole and emigrated to Canada if the other team had come out on top. Now we wait to see if anything will change for the better. So, anyway, that frees us up for a little marginally informative arcane bullshyte from Daniel P.

This week I wanted to touch on a subject that the wife and I had to deal with during the last pregnancy, and thousands of expecting parents deal with every year. At around mid-term there is a recommended ultrasound to check to see how the developing fetus is progressing. They check a whole bunch of things including head circumference, spine formation, hands feet, eyes, heartbeat, etc. They check the brain to see how that is developing as well, and this is where our topic for this week arises. During this routine ultrasound the radiologist noticed several dark spots in the fetus’ brain. I noticed them as well, and I immediately thought, “Brain cloud?” But the woman assured me that is was not, in fact, a brain cloud. However, the look on her face was disheartening to say the least. On a side note, if you haven’t been through the whole ultrasound thing, it’s a little creepy. You’re in a quiet, little dark room staring at a fuzzy black and white monitor trying to guess what the hell you’re looking at. The first time we had one for Jax I half-expected something to flash across the screen and start to tear its way through the wife’s guts. Too many horror movies, I guess. Anyway, I’m just saying it’s weird. So, back to the original story. We could tell she thought that there was something wrong, which made the wait for the doctor a real joy. When the doctor came in she explained in a somber voice that they had indeed found something on the ultrasound that was abnormal. I wasn’t too surprised. Since I don’t figure I’m terribly normal, my DNA shouldn’t be far off. Anyway, she told us that the spots on the brain were called choroid plexus cysts, and they could be an indicator that the pregnancy wasn’t going to last. Nice. One of the worst possible outcomes for the day, don’t you think?

The choroid plexus is an area of the brain that isn’t involved thought, personality, sensation, or motor control. Rather, the choroid plexus serves to make the fluid that protects and nourishes the brain and spinal cord. When a fluid-filled space is seen in the choroid plexus during an ultrasound, it is called a choroid plexus cyst (CPC). The CPCs can vary in size, shape and number and can be found either on one side of the brain (unilateral) or both sides (bilateral). CPCs are believed to be caused by abnormal folding of the epithelial lining of the choroid plexus which traps fluid and debris.


CPCs are not harmful to the fetus, but they are an indicator that something else may be wrong. That “something else” is usually trisomy 18, and it is nothing minor. Typical characteristics of trisomy 18 include: heart defects [VSD (Ventricular Septal Defect): a hole between the lower chambers, ASD (Atrial Septal Defect): a hole between the upper chambers, and coarctation of the aorta: a narrowing of the exit vessel from the heart], kidney problems, part of the intestinal tract is outside the stomach (omphalocele), the esophagus doesn’t connect to the stomach (esophageal artesia), excess amniotic fluid (polyhydramnios), clenched hands, rocker bottom feet, delayed growth, small jaw (mycrognathia), small head (microcephaly), low-set ears, strawberry-shaped head, severe developmental delays, and umbilical or inguinal hernia. More than 90% of fetuses with trisomy 18 have a heart defect. The condition is not compatible with life, and only 5% to 10 % of infants that are carried to term survive the first year after delivery. This is not something that you want to hear from the doctor.


After dropping the bomb she started to throw out some statistics. About 1% of the fetuses that have CPCs will have trisomy 18. There are certain factors that increase risk such as: the age of the mother and weather there have been other instances of this in earlier pregnancies. There are some non-invasive tests that the radiologist did to determine if there are other markers for the defect, such as: a malformed heart, head, hands or feet, and stunted growth of the baby. When no other abnormalities are found, the diagnosis is called an "isolated CPC." However, we were informed that amniocentesis is the only way to know for sure before birth that the baby does not have a genetic disease. Even though amnio can give definitive answers it carries its own risk. The doc said that 1% of women who get an amniocentesis test will spontaneously lose the baby.
At that point we were sent home to sort things out.

This, of course, is a hugely stressful time in any parent’s life, and the news that there may be dire complications with any pregnancy makes things exponentially worse. I immediately started to do a web troll to find information about CPCs and trisomy 18. The initial surface information seemed to support the doc’s stats, so we based our decision on those. So, basically our choices as presented to us were to do nothing or get an amnio test (which we considered to be foolish since we were told the risk of termination was the same as doing nothing). Since we didn’t fit the mold for other risk factors and all of the other fetal telemetry was normal, we decided to wait it out. Everything turned out for the best, but the stress that was dumped on us was something I could have done without. So now that I am removed from the situation I’d like to see if it was necessary at all.


After quite a bit of digging around, here is what I found. A meta-analysis of 33 different studies shows that over 50% of fetuses with trisomy 18 have CPCs. The opposite is not true. Most fetuses that have CPCs do not have trisomy. It turns out that the number that the doctor gave us about the percentage of fetuses with CPCs that will have the defect was correct. One percent will have the defect. This leaves us with another crucial piece of information that we need to be truly informed. What percentage of fetuses will show CPCs as a normal part of development? This number was a little harder to come by since some of the studies that I looked at involved high-risk pregnancies. However, a good average would be that about 1 out of every 122 fetuses will show CPCs (0.8%). That leaves us with this conclusion: 1% of 0.8% of all pregnancies will have the defect or 0.008%. You are twice as likely to die in a house fire. If you are not high-risk, and there are no other markers on the ultrasound then the odds are infinitesimal that the fetus will have trisomy 18.

Also, as the result of a very large study that included documentation of outcomes following mid-trimester amniocentesis, I tracked down some more-realistic numbers for the possible outcomes there. In this study, the spontaneous fetal loss rate at less than 24 weeks following amniocentesis was 1% compared to the background loss rate in the control group of 0.94%. Therefore, the added risk of the amniocentesis was calculated to be only 0.06% (1% minus 0.94%) making the risk of the amniocentesis approximately 1 in 1600 – way less than the 1% that we were quoted.

With these numbers being so low, why were we led to believe that the house of cards was falling down around us? I can only assume it is to avoid some sort of malpractice lawsuit. Also, fear sells. By keeping us in fear they can extract some more money from us in the form of extra testing. I don’t really understand, because we could have been given the information in a more positive light. Something like: “Hey, folks. Well, we found a little blip on that freaky ultrasound of yours. It’s nothing to worry about, since we did several other checks that didn’t show abnormalities. Kind of like a hangnail or an extra finger…” Guess that’s one reason I’m not an OBGYN…one of many, many reasons {shudder}.

So what’s the take-home message here? Regardless of their number, shape or size, choroid plexus cysts are not harmful to the fetus, and they nearly always go away by the third trimester of pregnancy. Any expecting parent that gets the unexpected diagnosis that the bun they are cooking has CPCs shouldn’t be too terribly concerned since over 99% of the time this is just a normal developmental process. As long as you don’t fit the bill for high-risk pregnancies and none of the other markers are found, you should probably consider it business as usual. The stress that an expecting mother feels in this type of situation is more dangerous to the developing fetus than the finding of CPCs. Just be sure to let your doctor know that you’ve decided to follow the sagely advise of an evil misanthropic genius without an MD, but I did stay at a Holiday Inn Express last night...

7 comments:

Anonymous said...

YOU KNOW SOMETIMES DOCTORS THINK THEY KNOW EVERTHING BUT AS IT TURNS OUT, THEY DO MAKE METAKES.FOR ONE THING HOW THE HELL DID I END UP WITH TWINS, AND WHEN I WAS SIX MONTHS ALONG THEY TELL ME THERE IS NO HEART BEAT AND COME BACK IN A WEEK, HOW MESSED UP IS THAT?YOU KNOW A DR. TELLING YOU ALL ALONG YOU ARE ONLY HAVING ONE KID AND OUT POPS TWO, THANKS DOC FOR NOT KNOWING YOUR JOB. YOU TWO ARE SO LUCKY WITH THE GREAT KIDS YOU HAVE, I PRAYED THAT EVERYTHING WAS ALRIGHT. NOW YOU CAN ENJOY THEM .WE ALL HAVE TRAILS WITH ARE KIDS I CANT WAIT UNTIL THEY ARE GROWN.... OH WELL YOU ARE DOING A GREAT JOB.........

Anonymous said...

My daughter is pregnant and she is about 28 weeks. Her baby has been diagnoised with Turner Syndrome. The fetus weighs about one pound 6 ounces, she has a heart defect, and one working kidney. Can anyone tell me what the chances are survival. The fetus also has a cyst of some kind on the neck, which has to be removed after birth. The mother made a decision not to abort the prenancy, but the baby is now suffering because of it, and she is still in the womb. Any comments from anyone who knows anything about her condition?

Dan said...

Sorry to hear about your daughter's prenatal issues. Turner syndrome is a sex chromosomal abnormality typically involving the presence of one X chromosome and the complete absence of a second sex chromosome. Unfortunately, the likelihood of the fetus going to term is not very good. However, in the absence of serious problems such as cardiovascular and renal defects or hypertension, or if the problems are successfully treated, the life span of an individual with Turner syndrome is expected to be normal. Check this site for lots of great info on Turner's: http://www.dshs.state.tx.us/birthdefects/risk/risk25-turner.shtm, and talk to your doctor. Hopefully someone else will chime in here.

Keep your chin up, all things must pass.

Anonymous said...

I just wanted to say, my son has choroid plexus cysts. I had 2 ultrasounds during my pregnancy. Nothing ever came back abornal, everything was good. After he was born, when he was 2 months old, he had an MRI done because his brother accidentally hit him on the head so they did one to make sure he was alright. He was fine, except they found an 'abnormal abnormality.' So when he was 6 months old they did another brain MRI. Turns out he had 2 cysts, bilateral. They diagnosed it as Choroid Plexus Cysts. I dont mean this to scare anyone, just an FYI that my son unfortunately is one of the few that it happened to not during gestation. He is doing very well though, very healthy baby. He is crawling now, and has the most precious smile and laugh ever :) He will turn 8 months old in one week.

Anonymous said...

I am 27 weeks now and our baby has been diagnosed with CPC. My doctor is an old timer with a bed side manner that leaves something to be desired. He gave me absoloutely no information on these cysts and I left his office feeling as if the world was crashing down. I did my own research and found that these cysts are actually quite normal and present little threat to the fetus itself. We were scheduled for another ultrasound and the cysts were still present. I am now seeing a specialist and waiting to see what test he will want us to do. I know either way that this gift inside me will be ours and loved just like our first two.

Anonymous said...

I found this website very informative. I felt a lot better after reading it, since it is a really uncomforting feeling that something could be wrong with your baby. I found out today that I need to go for more tests (ultrasounds) to see whether or not there could be something wrong (choided plexus cyst) with my baby girl. After 5 months of carrying her, i would be devestated to lose such a precious gift! thank you for your consideration and care

Anonymous said...

I was just told today at 22 weeks that our baby also has CPC's (3 to be exact). Dr also said "not to worry" as there were no other abnormalities noted in the ultrasound but that's easier said than done. Your article definitely helps though. We have a follow-up ultrasound at 28 weeks due to a cord issue (not centered on the placenta) and although they haven't mentioned checking the CPC's at that scan, we are going to ask that they do. I'm praying they will be long gone and all of this stress will be nothing but a memory.