Well, what can I say. Babyhood is filled with the unexpected, and sometimes it comes as a surprise.
After our ultrasound, THE ultrasound (see earlier posts), the doctors took a good look at the images. They saw something that warrented a phone call. What they told Mandy on the phone sounded pretty scary at first, but now that we understand it, I think we'll be just fine.
What they found was a small cyst in the baby's brain area, specifically a "Choroid Plexus Cyst". It occurs in one area of the brain where there is some fluid, and is apparently found in 1 to 2% of all pregnancies at or around the 18th week (when the big ultrasound is typically done). Ok, so a cyst isn't necessarily bad. In fact Mandy has one of her own in the uterus with the baby right now! Heck, I bet most of us have cysts we don't even know about. The doctor even told us that some experts believe that every baby gets these cysts, some just disappear faster than others. The scary part is that this particular cyst can be an indicator of trisomy 18.
What is trisomy 18? Well, "trisomy" means 3 (tri) chromosomes (somy), and the 18 refers to the 18th chromosome (of the 23 pairs that we normally have). There are three trisomy occurances that one can have a baby born with, trisomy 13, trisomy 18 and trisomy 21. Trisomy 21 is commonly known as Down Syndrome. Three copies of any other chromosome is not at all viable, and these pregnancies don't last past the first trimester. Unlike trisomy 21 (Down Syndrome), trisomy 18 is fatal. Depending upon the severity, the baby may die prior to birth, or very soon after. A very small percentage live past 1 years of age. It is associated with a wide variety of physical deformities and ailments ranging from a cleft lip, or missing thumb, to severe conditions like the stomach not being connected to the esophagous. Needless to say, when the doctor says there is some 'indication' of trisomy 18, we were worried.
Upon further review, there are other indicators. For example, we had a genetic test done which typically screens for 40 to 60% of genetic disorders (like trisomy 18). That test came out negative for us (meaning that there were no signs of any genetic disorder). Comforting, but not conclusive. More significant though, trisomy 18 is often associated with some kind of visible physical problem, like a missing kidney or something. On our ultrasound, they found every single organ where it was supposed to be, and all of the proportions were correct. It's kinda cool, they even estimate the due date of the baby based upon his cranium and femur size. Their estimate from this?... September 15. He is perfectly on schedule.
So, putting all of this information together... the chance of our child having trisomy 18 has been raised from 1 in 3000 (standard chance for all pregnancies) to 1 in 1400. In fact, not a big increase at all. If we wanted, we could get a diagnostic test done (an amniocentesis), which draws genetic material from the womb and looks directly at the chromosomes. The problem is that there is a roughly 1 in 200 chance that simply doing the test will cause a miscarriage. Considering that our baby is more than likely fine, the risk of doing the test is not worth it.
So there you have it. We are not at this time 100% sure that the baby does not have ttrisomy 18, but we are about 99.93% sure, which is pretty dang sure. If you are still worried for us, I recommend you go and build a 1400 sided die, pick a number, and give it a roll... just one roll. Did your number come up? Not bloody likely.
It is said that the cysts typically disappear by the 28th week, and we will look for that. For now, our little guy is looking good, on track for a perfect textbook arrival in September (just like his dad!), and maybe... but we not sure... maybe... starting to kick!