Learning things we never thought we would before.

At the genetic counselor’s office we were explained the science of trisomies and the calculated risk for our situation. We originally thought that the screening test meant there was a pretty much 100% chance we had a baby with trisomy 13. She explained that in fact based on my age upon conception, the age I would be at delivery, and the gestational age of the baby our risk was actually only about 1 in 6 or 14%. Hearing this statistic helped us a bit but we knew we wouldn’t be for sure until we went through the level II ultrasound and then the amniocentesis.

The level II ultrasound, which most pregnant women have done around week 20, would be a very detailed ultrasound that looks at the anatomy of the baby. At this time I was only 15 weeks and 2 days but we were hopeful the ultrasound would be able to confirm or deny any of the trisomy 13 soft markers such as polydactyl (extra fingers or toes), clenched hands, clubbed feet, cleft lip/palate, heart defects, enlarged kidneys, and neural tube defects.

The amniocentesis (amnio) is prenatal test where a small amount of the amniotic fluid is removed for testing. The sample of amniotic fluid is removed through a fine needle inserted into the uterus through the abdomen, under ultrasound guidance. The fluid is then sent to a laboratory for a full chromosome analysis. The amnio can be done between after 15 weeks. The accuracy is about 99.4%. There is a small risk that an amniocentesis could cause a miscarriage (less than 1%, or approximately 1 in 200 to 1 in 400). But at this point the risk of having the amnio done was less than the risk of us having a baby with a trisomy so we knew we had to go through with the testing. 

We decided to proceed with the ultrasound and then based on those results we would then get the amnio done following the ultrasound.