Dear Ms. Ultrasound,
I had an ultrasound this week. I thought I was twenty weeks but measured 17 weeks 5 days. They could not find the lower part of the brain stem.
Should I be concerned? When does this normally form? At how many weeks? I have a appointment with a perinatologist in 3 weeks?
I am going to guess that they could not find what is called the cerebellum on the ultrasound. This is a part of the brain that is routinely measured on an ultrasound in the second trimester. If this was the only part of the babies anatomy that was abnormal or missing, I would not worry too much yet. Usually there are other problems found in the baby if there is a missing part of the anatomy. It seems in your case that the only issue was the cerebellum measurement.
There are a few reasons that this may not have been easily measured, from technical to a large maternal body type to operator inexperience to a real problem.
Soooooooo, take a deep breath and try and relax for now. I believe that a limited amount of stress from Mommy helps the baby and it's development. Once you have your next ultrasound, let me know what they find and we can discuss the findings.
-- Jane RDMS