Lower Part of Brain Stem Missing?


Dear Midwife,
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. What outcome can I expect?


It is very hard for me to say for sure without seeing the ultrasound report, especially since I am not a perinatologist. The brain stem normally forms early, and controls automatic things like heart rate, breathing, etc. If it is really missing, then that is not good news. But I would get a second scan before doing anything drastic. Good luck, and I hope everything works out.

--Cynthia, CNM

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Cynthia Flynn

Cynthia Flynn, CNM. PhD, is the General Director of the Family Health and Birth Center which provides prenatal, birth, postnatal, gynecological and primary health care to underserved women and their families in Washington, D.C. Recently Cynthia served as Associate Professor of Nursing at Seattle University. There she not only taught, but remained in full scope clinical midwifery practice at Valley Medical Center where she cared for pregnant and birthing women, and practices well-woman gynecology, family planning, and treatment of sexually transmitted diseases.

Cynthia founded Columbia Women's Clinic and Birth Center, where she took care of pregnant women and infants up to two weeks of age and attended both birth center and hospital births. Before Cynthia earned her CNM, she worked as a registered nurse in labor and delivery and postpartum and is a certified Doula and Doula trainer.