Conversation: The conversation between human and AI assistant.
[|Human|] my sister is about 10weeks preganant she had an U/S. Her OB called her and told her they found a mass on the back of the neck of the baby. She is still waiting to get an appt with a specialty doctor, but what does it mean when a baby has a mass in pregnancy.. thank you Sonia
[|AI|]  Hello Sonia and welcome to Chat Doctor. The common causes of a mass on a fetus neck are meningococcal (abnormal spinal cord protrusion), cystic aroma (abnormal protrusion of lymph vessels), lipoma (non-cancerous growth of a tumor). All the causes mentioned above are treatable but may require surgery after birth of the baby. I could have given a more detailed answer if I had few more facts like age of the parents, any chromosomal abnormality suspected in the fetus etc. Please do write back if you have any more queries.