Resolved Cystic Hygroma, One Umbilical Artery, 3rd Percentile Head Circumerfrence

My baby girl was diagnosed with a very significant cystic hygroma which resolved around 18 weeks but they also found one artery in the umbilical cord. Today at 24 weeks her body is in 30th percentile but her head is in the 3rd percentile. I can only find statistics for one defect alone. I would like some statistics with the combination of the three troubles. We declined Amnio as we want her regardless. But, just what are our chances for mental retardation or Turner's Syndrome or a healthy baby?

[Yao Sun, MD, PhD]

Although cystic hygroma is associated with Turner's Syndrome (having only a single X chromosome), the combination of the 3 problems you describe is not necessarily associated with Turner's.  I am not familiar with a known genetic syndrome with the 3 findings you've described.

Given the combination of ultrasound findings, your baby is at risk for having an underlying genetic problem and subsequent developmental problems.  Once your baby is born, she can have a more detailed evaluation to see if more information can be found to help with a diagnosis or prognosis.  The reason that we talk about "risk" prior to birth is that until more data is known, it is very difficult to state exactly whether or not an infant is likely to have any problems.  There is the possibility that she is "normal", but further evaluation after birth will be helpful to you and your doctors.