Choroid Plexus Cyst

So I went in for an ultrasound and it showed my baby had a 3-4 mm choroid plexus cyst on her brain.  The doctor told me not to worry because my triscreen came back fine and heart, liver, kidneys, etc.  look fine.  I've been reading a lot but it still doesn't seem to ease my mind.  What causes this?  Did I do something that caused this?

[LosingMyMindInGA]

No you did NOT do ANYTHING that caused this....it just sometimes happens.  Your doc is most likely right and you have nothing to worry about.  With my youngest daughter, at her 20 weeks scan they found a right choroid plexus cyst....they docs insisted there was nothing to worry about and that it would resolves itself....sure enough by the time I had a repeate scan at 30 weeks...it was completely gone.  She is now a happy, healthy 6 yo without any medical issues aside from the usual colds, etc.