I read you concern and would like to tell you that I am 51 and have had a port wine on my right forehead all my life. I have two grown sons (30 & 31) and neither of them have a birthmark. So, from someone who knows - the port wine is not necessarily a heriditary trait.
I also had treatments with the Blue Argon Laser at the age of 36, this was of no help. Again the V Beam twice at the age of 38 scarred me (not deeply) and then I went for treatment about 4 years ago using the Sclero laser (not sure if that is spelled right) these treatsment were just okay. I am still looking for the ultimate treatment as this stain is also on my eyelid.
If anyone out there has a good result report for the stain on the forehead/eyelid please let me know. I live in Orlando Florida and am looking for a complete success story. I will never give up if there is something that will help me feel completely better about myself.