I tried to add a birthdate for a Child, as an 'årsdag' (anniversary), and changed the label to the child's name, 'Liv'.
It appeared with Liv / 30th april 2005, and the contact's name in the background - and it showed twice.
I'm not sure how I got the 3rd one now, but I Think twice is already one too much?
If I delete the anniversary, both lines disappear from myCal.
If I add it as other date (not anniversary), I get 2 items in myCal again, this time with
Other / 30th april 1605 (and contact's name grey in the background).
(I would have liked to add the child's birthday, and have it show up in myCal, including the age of the 'anniversary'.
This is not possible at all in iPhone's own calendar, so myCal showing it twice (w/o age) is better than nothing