Originally Posted by
SPN Lifer
Obviously children in utero will not yet have a birthdate.
If a FlyerTalker is expecting a baby with a cesarean delivery scheduled on a specific date, perhaps this would be a good opportunity to obtain a data point (DP) on whether the UA MileagePlus sign-up web page accepts a birth date slightly in the future.
"I was a member MileagePlus before I was born!“

When UA has “security” concerns about a MileagePlus account, UA can meddle with the birthday on file so that a member gets newly listed with a birthday from before even UA was born.
Example in the second post by me in the following thread:
MileagePlus account information "updated" weirdly