Used to describe an ugly ass baby. Some children just aren't cute at all, as unfortunate as that is. So when you spot a really ugly baby, you can claim "UBS", as they're cursed with Ugnaught Baby Syndrome. The word Ugnaught refers to those ugly piglike midgets that froze Han Solo in Carbonite in The Empire Strikes Back.
"That creepy little creature that sneezed on us at Fazoli's definitely had a bad case of Ugnaught Baby Syndrome (UBS). Although God said to love all creatures great and small, I think I've found the exception to that rule."