I recently heard on the channel that always does those Baby Story shows... that there are a few cats that really take a maternal instinct to infants. So as a result, they will lay on top of or extremely close to the baby to protect and to keep him/her warm.
As I mentioned in another thread, my doctor told me it really was a hit or miss. If your kid was going to get asthma,... the cat may trigger it. However, all of the doctors in family practice say they would avoid letting the 2 sleep together BUT don't see anything wrong with it if mommy and daddy aren't allergic. Their concerns had nothing to do with the cat sleeping too close. They said that if the parent is there, they imagine you can learn how the cat will react to it.
The asthma "triggering" ....can happen up to the age of 2. This made me feel a little better about putting the 2 together when they are in the living room. Meaning.. I don't freak if the cat tries to walk by and smell baby. That's a long time to keep cat and baby apart. Though for my baby (so young) ...doctor said he's too young at the moment to even be triggered by any allergy.