Can I just mention that there are only a certain number of bassinet seats on the aircraft and if there are more infants than bassinets you may not be lucky enough to be assigned one, in which case you would have to have thge baby on your lap. I believe these are assigned on a first come, first served basis (ie. who booked first), or perhaps by card status. Someone with an infant may be able to clarify this for you, or they can through BA reservations.