To prevent mismatches between mothers & their babies one could easily use RFID tags designed for the purpose.The infant could wear a very small wristband, more like a bangle, which is embedded with an RFID tag inside.This RFID tag has the same number as the one which the mother wears (also as a wristband or a large bangle).It could be a read only tag, with several data bytes, so there is no question of duplication of numbers at all. One could designate all even numbers as babies and all odd numbers as mothers, for example.Now, when a nurse takes away a baby for its bath or vaccination or whatever, she can bring it back to the mother without any problem as the RFID reader available with the nurse confirms that the baby is indeed returned to its own mother.