Dr. Medicine "allows you to replace damaged babies" - why would anybody do that?! Either babies "live to the end" or get removed with shovel to place another.
Proposing a buff: Real healing to randomly picked damaged baby, very slow, 1% hp per 1 sec, when fully healed randomly picks another damaged one.
p.s. or at least make current "replacing" behaviour cost 2x less hearts, so there be any reason to use this at all.