Is that trying to represent how vulnerable newborn babies are? I think it'd be better if the nr. of hitpoints (if such thing exists) was just low but the health level should display as normal, healthy, whatever. Or did you not intend it to get the health of your last life?
I've noticed that too, I've been reborn into a tiger and it displays:
You are a baby tiger mortally wounded
Is HP allotment at rebirth random? I mean, you may be reborn either healthy or unhealthy, just as there are sickly babies? If that's the case, the meaning is fitting, but if what the "mortally wounded" string is reflecting is the low HP of every baby tiger, it'd be more fitting to say that you're weak or tiny or whatever, or check the wounded state through percentages perhaps.