[ConfusedHermit (OP)]

Is there a more or most effective means of non-human mothers giving nutrients to their young before they are born—that don’t have umbilical cords?

For mammals, is the umbilical cord the only thing helping the baby? Will it die without it? Will the mother?

Is it only helping it grow until it’s ready, or do the nutrients from the cord help them get ‘a healthier start’ when it’s born?

Sorry for all the questions; it's packed but I hope to learn the answers for each of them in time :{o~

[Don_1]

Its a question of investment. Perhaps the most successful investors in the future generations are the marsupials.

[CliffordK]

Of course, there is also the duck billed platypus that also breaks all the rules.

The placenta and umbilical cords seems to be efficient enough.  Many animals eat their placenta after birth, so the nutrition in the organ is not entirely lost.  Well, at least pigs will eat it.

So, what the placenta and umbilical cords buy a species is extending the protected in-utero developmental period. 

Sharks (not mammals, of course), have most interesting reproductive systems, with some sharks laying eggs (oviparous), some sharks having egg-like structures developing internally (ovoviviparous), and some with true placentas (viviparous).  Apparently some of the sharks with live birth start eating stuff prior to hatching.

[ConfusedHermit (OP)]

The platypus is such a rebel, man.

Those are some interesting links and facts. Thanks once again :{D~