Ranma is found to be pregnant.  Worse still she will

not allow herself to be changed back.  Doing that would entail taking a
human life, something well beyond what Ranma is capable of.<<

There's a simple answer to that. Ever heard of the term "surrogate mother"? Someone else (preferably a full-time female) could carry the baby for Ranma. I'm amazed that nobody raised this possibility before.