Principle is one thing. One can state principle without mentioning some partly backed science about how a woman shuts it down. He could have simply said “I don’t support killing a baby regardless of the circumstance”. Problem solved.
What is known about this particular question of science is far less than what is not known.
His comments might have been inaccurate, but I would gues the answer is unclear. What is certain is that nobody can states accurately, based on what they feel about the topic, that Akin was incorrect.
But what Akin said certainly has nothing to do with whether or not he will be a good senator.