Screenwriting : Feedback on my log line? by Alex Davies

Hi Alex, my two cents (or two pence)
I don't understand the concept exactly - is it a horror film? The souls of unborn twins come to life? So the unborn twins don't become born, just their souls??
What happens to their bodies? Do they ever become born?
Also I don't like when a logline has someone "harboring a terrible secret", the concept should be appealing on its surface with what tangibly happens without it promising additional secrets
Then the protagonist wants to save the life of her newborn, okay got that, but the identity? if so then you need to explain briefly why his identity would be in jeopardy - and what do you mean by identity anyway?
Also she "must risk everything" is too vague.
So I really don't understand what your story is about. Not only that, I'm having a hard time even guessing what it's about. And that's not what you want. WHat you want is before you've even finished your full logline, we know what it is - we go "aaah" and smile and we can see the whole movie.
Did the professor "play God" with historical DNA trying to influence her own child and it's gone awry?
Also where does this take place?

The phrase that caught my attention was "life and identity of her newborn son." Lead with that?

Seconding everything Dave said. "come to life" how? "terrible secret" should either be removed or expanded upon "must risk everything etc."... why? There's no clear causality between whatever's going on with these twins and what some professor has to do.

Hmm, seems I have a bit of work to do! Thanks all for your valued comments - it's really helpful to see how the concept can be construed from another POV. "Must risk everything" is lazy on my behalf I must admit, and doesn't actually tally with what happens in the script. I'll give it some more thought and maybe have another crack at a more specific, and less mysterious/unexplained logline!!