Interesting, thanks. You make it sound like it's about postnatal depression ("the monster isn’t intolerably, fundamentally, stomach-turningly repulsive until that spark of life enters it"). Definitely food for thought.
Yeah, the protagonist’s a guy (Shelley was raised by her dad…) and the he-does-it-with-science thing is definitely there (though he’s nothing at all like the mad scientist from the films) but I do think the book leans much more strongly toward motherhood (and especially pregnancy and birth) than fatherhood, themes-wise, though it’s definitely not the only thing going on, either.