My wife was insatiable during each of her pregnancies. In the first trimester, she was not wanting sex at all but into the second as her belly grew and her hormones changed, her pussy would swell up and get puffy and her nipples got hard. She could not get enough cock or cum. I could not keep up with her desire or drive.
We had a young neighbor who lived with his parents down the street. He fucked my wife through three of her pregnancies and she could not get enough of his very big cock. He fucked her the day she delivered on all three, with her starting in labor with contractions shortly after he pumped a big load of fresh cum inside her pussy.
Her obstetrician told her sex was good for starting labor when it was time, she obviously noticed the load of cum leaking from my wife. We never did tell the doctor it was not mine.