Is it safe to have anal sex while pregnant?

Not recommended.: Pregnancy leads to an increase in the venous pressure around the rectum, which is why many women get hemorrhoids. Anal sex can irritate that, leading to more hemorrhoids or a rectal fissure. Also, anal sex can lead to a release of bacteria in the bloodstream which could cause preterm labor. If you are considering this after pelvic rest for cervical bleeding or previa, it's not a safe alternative.

Yes if gentle: Not the ideal but acceptable if both partners agree.