Oral sex is usually safe as long as the woman’s partner does not blow air into her vagina. Doing so may cause an air embolism – an air bubble that gets trapped in the bloodstream. This is a rare situation, but it can be life threatening for both mother and baby.
Pregnant women should avoid having anal sex. There is greater risk that bacteria could spread from the rectum to the vagina. Also, women with hemorrhoids may find anal sex uncomfortable.