Does oral sex prevent miscarriage? Don't get excited, guys

The notion that oral sex can prevent miscarriage isn’t as far-fetched as it sounds. The idea is that regular exposure to her partner’s semen will make a woman less likely to mount an immunological attack on the baby. Other previous research has suggested that exposure to semen — either through oral or unprotected vaginal sex — was associated with a lower risk of preeclampsia. The plausible underlying explanation for these disparate phenomena is maternal immunological tolerance to the father’s semen.

The current research, which was published in the Journal of Reproductive Immunology, examined 97 women with recurring miscarriages (“cases”) and 137 women without miscarriages (“controls”). They found that women who performed oral sex had 50% lower odds of miscarriage than women who did not. But there are some serious shortcomings in the paper…