To think about your question in another way, does anything you eat end up in your reproductive system and in the same form as it was consumed?

Luckily not.

When you swallow semen, or anything else for that matter, it begins to digest in the mouth, then in the stomach, and so on, until whatever cannot be utilized by the body is excreted. Sperm will die from its breakdown through the gastrointestinal (GI) tract. But even if sperm lived, your mouth does not directly lead to your reproductive system; therefore, it is impossible that swallowing ejaculate during oral sex will make you pregnant.

However, I caution that you are at risk for sexually transmitted diseases (STDs), if your partner is infected. To reduce your risk of contracting or transmitting STDs, you and your partner should practice safer sex techniques, such as using an oral or dental dam during oral sex. Also read the archive, for more information.