Your body knows how to keep your baby safe during pregnancy, starting with the mucus plug. Learn what the mucus plug is, what it does, and when you'll lose it. Medically reviewed by Alyssa Dweck, MS, ...

The cervical os (pronounced like “ox” but with an “s”) is part of a woman's cervix. During pregnancy, the cervix helps keep the growing baby in the uterus, even as he moves closer to the cervical ...