Vaginal bleeding during pregnancy can be scary. However, it isn’t always a sign of trouble. Bleeding in the first trimester (weeks one through 12) might occur, and most women who experience bleeding during pregnancy go on to deliver healthy babies.

Still, it’s important to take vaginal bleeding during pregnancy seriously. Sometimes bleeding during pregnancy indicates an impending miscarriage or a condition that needs prompt treatment. By understanding the most common causes of vaginal bleeding during pregnancy, you’ll know what to look for — and when to contact your health care provider.