How do pregnancy tumors in the gums appear and how are they treated?

Red, like a tumor: Due to hormonal changes the gums get inflamed and can get small tumor looking lesions which bleeds. Can treat them with dental cleaning by a dental professional and strict home care. However you might still have it during your pregnancy. Don't worry it will go away after the birth!

Pyogenic granuloma: Pregnancy tumor is a common name for a gingival overgrowth called a pyogenic granuloma. It is a benign localized growth that while usually seen in pregnant women can be seen in anyone. It does need to be removed and submitted for biopsy to confirm that it isn't anything more ominous. I wouldn't recommend just waiting to see if it goes away.

Surgery: If they are causing problems. They are the body's reaction to a source of irritation around the teeth. It is not restricted to pregnant women.