My sister got knocked out while pregnant, help!

Tonight on the way home from work my older sister called me telling me her husband and her got into a huge fight and he punched her in the mouth giving her a fat lip and she said it made her fall down and see stars (not on the stomach just on her butt) we called the cops on him and had that dealt with and she is coming to stay with me. Question is the cops didn't seem too concern that she was pregnant, could this effect the baby should we go to the hospital? I want to but she doesn't think we need to.