The growing fetus often causes aches and pains around the ribs due to their position in the womb. Less commonly, medical complications can cause rib pain. The most common causes of rib pain during pregnancy vary by trimester.
Musculoskeletal changes– Changes to your body that occur during pregnancy may cause rib pain. For example, different ranges of motion are limited as your body expands. It’s harder to bend forward because there’s a human being in the front of you. This limitation can cause rib pain.
Pressure from the growing fetus- The growing size of the fetus can result in the rib pain due to the increased pressure.
Hormonal change– During pregnancy, the body produces a hormone called relaxin. This natural hormone is responsible for helping the muscles and ligaments prepare for the birth.
Constipation-Constipation causes abdominal pain and infrequent or delayed bowel movements that can be hard when they occur. Sometimes, a pregnant woman may feel constipation-related pain in the upper abdomen, under the ribs.