What can cause pre-term labor?

Q: Will walking a lot and picking up heavy things cause pre-term labor?

A: Routine walking and lifting are not associated with pre-term labor in healthy pregnant women.  However, some physicians may recommend limited physical activity such as running, heavy lifting, sexual intercourse, etc., if a patient has a history of documented risk factors for pre-term labor. In addition, it is never recommended that pregnant women begin new vigorous physical routines that their body hasn't been conditioned to prior to pregnancy.