Premature birth refers to the condition where delivery occurs after the pregnancy has reached 28 weeks but before completing 37 weeks. Premature infants have a very high mortality rate. If a woman experiences prolonged back pain and a hardening of the lower abdomen during this time, it is due to contractions of the uterus. There can also be vaginal discharge of fluids, indicating early breaking of waters. Increased vaginal discharge, sometimes with traces of blood, might also indicate imminent premature birth; medical check-ups and treatment should be sought immediately.