What are the signs of preterm labor?

Preterm labor is often preceded by signs such as lower abdominal pain, increased vaginal discharge, and persistent backache. Many pregnant women experience a dull, menstrual-like discomfort, which could also indicate preterm labor. Regular uterine contractions and hardening of the abdomen may lead to preterm birth. If contractions become regular—occurring at a frequency of 6 or more per hour—preterm labor may occur. Additionally, if there is an increase in vaginal discharge that becomes watery or bloody, prompt medical attention is necessary.