A full-term pregnancy lasts about 40 weeks. Preterm labor occurs when contractions begin to open your cervix before 37 weeks of pregnancy.

If preterm labor can't be stopped, your baby will be born early. The earlier premature birth happens, the greater the health risks for your baby. Many premature babies (preemies) need special care in the neonatal intensive care unit. Preemies can also have long-term mental and physical disabilities. In addition, giving birth prematurely increases your risk of preterm labor in future pregnancies.

While the specific cause of preterm labor often isn't clear, certain risk factors can increase the risk of preterm labor. Find out if you're at risk of preterm labor and what you can do to prevent it.

Feb. 24, 2012