Signs and symptoms of preterm labor include:

• Regular or frequent sensations of abdominal tightening (contractions)
• Constant low, dull backache
• A sensation of pelvic or lower abdominal pressure
• Mild abdominal cramps
• Vaginal spotting or light bleeding
• Preterm rupture of membranes — in a gush or a continuous trickle of fluid after the membrane around the baby breaks or tears
• A change in type of vaginal discharge — watery, mucus-like or bloody

Preterm labor can affect any pregnancy. Many factors have been associated with an increased risk of preterm labor, however, including:

• Previous preterm labor or premature birth, particularly in the most recent pregnancy or in more than one previous pregnancy
• Pregnancy with twins, triplets or other multiples
• Problems with the uterus, cervix or placenta
• Smoking cigarettes or using illicit drugs
• Certain infections, particularly of the amniotic fluid and lower genital tract
• Some chronic conditions, such as high blood pressure and diabetes
• Stressful life events, such as the death of a loved one
• Too much amniotic fluid (polyhydramnios)
• Vaginal bleeding during pregnancy
• Presence of a fetal birth defect
• An interval of less than six months between pregnancies
• Infection of tissues that surround and support your teeth (periodontal disease)

Complications of preterm labor include delivering a preterm baby. This can pose a number of health concerns for your baby, such as low birth weight, breathing difficulties, underdeveloped organs and vision problems. Children who are born prematurely also have a higher risk of learning disabilities and behavioral problems