Most pregnancies are healthy and without serious problems. However, all women should be aware of the possibility of preterm labor--labor that begins before 37 completed weeks of pregnancy. Preterm labor can lead to preterm birth, which happens to nearly one in eight babies born in the United States. These premature babies are at increased risk for many complications because they are born before their bodies and organ systems have completely matured. Premature babies are often small, with low birthweight (less than 2,500 grams or 5.5 pounds).
Premature babies may need help breathing, eating, fighting infection, and staying warm. Very premature babies, those born before 28 weeks, are especially vulnerable. Many of their organs may not be ready for life outside the mother's womb and may be too immature to function well. Premature babies can have long-term health problems as well. Generally, the more premature the baby, the more serious and long lasting are the health problems.
Risk factors for preterm labor
Although the exact cause of preterm labor is unknown in many cases, women with certain conditions are at greater risk:
- Preeclampsia (also known as toxemia or high blood pressure of pregnancy)
- Chronic medical illness (such as heart or kidney disease)
- Infection (such as group B streptococcus, urinary tract infections, vaginal infections, infections of the fetal/placental tissues)
- Cigarette, alcohol, or drug abuse (such as cocaine)
- Abnormal structure of the uterus
- Cervical incompetence (inability of the cervix to stay closed during pregnancy)
- Previous preterm birth
- Abnormal or decreased function of the placenta or amniotic fluid
- Multiple gestation (twins, triplets, or more)
- Younger than age 17 or older than 35
- Increased stress, or physical, sexual, or emotional abuse
Symptoms of preterm labor
Even if you don't have any of these risk factors, you need to know the symptoms of preterm labor, which include:
- Uterine contractions, especially more than four in one hour
- Menstrual-type cramps
- Pelvic pressure
- Intestinal upset
- Vaginal discharge of blood, mucus, or water
If you notice any symptoms of preterm labor or have concerns about what you are experiencing, call your health care provider as soon as possible, or go to the hospital right away.
Testing for preterm labor
Your health care provider may use the following tests or examinations to determine if you are experiencing preterm labor:
- Uterine contraction monitor. This monitor is used to check the frequency, duration, and strength of your contractions. It has a transducer that is placed over your abdomen with a belt.
- Cervical examination. An examination by a health care provider's gloved fingers of the cervix can help determine if the cervix has softened, shortened, thinned, or dilated (opened), which are all signs of preterm labor.
- Ultrasound. This test is done with a vaginal or abdominal transducer to measure the length of the cervix and to check the fetus and amniotic fluid levels
- Testing for premature rupture of membranes (the amniotic sac)
- Testing for fetal fibronectin (FFN). This is a protein that helps glue together the amniotic sac and the lining of the uterus. FFN may be released when there is a disruption in these tissues or with infection. The protein is then found in cervical secretions where it can be sampled and tested.
Treatment for preterm labor
Treatment for preterm labor depends on many factors, but may include:
- Decreased activity (either at home or in the hospital may be recommended)
- Hospitalization (as specialized personnel and equipment may be necessary)
- Medications (called tocolytics) to help slow or stop contractions. These may be given in an injection or intravenously.
- Corticosteroid medications. These medications may help mature the lungs of the fetus. Lung immaturity is a major problem of premature babies.
- Cervical cerclage. This is a procedure used to suture the cervical opening. Cerclage is used for women with an incompetent cervix, a condition in which the cervix is physically weak and unable to stay closed during pregnancy.
- Antibiotics. Medications used to treat infection.
- Delivery. If treatments do not stop preterm labor or if the fetus or mother is in danger, delivery of the baby may occur. Cesarean delivery may be recommended in certain cases.
By knowing the symptoms of preterm labor and seeking regular prenatal care, you can reduce your risks for preterm birth and the problems of prematurity. Ask your health care provider about preterm labor and your pregnancy.