Preterm Birth
Preterm birth occurs when a baby is born before 37 weeks of pregnancy. (A normal pregnancy lasts about 40 weeks.) Many factors can contribute to this, including maternal age. Preterm birth is of great concern because these babies not only tend to have low birth weights, they are also not fully developed and are not yet ready to be born.
Risks
About 12 percent of U.S. babies are born preterm. The older a woman is, the higher her risk for preterm delivery. Women over 35 are 20 percent more likely to deliver preterm. Multiples almost always deliver preterm. Women who had previous preterm births are at a higher risk, as are women with abnormalities of the cervix or uterus or those who have pregnancies close together. Diabetes also increases your risk of preterm labor.
There may be a relationship between poor nutritional status, zinc and folic acid deficiency, and preterm labor, but a cause-and-effect relationship has not been established. Nonetheless, a good diet, as well as vitamin and folic acid supplements, may help reduce your risk. Recent studies have shown that in women with a prior history, weekly progesterone injections may help reduce the risk of preterm delivery.
Treatment
When a woman goes into preterm labor, her health-care provider will try to slow down or stop the labor by giving her a tocolytic, a medication designed to stop the contractions. The strategy when dealing with preterm labor is to delay it as much as possible. Sometimes it is possible to stop the labor, and in other cases physicians are able to delay the birth. Buying time is important. The primary concern is having enough time to administer drugs (corticosteroids) to improve the baby's lung function.
Babies born preterm may need help breathing and are often low birth weight. Very low birth-weight babies are at risk for brain bleeds. Other problems include heart problems, intestinal problems, vision problems, jaundice, apnea, and anemia. Despite this, the survival rates are quite good for preterm infants.
Of those born at 32 to 35 weeks gestation, 98 percent survive. Babies born at less than 28 weeks are at the highest risk for problems. Of those very preterm babies, 20 to 40 percent develop lasting disabilities. Infants born after 34 weeks, however, have excellent chances and only face possible learning or behavioral disabilities.
