by Tom Walsh

In the last 25 years, the number of premature births has increased by more than 30 percent.

We've all seen the photographs in the news: Newborns tiny enough to be cradled between their mother's hands, newborns in incubators hooked up to multiple machines and monitors. In recent years, doctors have saved babies born almost four months early, who weigh under two pounds. More of these premature babies are surviving than ever before.

Yet there are also more premature births than in the past. In the last 25 years, the number of premature births has increased by more than 30 percent. In 1981, the rate of premature births was 9.4 percent. By 2005, it had risen to 12.7 percent. And healthcare professionals aren't sure why.

"There is no simple answer to explain why it's increasing," says Linda DiPalma, Director of Program Services for the Rhode Island chapter of the March of Dimes, the national agency dedicated to giving "every baby a healthy start."

Not a healthy way to arrive
Most pregnancies last about 40 weeks, and babies born between 37 and 40 weeks are considered "full term." Babies born before 37 completed weeks are considered premature.

Arriving in this world ahead of time can lead to health difficulties throughout life, including mental retardation, cerebral palsy, lung and gastrointestinal problems, vision, hearing loss, and sometimes even death. All premature babies are at risk for health problems, according to the March of Dimes. The highest risk, though, is with those born before or during 33 weeks of gestation.

"Despite great strides in improving the survival of infants born preterm, little is known about how preterm births can be prevented," said Richard E. Behrman, chair of a committee that authored a 2006 Institute of Medicine (IOM) report. Behrman's committee concluded that, "Any significant gains to be made in the study of preterm birth will be in the area of prevention."

DiPalma agrees. "We know there are certain factors that influence premature births," she says. "We have the correlations, but not the cause."

This much is known:

• About 25 percent of preterm births result from doctors inducing labor early or performing a caesarean delivery due to pregnancy complications or health problems in the mother or the fetus. In most of these cases, early delivery is the safest strategy for mother and baby.
• Most preterm births result from spontaneous preterm labor, either by itself or after spontaneous premature rupture of the membranes (PROM) when the sac inside the uterus that holds the baby breaks too soon.
• Certain medical conditions may increase the chances of premature delivery, such as infections, high blood pressure, diabetes, clotting disorders, and being underweight or obese before pregnancy.
• Three groups of women are most at risk: Those who have had a previous preterm birth, those who are pregnant with twins, triplets, or more, and women with certain uterine or cervical abnormalities. Even with this knowledge, there is still no way for a doctor to predict which women will deliver prematurely.

Lifestyle plays a role
Doctors have determined that certain lifestyle factors may heighten a woman's risk of delivering prematurely, according to the March of Dimes. These include late or no prenatal care, smoking, drinking alcohol, using illegal drugs, exposure to the medication DES (diethylstilbestrol), domestic violence, lack of social support, high levels of stress, and long working hours that include significant periods of standing. Although having one or more of these risk factors doesn't mean a pregnant woman will have preterm labor, it's important for her to talk to an obstetrician about any risks she may have.

Important steps to take
So what can women do to protect themselves and their babies? "Women of child-bearing age must take care of their health," DiPalma says. "These issues matter very early on. Women who don't know they are pregnant may engage in risk factors that are dangerous to babies. Prenatal care and women's health overall are important."

These steps can help women prevent premature birth and other complications with pregnancy:

• Visit your doctor regularly during your pregnancy. If you are thinking about getting pregnant, it's a good idea to talk to your doctor first.
• Eat a healthy diet. Talk to your doctor about taking a prenatal vitamin, to make sure you are getting enough folic acid and other nutrients.
• Don't smoke, drink alcohol, or take drugs. Ask your doctor before taking any prescription or over-the-counter medication.
• If you have a health condition such as diabetes or asthma, talk to your doctor about how to best manage your condition.
• Brush your teeth at least twice a day and floss daily. Also, visit a dentist for regular cleanings. Gum disease may be associated with preterm birth.

For more information on premature birth, please visit the March of Dimes.