How to Prevent Preterm Birth

I often worry when I write about pregnancy-related health news that I'm going to scare mothers-to-be. One pregnant colleague joked that she was afraid to bite into a doughnut after reading an article I wrote on how nourishment during pregnancy may impact a baby's health into adulthood. So, it's with a bit of hesitation that I report on a study published today in the Journal of the American Medical Association. It found that premature babies (defined as those born before 37 weeks of gestation, or more than three weeks before their due date) were at greater risk of dying throughout childhood. The highest risk was observed in those born at or before 27 weeks of gestation; those born more than eight weeks early also had a higher risk of becoming infertile adults, compared with babies born at full term.

These findings are pretty scary stuff, especially given that preterm birth is often difficult if not impossible to prevent. Medications given to halt premature labor, like magnesium sulfate or nitroglycerin patches, often fail to halt labor for more than a day or two. Plus, the problem is getting worse because of the increasing average age of expectant mothers and growing use of fertility treatments, leading to multiple births and medical complications that often end pregnancy early. Preterm births now account for nearly 13 percent of all U.S. births, compared to 9 percent 25 years ago.

Still, the new finding "should be interpreted with extreme caution," says Mary D'Alton, chair of obstetrics and gynecology at Columbia University Medical Center in New York. She tells me that medical care for premature labor has changed very significantly over the past 30 years since the researchers, from Norway, began tracking that country's preterm infants. "It's now standard to give steroid medications to women about to deliver at 24 to 28 weeks, which wasn't the case back then," she explains. Steroids help the baby's lungs mature and reduce the incidence of cerebral palsy, infant death, and chronic health problems.

Though there's no way to guarantee a full-term birth, pregnant women can take certain steps to maximize their odds:

Don't smoke. As the label on the cigarette pack often states, "Smoking by pregnant women may result in fetal injury, premature birth, and low birth weight." And it doesn't help to just cut back on smoking: Recent research suggests you have to go cold turkey. The same goes for cigars, hookah pipes, and the like.

Consider getting progesterone shots if you've had a previous preterm birth. Weekly progesterone injections, administered from week 16 through week 34, can help delay early labor, says Dalton. The trick is identifying women most at risk before they actually go into labor. Women who've already given birth to a premature baby are at greater risk. So, too, are those women who were premature babies themselves, according to the new study.

Curtail activity if your doctor recommends it. Doctors are moving away from recommending bed rest for pregnant women with any kind of problem, says Dalton, but they might recommend it or at least suggest reducing activity if a woman's cervix is short and has begun to dilate early. The jury is still out over whether this can indeed stop premature labor, but it probably can't hurt.

Eat a healthy diet and get a moderate amount of exercise. This can help reduce the likelihood of developing pregnancy-related complications like preeclampsia or gestational diabetes, both of which may necessitate premature delivery if the mother's or baby's health is at risk. Here's what the American College of Obstetricians and Gynecologists recommends for a healthy diet and for exercise.