Most women expect to give birth to a full-term baby. But sometimes delivery occurs sooner than expected. More than 12 percent of babies in this country are born prematurely -- before 37 weeks' gestation -- and the number of premature births is rising. In fact, it has risen 29 percent since 1981.
Though the causes of prematurity aren't yet fully understood, the latest research suggests that many cases may be triggered by certain bacterial infections and preexisting conditions during pregnancy. While children born before 32 weeks face the highest risk of complications, all premature babies have a risk of developing health problems, such as breathing difficulties, and even learning disabilities. Fortunately, babies born after 35 weeks may suffer few effects.
So how can you reduce your risk? Strive to maintain a healthy lifestyle and attend all prenatal checkups. Knowing what to expect will help ensure that both you and baby get the care you need quickly.
While the majority of premature births result from unexpected, spontaneous preterm labor (often following premature rupture of the membranes), 20 percent are early inductions due to pregnancy complications such as vaginal bleeding; uterine abnormalities; as well as health problems such as high blood pressure, diabetes, and urinary tract infections. In such cases, early delivery may be the safest route for mother and baby. Fortunately, with proper prenatal care, many of these conditions can be treated early on in pregnancy.
New studies also suggest that some cases may be caused by the body's natural response to certain bacterial infections, including those involving amniotic fluid and the tissue surrounding it. Because many of these conditions are often symptomless, they are difficult to prevent and diagnose in pregnancy.
You should also strive to maintain a well-balanced diet to gain the recommended amount of pregnancy weight (25 to 35 pounds for women who begin pregnancy at a normal weight). In fact, studies show that women who have a healthy weight gain in pregnancy are less likely to have a premature baby than women who gain too much or too little. Reducing the amount of stress in your life can also be good for baby; research shows that high levels of stress may increase your chance of having a premature baby. Women who smoke, drink, or use illegal drugs may also have a higher risk of delivering prematurely.
Who's at Risk?
While premature labor can happen to anyone, some women have a greater chance than others from the start. Studies show that women have a higher risk if they are pregnant with multiples (twins or triplets), have had a previous preterm birth, or have certain uterine or cervical abnormalities.
Unfortunately, there are additional inborn factors that may increase your risk of preterm labor. African-American women as well as women younger than 17 or older than 35 are more likely to give birth early.
There are now treatments to help prevent preterm labor in certain high-risk women. Studies indicate that the hormone progesterone, when given in mid pregnancy, can decrease the rate of preterm delivery by 30 percent in women who have had a previous preterm birth. While researchers continue to contemplate whether other high-risk women could benefit from this treatment, the American College of Obstetricians and Gynecologists (ACOG) strongly recommends that progesterone should only be offered to women who've had a previous preterm delivery, as they're the only group of women who have been studied thus far.
Preterm Labor Signs
If you are experiencing signs of preterm labor, your healthcare provider may ask you to go to the hospital for an examination. Once there, you'll probably undergo an internal exam to see if your cervix has begun to dilate, a sign that labor may be starting.
However, sometimes it's difficult for a doctor to tell if you're truly in labor, especially if your cervix isn't dilated. If this is the case, you may need additional tests, including a vaginal ultrasound to get a better look at your cervix, and a vaginal swab to measure levels of a substance called fibronectin.
Fibronectin, a protein produced in early pregnancy, acts as a glue between the fetal sac and uterine lining. When present in late pregnancy (between 22 and 34 weeks), fibronectin may indicate the possibility of preterm delivery. These diagnostic tests can accurately determine which women with contractions are unlikely to deliver in the next two weeks. The good news is that 80 percent of women who show signs of preterm labor don't deliver prematurely.
Treating Preterm Labor
If your doctor believes you are in preterm labor, she or he may attempt to postpone delivery to give your baby more time to grow. Delaying delivery for a few days may not sound like much, but it can make a lifesaving difference for your baby. This extra time can also enable your doctor to make arrangements for you to deliver in a hospital with a neonatal intensive care unit.
Your physician may recommend additional treatments such as bed rest, antibiotics, or intravenous fluids (if you seem dehydrated). Though these options can't completely prevent preterm birth, a group of drugs called tocolytics can now delay delivery for two to seven days. Tocolytics have been shown to be most effective when given early in labor.
If you are less than 34 weeks pregnant, your doctor may suggest treatment with corticosteroids. These drugs work to speed the maturation of your baby's lungs and can significantly reduce the risk of serious complications and death. Corticosteriods are administered as maternal injections and have proven to be most effective when given at least 24 hours before delivery.
If you go into labor after 35 weeks, your doctor may choose not to delay your delivery. Babies born after this time generally do quite well, though they may need some extra medical care during the newborn period.
Chances are, you'll deliver a healthy full-term baby. But it's still important to understand prematurity. Reduce your risk by taking the necessary steps to protect yourself during pregnancy. When it comes to preterm labor, knowing what to expect can make all the difference for you and your baby.
Originally published in American Baby magazine, June 2004.
All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.