5 Things You Should Know About Preterm Labor

Previous Termination

Women who have a first trimester abortion by the vacuum aspiration method seem to have no increase in their risk of ectopic (tubal) pregnancy, mid-trimester miscarriage, or preterm delivery compared with women who are experiencing their first pregnancy.

Women who have had a termination by the dilatation and curettage (D&C) method may be at increased risk for ectopic pregnancy, second-trimester miscarriage, or a preterm delivery in subsequent pregnancies.

Physical Activity and Employment

Exercise during pregnancy does not increase the risk of spontaneous abortion or preterm labor. There is evidence that regular exercise may reduce the risk of some complications of pregnancy such as gestational diabetes. A recent summary of the evidence regarding physical activity and pregnancy outcome found that regular exercise may reduce the routine discomforts and symptoms of pregnancy and decrease the length of labor. Similarly, regular exercise continued as a pattern of activity that existed before pregnancy appears harmless. Regular, low-impact exercise is encouraged if no unusual symptoms appear in response to the exercise. Some women have even run marathons during their pregnancy; however, pregnancy is not the time to begin a strenuous, new exercise regimen.

Similarly for most occupations there is little evidence that working during pregnancy causes problems in an uncomplicated pregnancy. Many women continue to work up to the time of delivery. There are reports that women who stand for long periods of time may have a higher rate of preterm delivery. Women who engage in heavy manual labor may or may not be at increased risk of preterm labor. Other reports contradict this conclusion and so the evidence is not clear. It is only common sense that women should not engage in activity that causes severe physical strain or excessive fatigue. The question of whether to work and for how long should be discussed with your doctor.

Exposure To DES (Diethylstilbestrol)

In the 1950s and 1960s, pregnant women were sometimes prescribed a synthetic estrogen hormone, DES, to reduce the risk of miscarriage. Not only was it not an effective treatment, it altered the development of female reproductive organs in the girls whose mothers took DES. Women whose mothers received DES are more likely than other women to have abnormalities of their vagina and uterus that can cause preterm labor. Females exposed to DES as a fetus have a 10 to 30 percent risk of preterm delivery due to structural problems in the uterus, cervix, or vagina and are also predisposed to vaginal cancer.

What Defines a High-Risk Pregnancy?

If you're at risk for preterm labor your doctor may refer to your pregnancy as a high-risk pregnancy. That means your risk of complications such as premature delivery, or other problems with your pregnancy, is greater than that of the general population. Despite having a higher risk, many high-risk pregnancies do not have complications and result in normal labors and deliveries at full-term. Similarly many preterm babies are delivered to women without known risk factors. Risk assessment does not accurately predict preterm delivery; it only estimates risk, and does so imperfectly. At least 50 percent of women who develop preterm labor have no risk factors; however, if you have risk factors for preterm labor, extra precautions and vigilance give you the best chance for a healthy, full-term baby.

It may be frightening to hear that you have a higher than usual risk of preterm delivery, but being aware of the risks, you can take measures to help yourself. There are some well-known factors that increase your risk of spontaneous preterm labor and delivery. If you have any of these factors, you should discuss the situation with your doctor to learn more about your specific risk.