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What is preterm birth? Who is at risk, and how can it be prevented?

November 21, 2013

Being pregnant can be one of the most exciting times in a woman’s life, as they anticipate the birth of their little bundle of joy. The hope for all women is that their pregnancy will go to full term, which lasts 40 weeks. However, in some cases, a woman goes into labor and delivers earlier than expected, which is called a “preterm birth.” Preterm birth can be described as any delivery that occurs between 22 and 37 weeks gestation. Preterm birth affects about 12% of pregnant women, a number that has remained essentially unchanged for the past 30 years, despite multiple interventions.

There are two basic categories of preterm birth: spontaneous and indicated. Most preterm births are spontaneous, meaning that they just occur early. However, sometimes a pregnancy may be complicated, and an early delivery is indicated to insure the best possible outcome for the mother and baby (babies). Depending on how early the mother delivers; the baby may be faced with complicated health issues and be forced to stay in the hospital for longer than expected, to ensure the best possible outcome.

How do I know if my pregnancy will result in preterm birth?

Predicting which pregnancy will deliver early is a subject that has been studied and debated for decades. Many reports suggest that a history of a previous preterm birth is the best predictive factor. Others describe low pre-pregnancy weight, poor weight gain, multiple gestations, certain infections and a short cervix as important predictors for preterm birth. In most cases, preterm labor and birth occur unexpectedly in low risk women.

How can preterm birth be prevented?

Even if screening systems were accurate, it is difficult to prevent and treat preterm labor. Over the past 30 years, we have tried and abandoned preventative methods such as: home uterine activity monitoring, oral and subcutaneous tocolytics (treatments to stop uterine contractions), and prophylactic hospitalizations. Recent studies indicate that progesterone supplementation may reduce the chances of preterm labor in selected patients. A cerclage (thread around the cervix) is helpful if the patient has a documented weak cervix (incompetent cervix). Bed rest, pelvic rest and hydration have also been used as common preventative practices for decades, but their effectiveness is unknown.

In summary, the best time for a normal, healthy pregnancy to deliver is at term. However, for those pregnancies that result in preterm birth, the good news is that the overall process of pregnancy and delivery and the science behind these processes have evolved over thousands of years, ensuring that mom’s and baby’s outcome is as healthy as possible.