Q&A on preterm labor

What are the facts about preterm labor and births?

Preterm birth is defined as those infants delivered prior to the completion of 37 weeks of an expectant mother’s pregnancy. Preterm birth occurs in approximately 12 percent of pregnancies. Preterm births occur spontaneously in the following cases:

  • 40 percent after preterm labor
  • 35 percent after preterm ruptured membranes (when the sac containing the developing baby bursts)
  • 5 percent after other related conditions

What puts a pregnant woman at an increased risk for premature labor?

Attempts to decrease the rate of preterm birth by interventions aimed at individual risk factors have not been successful. It is more likely that multiple risk factors combine to increase the chance of preterm delivery.

Major preterm labor risk factors are: prior preterm birth, multiple gestations, African American race, and low socioeconomic status.

Minor risks include modifiable factors, which are poor maternal weight gain; physically demanding work; smoking; anemia (lack of healthy red blood cells); bacteria in urine not due to contamination from urine sample collection; bacterial vaginosis (where the normal balance of bacteria in the vagina is disrupted and replaced by an overgrowth of certain bacteria); and maternal systemic infections. Nonmodifiable factors are age (younger than 17 and older than 40); prior abortions; DES exposure (a synthetic female hormone); uterine abnormality; short stature; and low pre-pregnancy weight.

What kinds of health risks are posed to an infant who is born premature?

Preterm infants are more likely to experience cerebral palsy, intraventricular hemorrhage (bleeding into the brain’s ventricular system), visual and hearing impairment, chronic lung disease, developmental delay, and poor school performance.

What can an expectant mother proactively do to prevent premature labor?

Prevention of preterm birth remains an elusive goal. However, recent data supports the use of progestational agents (certain drugs) to prevent recurrent preterm birth. Continued research efforts are necessary to better clarify the biology of abnormal childbirth.

What are the symptoms of premature labor?

Symptoms of preterm labor are more than 4 uterine contractions per 20 minutes with cervical dilatation (greater than 2cm in a woman who has never given birth) and cervical effacement (greater than 80 percent).

In a woman with an acute episode of preterm labor, it may be necessary to administer certain medication in a supervised setting, such as tocolysis, antenatal corticosteroids, and antibiotics for Group B streptococcus prophylaxis. All tocolytics allow delay of delivery by 2 days. Delivery after 48 hours of antenatal steroid exposure reduces infant respiratory distress syndrome, intraventricular hemorrhage (bleeding into the brain’s ventricular system), and neonatal death in infants less than 34 weeks.


Dr. Jana Kenaan serves local residents with over 21 years experience as a board-certified Obstetrician and Gynocologist at Bond Clinic. She received her medical degree from the University of Carol Davila School of Medicine in Romania. Dr. Kenaan also serves patients out of Winter Haven Hospital.

Accessibility Toolbar