For Moms

A premature birth, also called a preterm birth, occurs when a baby arrives three or more weeks early – or at less than 37 weeks of gestation. Until recently, doctors have had limited ways to predict which pregnancies may be at risk of delivering early. Today, the PreTRM® Test can provide important information to help predict that risk.

mother laying on bed while holding her baby up
asian mother holding baby close to her chest

What Is Preterm Birth?

A preterm birth is a delivery that occurs any time before the start of the 37th week of pregnancy, typically three or more weeks before the baby’s due date. While not all babies born early face complications, those who are born earlier generally have more severe complications than those born closer to term. While scientists are not certain of all the causes of preterm birth, they are beginning to understand the risk factors that may contribute to a woman’s risk of delivering early.

How Does the PreTRM Test Work?

Most pregnant women can benefit from the PreTRM Test. Your doctor will order the test, and Sera Prognostics will help you find a qualified phlebotomy center to have your blood drawn. Results will be sent directly to your doctor so you can discuss them together.

Do I Qualify for the Test?

Most pregnant women are candidates for the PreTRM Test. Your doctor can help you determine if you qualify.

PreTRM can be used to identify your risk of preterm delivery if you:

  • Are 18 years old or older
  • Are pregnant with a single baby (not twins, triplets, or other multiples)
  • Are not currently showing signs of preterm labor
  • Are not on progesterone therapy after the first trimester of your pregnancy
  • The baby has no confirmed or expected genetic condition or disorder that is associated with shortened gestation

To Learn More

Talk to your doctor

How Do I Sign up for the PreTRM Test?

Only your physician can order the PreTRM Test. If you would like to sign up for the test, speak with your healthcare provider early in your pregnancy.

Once your doctor places the order for the PreTRM Test, Sera Prognostics will help you schedule an appointment with a qualified phlebotomist who will collect your blood sample and ship it to Sera’s laboratory for processing.

Within 7-10 days, your physician will receive the results of your PreTRM Test and will contact you to discuss the results.

What Information Is Provided by the PreTRM Test?

The PreTRM Test report is not a positive or negative (yes or no) result but an “individual risk prediction” of having your baby too early. The test result gives you and your doctor a percentage risk score that represents how high your pregnancy’s risk of delivering early. 

  • General risk of preterm birth for all singleton pregnancies: 7.3%
  • Your individualized risk for preterm birth: X% based on the PreTRM test

The report also compares your personal risk for preterm birth to the average risk of all women pregnant with a single baby. For example, a pregnancy with a 22% individualized risk percentage would be three times as likely as average to deliver before 37 weeks.

With the risk information from the PreTRM Test, along with other vital information from your prenatal visits, you and your healthcare provider can personalize your pregnancy care to optimize your treatment plan and offer the best possible care for your baby.

General risk of preterm birth for all singleton pregnancies1


  1. Martin JA, et al. Births: final data for 2013. Natl Vital Stat Rep. 2015;64(1):1-65.
  2. A Sera Customer Support team member will help you schedule your blood draw between the first day of your 18th week of pregnancy and the sixth day of your 20th week of pregnancy. That’s a 20-day window between days 126 and 146 of your pregnancy.