Premature birth

Being born premature is a serious health risk

A full-term pregnancy is 40 weeks of gestation. A premature birth, also called a preterm birth, is one that happens before 37 weeks of completed pregnancy. A very premature birth happens before 32 weeks of completed pregnancy.

Over 5,000 babies a year are born premature in Minnesota. Premature birth is a leading cause of death in the first month of life and contributes to one in three infant deaths. Babies who survive a premature birth face the risk of serious lifelong health problems such as intellectual disabilities, cerebral palsy, breathing and respiratory problems, vision and hearing loss, and feeding and digestive problems. The more premature a baby is, the more severe their health problems are likely to be.

See more information about risk factors for a premature birth at the bottom of this page.

Premature births in MN

Limited to singleton births. * Change in gestational age definition beginning in 2012. Source: Minnesota Center for Health Statistics.

Since 2012, about 7% of babies born in Minnesota each year are premature. Among 2018 singleton births in Minnesota, 7.0% were born premature (before 37 weeks), which was about 4,400 babies. Most of these premature babies were moderate to late preterm (32-36 weeks).

In 2018, nearly 9% of all births in Minnesota were premature, including births of multiples. The data in the chart above is only for singleton births and does not include births of multiples (e.g., twins or triplets). Babies that are multiples are 8 times more likely to be born premature than babies that are singleton births. 

The proportion of premature births in Minnesota is consistently below the U.S. national average. In 2018, 7.0% of Minnesota singleton births were premature, compared to 8.2% nationally.

Premature births in Minnesota by mother's race and ethnicity

Limited to singleton births. Categories are non-Hispanic ethnicity unless noted. Data are for 2014-2018. Source: Minnesota Center for Health Statistics. 

There are racial and ethnic inequities in premature births in Minnesota. Compared to the average rate of prematurity, a mother is more likely to have a premature birth if she identifies as: American Indian, other or unknown race, African American or Black, or Hispanic.

Premature births in Minnesota by mother's age

Limited to singleton births. Data are for 2014-2018. Source: Minnesota Center for Health Statistics. 

In Minnesota, teens and women over age 40 are more likely to have a premature birth compared to the average rate of prematurity for all Minnesota mothers.

Some women have an increased risk of a premature birth

Sometimes a baby is born premature for no known reason. Many women who have a premature delivery have no known risk factors. Risk factors for premature birth are:

  • Carrying more than one baby (twins, triplets, or more)
  • Having a previous premature birth
  • Problems with the uterus or cervix
  • Chronic health problems in the mother, such as high blood pressure, diabetes, and blood clotting disorders
  • Certain infections during pregnancy
  • Cigarette smoking, alcohol use, or use of illegal drugs during pregnancy
  • Exposure to secondhand smoke

Other possible risk factors:

  • A mother's age, race, and income level:
    • Black or African-American women
    • Teenagers and women older than 35 years
    • Low income
  • Late or no prenatal care
  • Stress
  • Exposure to air pollution
  • Exposure to drinking water contaminated with lead


Last updated June 2020.