Definition

Percent of live born infants born before 37 weeks (preterm) or before 32 weeks (very preterm) of gestation based on obstetric estimate Preterm is synonymous with premature. Infants born before 37 weeks of pregnancy are considered preterm and those born before 32 weeks of pregnancy are considered very preterm. Infants born at or after 37 weeks of pregnancy are called full term. Most pregnancies last around 40 weeks.

Numerator

Number of live born infants born before 37 weeks (preterm) or before 32 weeks (very preterm) of gestation based on obstetric estimate

Denominator

Number of live infants born to resident mothers

Data Interpretation Issues

The New Jersey Department of Health has been using the obstetric estimate (OE) to determine gestational age since 1989, while the National Center for Health Statistics (NCHS) had been calculating it using date of last menstrual period (LMP). In 2003, NCHS changed the standard for gestational period from the LMP-based gestational age to the OE-based gestational age. OE-based gestational age for U.S. data became available for years 2007 and later in February, 2016. Data in reports published prior to February, 2016 will not match data shown here. Refer to [http://www.cdc.gov/nchs/data/nvsr/nvsr64/nvsr64_05.pdf Measuring Gestational Age in Vital Statistics Data: Transitioning to the Obstetric Estimate] for more information. [[br]][[br]] The annual number of birth records with unknown gestational age was between 5,100 and 6,700 in 2000-2009. Unknown gestational age dropped to 1,000-2,800 records per year in 2010-2014. In recent years, improved data exchange between states has resulted in fewer than 100 NJ resident birth records with unknown gestational age each year. A large number of "unknowns" in the denominator may artificially decrease rates.

Why Is This Important?

Prematurity increases the risk for infant morbidity and mortality. Infants born preterm are at greater risk of dying in the first month of life. Preterm infants may require intensive care at birth and are at higher risk of developmental disabilities and chronic illnesses throughout life. They are more likely to require special education services. Health care costs and length of hospital stay are higher for preterm infants. The more preterm an infant is born, the more severe the health problems are likely to be.

Healthy People Objective: Reduce preterm births

U.S. Target: [[br]]Preterm (<37 weeks): 11.4% [[br]]Very preterm (<32 weeks): 1.8%

How Are We Doing?

Preterm birth is highly correlated with plurality. While 7.8% of singletons are born preterm, more than half of twins and nearly all triplets are born prior to 37 completed weeks of gestation. For very preterm births, the rates are 1.1%, 10.8%, and 28.2%, respectively. New Jersey's overall preterm birth rate has decreased from 10.4% in 2006 to 9.5% in 2017-2019. The very preterm birth rate among all pluralities declined from 1.8% in 2006 to 1.5% in 2017-2019 and, among singletons, the rate declined from 1.4% in 2000 to 1.1% in 2019. The preterm birth rate among Black mothers (13.8%) remains significantly higher than among other racial/ethnic groups (8.3%-9.9%).

How Do We Compare With the U.S.?

New Jersey's preterm and very preterm birth rates for singletons and for all pluralities are slightly below those of the nation as a whole.

What Is Being Done?

The [http://www.nj.gov/health/fhs/ Division of Family Health Services] in the New Jersey Department of Health administers programs to enhance the health, safety and well-being of families and communities in New Jersey. Several programs are aimed at improving birth outcomes.

Evidence-based Practices

[https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pretermcdc-activities.html CDC Preterm Birth Activities] [https://www.cdc.gov/mmwr/volumes/65/wr/mm6532a4.htm CDC Grand Rounds: Public Health Strategies to Prevent Preterm Birth]

Data Notes

Gestational age groups based on the obstetric estimate (OE) are not available before 2007 for U.S. data. Confidence intervals are not available for U.S. data.

Data Notes

This is an Environmental Public Health Tracking (EPHT) indicator. [[br]][[br]] Gestational age groups based on the obstetric estimate (OE) are not available before 2007 for U.S. data. Confidence intervals are not available for U.S. data.

Data Notes

Data for White, Black, and Asian do not include Hispanics. Hispanic ethnicity includes persons of any race.

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Notes

Data for White, Black, and Asian do not include Hispanics. Hispanic ethnicity includes persons of any race. [[br]] Confidence limits are not available for US data.

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Notes

Terminology: *Preterm = births before 37 weeks of gestation *Early preterm = births before 34 weeks of gestation *Very preterm(1) = births before 32 weeks (if "extremely preterm" is not examined separately) [[br]] *Extremely preterm = births before 28 weeks of gestation *Very preterm(2) = births between 28 and 31 weeks of gestation *Moderately preterm = births between 32 and 33 weeks of gestation *Late preterm = births between 34 and 36 weeks of gestation

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Notes

Very preterm birth among singletons is an Environmental Public Health Tracking (EPHT) indicator.

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Notes

This is an Environmental Public Health Tracking (EPHT) indicator.

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

Data Notes

Very preterm birth among singletons is an Environmental Public Health Tracking (EPHT) indicator.

Data Source

Birth Certificate Database, Office of Vital Statistics and Registry, New Jersey Department of Health

References and Community Resources

Measuring Gestational Age in Vital Statistics Data: Transitioning to the Obstetric Estimate: [http://www.cdc.gov/nchs/data/nvsr/nvsr64/nvsr64_05.pdf] Preterm Birth: [https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pretermbirth.htm] National Center for Health Statistics Birthweight and Gestation Fast Stats: [https://www.cdc.gov/nchs/fastats/birthweight.htm]