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Health Indicator Report of Preterm Births

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.


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 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 [ 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.


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.


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


Number of live infants born to resident mothers

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 7.6% of singletons are born preterm, more than half of twins and all triplets are born prior to 37 completed weeks of gestation. For very preterm births, the rates are 1.1%, 9.5%, and 39.8%, respectively. New Jersey's overall preterm birth rate has decreased significantly from 10.4% in 2006 to 9.5% in 2017. A similar trend exists for preterm singleton births: a decrease from 8.2% in 2004 to 7.6% in 2017. The very preterm birth rate among all pluralities declined from 1.8% in 2006 to 1.5% in 2017 and, among singletons, the rate declined from 1.4% in 2000 to 1.1% in 2017. Although the preterm birth rate among Black mothers (13.1%) remains much higher than among other racial/ethnic groups (8.3%-9.7%), it is the only group to see a statistically significant decline since 2000 (15.4%). While mother's country of birth does not have a significant effect on preterm birth rates of White and Asian mothers, preterm births are significantly more likely among US-born Blacks and Hispanics compared to their foreign-born counterparts.

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 [ 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

[ CDC Preterm Birth Activities] [ CDC Grand Rounds: Public Health Strategies to Prevent Preterm Birth]
Page Content Updated On 05/14/2019, Published on 05/14/2019
The information provided above is from the Department of Health's NJSHAD web site ( The information published on this website may be reproduced without permission. Please use the following citation: " Retrieved Wed, 25 November 2020 8:36:04 from Department of Health, New Jersey State Health Assessment Data Web site: ".

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