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CDC Preterm Birth Activities

CDC scientists are collaborating with many partners, including state health departments, university researchers, and other health care professionals to understand why preterm births occur and what can be done to help prevent them. CDC’s Division of Reproductive Health is engaged in the following activities:

Perinatal Quality Collaboratives 

CDC scientists, in collaboration with our partners, are working to understand the multiple reasons for preterm births and advance new strategies for prevention. CDC provides support to state Perinatal Quality Collaboratives (PQC) initiatives in California, New York, Illinois, Massachusetts, North Carolina, and Ohio. State Perinatal Quality Collaboratives (PQCs) are networks of perinatal care providers and public health professionals working together to implement best practices such as real-time reporting of perinatal clinical quality metrics (e.g., elective deliveries less than 39 weeks of gestation, administration of antenatal steroids [medication given before birth to speed up a baby’s lung development]) in an effort to prevent prematurity and improve outcomes for infants born too early and too small.

One of the goals of CDC’s work with PQCs is the dissemination of strategies used by high-functioning PQCs to states in various stages of development. In partnership with CDC-funded collaboratives, the Division of Reproductive Health hosts regular Webinars that allow PQCs to share strategies related to their development as well as specific perinatal quality improvement initiatives. Recordings of previous Webinars are archived and available for viewing.

Vitamin D Studies

VitaminsVitamin D inadequacy (<50 nmol/L) is estimated to affect about 38% of U.S. reproductive-aged women and 28% of U.S. pregnant women. Among pregnant women, vitamin D deficiency varies significantly by racial and ethnic groups, ranging from 13% of non-Hispanic white women to 80% of non-Hispanic black women. Women who have low levels of vitamin D may be at higher risk for problems during pregnancy, including preterm birth, but more research is needed to clarify the relationship between pregnancy problems and vitamin D. CDC conducted a study in Michigan, North Carolina, and Washington State to examine vitamin D levels in stored blood samples of women who had a preterm birth. An additional analysis confirmed seasonal changes in levels of 25-hydroxyvitamin D (a substance used to measure vitamin D status), with peak levels in summer and the lowest levels in winter. However, there are smaller seasonal changes among black mothers. CDC also funded researchers at the University of Pittsburgh to conduct a study examining whether vitamin D deficiency and variations in vitamin D receptor genes are associated with risk of preterm birth in pregnant women.

Smoking in Pregnancy

no smoking signDespite decreases in smoking prevalence over recent years, about 19% of women of reproductive age are smokers (2009 data), and about 10% of women reported smoking during pregnancy in 2011 (25 states). In addition to a variety of negative pregnancy outcomes, smoking during pregnancy is associated with 5%-8% of the cases of preterm birth. CDC is actively working to improve reproductive health outcomes through the reduction of smoking among women before, during, and after pregnancy in the United States and globally. Learn more about CDC’s work on tobacco use in pregnancy.

Surveillance, Data Quality, and Data Linkages

image of bar graphsMuch of CDC’s maternal and infant health surveillance, data quality improvement, and data linkage efforts revolve around birth certificates, the primary resource for learning about preterm birth rates in the United States. CDC partners with the National Center for Health Statistics (NCHS) and the National Association for Public Health Statistics and Information Systems (NAPHSIS) to promote the accurate recording of gestational age on birth certificates, that is critical to calculate the rate of preterm birth, better understand the impact of preterm birth, follow trends, and make recommendations about preventing preterm birth. CDC is also involved in data linkage projects for the jurisdictions of NYC and Kansas that link together birth certificate data with other administrative or survey data, including fetal death certificates, hospital discharge records, and Pregnancy Risk Assessment Monitoring System survey data.

Additional Sources of CDC Preterm Birth Data

Assisted Reproductive Technology (ART) Surveillance

2012 national summary report coverThe CDC National ART Surveillance System (NASS) is a nationwide system for monitoring ART use and outcomes. Analysis of NASS data has supported the evidence suggesting a higher risk for certain adverse outcomes, including preterm birth, among women who use ART.

Pregnancy Risk Assessment Monitoring System

PRAMS logoThe Pregnancy Risk Assessment Monitoring System (PRAMS) is a surveillance project of the CDC and state health departments. PRAMS collects state-specific, population-based data on maternal attitudes and experiences before, during, and shortly after pregnancy. PRAMS data have been used to analyze the characteristics of women who experienced preterm delivery.

National Center for Health Statistics (NCHS)

CDC’s NCHS is the principal health statistics agency of the United States.  Through its relationship with vital registration systems throughout the United States, NCHS collects, analyzes, and publishes data on a wide range of health indicators, including preterm birth. For more information, visit the NCHS birth data page.


State-Based Efforts

MCH Epidemiology Assignees

MCH logoThe Maternal and Child Health Epidemiology Program (MCHEP) assigns senior CDC epidemiologists and graduate-level fellows to state health departments and other public health agencies and organizations, where they focus on MCH epidemiology capacity building and applied research. The MCHEP has assigned more than 35 senior CDC epidemiologists focused on MCH epidemiology capacity building and applied research to 20 states since 1987. Assignees provide direct assistance to public health agencies on a variety of topics, including preterm birth.

Strong Start Initiative

The Department of Health and Human Services launched the Strong Start Initiative to increase healthy deliveries and reduce preterm births. To tackle this problem, the Center for Medicare and Medicaid Innovation awarded grants to health care providers and community organizations to improve prenatal care to women covered by Medicaid or Children’s Health Insurance Program (CHIP). CDC is one of the federal agencies that developed Strong Start’s goals and focus and continues to provide initiative support.

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