Birth Defects Research

Key points

  • The National Birth Defects Prevention Study (NBDPS) is one of the largest studies on causes of birth defects in the US.
  • NBDPS included deliveries from 1997 to 2011.
  • The Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS) began with deliveries in 2014 and is ongoing.
  • BD-STEPS extends and focuses the efforts of the NBDPS and includes research on stillbirth causes.
Pregnant mom with family talking to doctor

What it is

The National Birth Defects Prevention Study (NBDPS) and the Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS) are studies of risk factors for birth defects and/or stillbirth.

BD-STEPS extends and focuses the efforts of the NBDPS and includes research into risks and potential causes of stillbirth.

These studies are conducted by the Centers for Birth Defects Research and Prevention (CBDRP). The CBDRP are a collaborative group of Centers funded by CDC to study birth defects and stillbirth.

Centers have been established in ten states: Arkansas, California, Georgia, Iowa, Massachusetts, New Jersey, New York, North Carolina, Texas, and Utah. These states had existing birth defects surveillance programs and have expertise in birth defects tracking and research. CDC coordinates the CBDRP and participates as the Georgia Center.

Through the NBDPS and BD-STEPS, the CBDRP has built an infrastructure for birth defects and stillbirth research.

Map shows the different periods that the Centers for Birth Defects Research and Prevention (CBDRP) have participated in CBDRP research studies since 1997. Some centers have participated in only one study, while other centers have participated (and continue to participate) in both studies. New Jersey participated from 1997 to 2003. Texas participated from 1997 to 2011 and began again in 2024. Utah participated from 2003 to 2011. North Carolina has participated since 2003. Arkansas, California, CDC (Georgia), Iowa, Massachusetts, and New York have participated since 1997.
Centers across the nation conduct birth defects and stillbirth research.

Why it's important

CDC works to identify causes of birth defects, find opportunities for prevention, and improve the health of those living with birth defects. Understanding the potential causes of birth defects can lead to improved recommendations, policies, and services. NBDPS and BD-STEPS are critical pieces of CDC's birth defects research.

Importance of NBDPS

The NBDPS is one of the largest studies on the causes of birth defects in the United States. It included over 30,000 interviews of women who had pregnancies affected by birth defects and over 10,000 interviews of women whose pregnancies were not affected by birth defects. Interviews were conducted for women with deliveries from 1997 to 2011.

NBDPS data has been used to make key contributions toward understanding risk factors of having a pregnancy affected by a birth defect, including:

  • Certain medication use by women before and during pregnancy
  • Diabetes and obesity
  • Smoking

Importance of BD-STEPS

The BD-STEPS is a study on risk factors for birth defects and/or stillbirth and began with deliveries on January 1, 2014. It includes interviews of women who had pregnancies affected by birth defects or that ended in stillbirth. It also includes interviews of women whose pregnancies were not affected. Over 6,000 interviews have been conducted so far.

In 2016, CDC expanded funding for the CBDRP's stillbirth work. Understanding the risks and causes of birth defects and stillbirths can help us prevent them. Certain Centers expanded their birth defects surveillance systems to find all pregnancies that end in stillbirth. These programs are:

  • Looking at new ways to find and study stillbirths
  • Interviewing women who lost their baby during pregnancy
  • Finding common experiences and exposures among those women
  • Sharing this information with the medical community and the public

Through BD-STEPS, researchers continue to study possible risk factors for having a pregnancy affected by a birth defect or stillbirth, including:

  • Diabetes and obesity
  • Infections
  • Lifestyle factors
  • Social determinants of health
  • Certain medication use during pregnancy

What's ahead

Interviews for NBDPS were completed in March 2013, but researchers continue to analyze this rich source of information. BD-STEPS interviews are ongoing and data from the study are being analyzed. Researchers have published more than 400 scientific papers using NBDPS and/or BD-STEPS data.

Resources

For information on study questionnaires or how to apply for access to study data, visit NBDPS and BD-STEPS Public Access Procedures.

For more information about CDC's work on stillbirth, visit CDC Activities.