Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Research and Tracking

Accurately tracking pregnant women with Zika virus infection and their fetuses and infants can help answer the many questions about Zika virus infection during pregnancy. CDC set up systems to understand the potential impact of Zika virus infection during pregnancy, which can lead to recommendations, policies, and services to help prevent Zika and serve affected families.

Importance of Collecting Data about Zika Virus and Its Effects

Public health data about Zika virus infection during pregnancy are used for the following purposes:

  • Address questions about timing, risk, and the spectrum of outcomes linked with Zika during pregnancy
  • Improve counseling of patients about risks during pregnancy
  • Inform best practices for the care of pregnant women with Zika virus infection and their infants
  • Identify and refer children for services they need as early as possible
  • Help agencies prepare to provide services to affected children and families
  • Inform policies to allocate resources and services to help affected children and their families
  • Improve prevention of Zika virus infection during pregnancy

US Zika Pregnancy & Infant Registry

Mother holding little baby girl

The US Zika Pregnancy and Infant Registry (the “Registry”) is an enhanced national surveillance effort to monitor the effect of Zika virus infection during pregnancy on fetal and infant outcomes. The effort is coordinated by CDC in collaboration with state, tribal, local, and territorial health departments.

The US Zika Pregnancy and Infant Registry includes data from all states and territories. CDC works closely with states and territories to collect data on pregnant women with laboratory evidence of possible Zika virus infection and their infants. The CDC is no longer requesting that health departments actively follow pregnant women with Zika virus infection if the pregnancy ends after March 31, 2018. Some health departments may continue to follow these women and securely send this medical information to CDC.

The Registry plans to follow infants through at least their second birthday in as many jurisdictions as possible. The US Zika Pregnancy and Infant Registry collects pregnancy-related information that is not currently available through standard case reporting. This information includes data like when during the pregnancy Zika virus infection occurred, other potential exposures during pregnancy, and the outcome of the pregnancy. The Registry also collects longitudinal data– meaning data on mothers and babies over time to track outcomes and development.

Read more about the US Zika Pregnancy and Infant Registry »

Zika Birth Defects Surveillance

Another key component that complements the US Zika Pregnancy and Infant Registry is rapid birth defects surveillance. This component works to identify all infants with birth defects potentially related to Zika virus, regardless of whether there was Zika virus exposure or laboratory evidence of Zika. The Zika-associated birth defects that are part of CDC’s standard case definition include brain abnormalities, microcephaly, eye abnormalities, central nervous system defects, congenital contractures, and congenital deafness. This birth defects surveillance component aims to ensure that no infants with birth defects potentially related to Zika will be missed by the system. This innovative surveillance is key to monitoring the full impact of Zika on mothers and babies in the United States.

Read more about Zika Birth Defects Surveillance »

Programs and Research to Protect Mothers and Babies

Zika Local Health Department Field Support
Pregnant woman with doctor

To reduce the effect of Zika on mothers, their babies, and their communities, CDC launched the Zika Local Health Department Initiative (LHDI), which places highly qualified local field staff in local health departments. This initiative aims to build capacity and improve Zika pregnancy and birth defects surveillance, increase referral to medical and social services, and enhance provider and community outreach. Twenty-seven jurisdictions, primarily in areas with high risk of local transmission and/or with a high volume of travel-associated cases, receive field assignee support.

Understanding Zika’s Impact on Pregnant Women and Infants Globally

CDC’s National Center on Birth Defects and Developmental Disabilities is conducting similar tracking and research studies abroad, in collaboration with governments in Colombia and Brazil. CDC is collecting additional information about the long-term health outcomes of infants with congenital Zika virus infection in order to protect mothers and babies in the United States and around the globe. Understanding all of the ways that Zika virus infection affects pregnant women and infants is an important part of our defense against Zika virus and will help the US prepare for the long-term challenges posed by Zika.

For more information, please visit Understanding the Impact of Zika during Pregnancy Globally.