Research and Tracking of Zika and Pregnancy

Accurately tracking people with Zika virus infection during pregnancy 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. Information gathered from these systems 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 virus infection during pregnancy
  • Improve counseling of patients about risks during pregnancy
  • Inform best practices for the care of people with Zika virus infection during pregnancy 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 and Infant Registry

Zika in Babies in U.S. Territories

Did you know that some infants with congenital Zika virus infection may not have defects apparent at birth?

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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, infant, and child outcomes. The Registry collects mother-baby linked-longitudinal data – meaning data on mothers and their babies over time to track outcomes and development. The effort is coordinated by CDC in collaboration with state, local, freely associated state, and territorial health departments.

The US Zika Pregnancy and Infant Registry includes data through participation of 64 state, territorial, and freely associated state partners. CDC works closely with health departments to collect data on pregnant people with laboratory evidence of possible Zika virus infection and their infants. The CDC is no longer requesting that health departments actively follow people with Zika virus infection during pregnancy if the pregnancy ended after March 31, 2018. Some health departments may continue to follow these people and securely send this information to CDC.

The Registry will follow infants through age 3 (and up to age 5 in Puerto Rico and USVI). The US Zika Pregnancy and Infant Registry collects pregnancy-related information that is not currently available through standard case reporting, such as when during the pregnancy Zika virus infection occurred, and the outcome of the pregnancy.

Read more about the US Zika Pregnancy and Infant Registry »

Zika Birth Defects Surveillance

Another key component that complemented the US Zika Pregnancy and Infant Registry was the Zika Birth Defects Surveillance (ZBDS) system. ZBDS worked 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.

ZBDS found infants with birth defects using the Zika-associated birth defects that are part of CDC’s standard case definitionexternal icon, including brain abnormalities, microcephaly, eye abnormalities, central nervous system defects, congenital contractures, and congenital hearing loss. This birth defects surveillance component aimed to ensure that no infants with birth defects potentially related to Zika were missed. This innovative surveillance was key to monitoring the full impact of Zika on mothers and babies in the United States.

Pregnant woman with doctor

Understanding Zika’s Impact on Pregnant People 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 collected 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 people 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.