An authoritative clinical teratology resource to assess risks of medication and other exposures during pregnancy. TERIS was established by Dr. Jan M. Friedman in 1986, and is governed by an advisory board of global authorities in clinical teratology from the fields of medicine, genetics and epidemiology.

TERIS was developed and hosted for over three decades at the University of Washington, a global leader in medical research and education. As of 2025, TERIS has been entrusted to PEAR-Net Society to continue its mission as an independent, nonprofit resource
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TERIS - Teratogen Information System
TERIS is a dynamic resource that contains expert information on the teratogenic risk of over 1,800 medications and other environmental exposures including infections and vaccines. Each agent in the database is accompanied by a summary of the clinical and experimental literature and a teratogenic risk rating. 
While there are several sources of information available on the safety of drug exposures during pregnancy, TERIS is unique in that it is governed by an Advisory Board composed of global authorities from the fields of medicine, epidemiology and genetics. The Advisory Board carefully reviews all agent summaries and teratogenic risk ratings are generated by group consensus. The level of authority provided by TERIS is unmatched in the field of teratogenic risk.
TERIS is used by a diverse range of professionals to inform decision-making around exposures during pregnancy.

For Healthcare Professionals

A wide variety of potentially teratogenic exposures may be encountered during pregnancy, and the state of knowledge regarding the teratogenic effects of drugs and chemicals is constantly evolving. This is important because timely access to high-quality information may reduce prolonged harmful exposures and decrease the number of preventable birth defects.

Many health care providers, including doctors, nurses, genetic counselors, physician assistants, midwives and pharmacists, have limited access to information regarding the teratogenic effects of medications and other environmental exposures. The available data are often highly technical and difficult to interpret and discuss with patients.

For Academic & Pharmaceutical Researchers

Researchers from the pharmaceutical industry and academia use the TERIS database to guide scientific decisions on the maternal-fetal safety of new proprietary compounds. This is important because in 2015, the Food and Drug Administration made the decision to discontinue pregnancy risk letter categories. Since that time, the responsibility for communicating teratogenic risk on biological and pharmaceutical drug labels has shifted back to individual companies.

For Public Health Officials

To improve maternal-fetal health outcomes, public health officials have a critical role in supporting health care providers in counseling and caring for pregnant women by providing them with evidence-based information and educational resources. 

Public health officials can provide TERIS to empower and educate health care providers and their patients on the risks of medications and other environmental agents during pregnancy. TERIS can be distributed to clinics and medical centers that care for pregnant women. Access to TERIS is particularly important for practitioners and counselors who work in underserved or rural areas where immediate access to specialty information may be lacking.
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