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Photo of Class, Quetzal

Quetzal Class, PhD

Research Associate Professor, Director Residency Research, Research Division

Department of Obstetrics and Gynecology


Office Phone:

(312) 355-3951

Related Sites:


Quetzal A. Class explores the causes and consequences of preconception, prenatal, and family-planning risk factors on offspring and maternal physical and psychological well-being. Her research has focused on preconception stress, adverse birth outcomes, interpregnancy interval, and maternal infection during pregnancy, primarily using large, longitudinal datasets. Dr. Class uses several advanced statistical and epidemiological methods, such as quasi-experimental approaches, family-based designs (e.g., the comparison of differentially exposed siblings or cousins), and structural equation modeling to pull-apart co-occurring risk mechanisms and test competing hypotheses. Dr. Class is also passionate about research education and very much enjoys mentoring residents as they develop their own research skills and interests.


Medical School - Indiana University, Bloomington

Selected Presentations

Goba, G., Class, Q.A., Barrett, R., Schwartz, J. (April 2021). Prevalence of HPV across Chicago neighborhoods: A multilevel analysis of individual risk factors, geography of structural violence and health disparities. Presentation given at the University of Illinois Cancer Center.

Class, Q.A., (June, 2018). Scientific rigor in studying prenatal cannabis exposure – moving forward, Paper presented at University of Illinois BIRCWH meeting, Chicago, IL.

Class, Q.A., (February, 2018). Using within-family and quasi-experimental approaches to study interpregnancy interval and psychopathological outcomes, Paper presented in the Department of Psychology, University of IL, Chicago.

Class, Q.A., (January, 2018). Prenatal Cannabis Exposure – what we know and how to scientifically move forward, Paper presented at Indiana University, Psychological and Brain Sciences Clinical Colloquium, Bloomington, IN.

Class, Q.A., (October, 2017). Using within-family and quasi-experimental approaches to study interpregnancy interval and adverse birth outcomes, Paper presented in the Department of Psychology at the University of Chicago, Chicago, IL.

Class, Q.A., (March, 2016). Using quasi-experimental and family-based designs to examine pregnancy-related risk factors, Paper presented at OBGYN Grand Rounds at the University of Illinois, Chicago, IL.

Class, Q.A., (November, 2015). Family-based and quasi-experimental studies of pregnancy-related risk factors and offspring health outcomes, Paper presented at the University of Chicago, Chicago, IL.

Class, Q.A., Rickert, M., Larsson, H., Lichtenstein, P., & D’Onofrio, B.M., (August, 2013). Using sibling comparisons to examine the long-term ramifications of low birth weight, Paper presented at Chapman University, Orange, CA.

Class, Q. A., Chan, T., & Bates, J. (June, 2012). Parent Behavior Training, Workshop presented at Circles Initiative Meeting, South Central Community Action Program, Monroe County, Bloomington, IN.