Quetzal Class

Quetzal Class, PhD

Research Assistant Professor of Obstetrics & Gynecology
Director, Resident Research Program

Academic Office:
Phone: (312) 996-7006
Fax: (312) 996-4238


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.

Recent Publications

Class, QA. Challenges to recent evidence on maternal infection and offspring neuropsychiatric disorder [Invited commentary in Current Best Evidence on “Long-term risk of neuropsychiatric disease after exposure to infection in utero” by al-Haddad et al., 2019]. The Journal of Pediatrics. 2019;210:239-40.

Bramson LM, Rickert ME, Class QA, Sariaslan A, Almqvist C, Larsson H, Lichtenstein P, D’Onofrio BM. The association between childhood relocations and subsequent risk of suicide attempt, psychiatric problems, and low academic achievement. Psychological Medicine 2016;46:969-979.

D’Onofrio BM, Class QA, Rickert ME, Sujan AC, Larsson H, Kuja-Halkola R, Sjölander A, Almqvist C, Lichtenstein P, Oberg AS. Translational epidemiologic approaches to understanding the consequences of early-life exposures.Behavior Genetics 2016;46:315-328.

Class QA, Mortensen PB, Henriksen TB, Dalman C, D’Onofrio BM, Khashan AS. Preconception maternal bereavement and infant and childhood mortality: A Danish population-based study. Psychosomatic Medicine2015;77:863-869.

Sujan AC, Rickert ME, Class QA, Coyne CA, Lichtenstein P, Almqvist C, Larsson H, Sjölander A, Lahey BB, van Hulle C, Waldman I, Oberg AS, D’Onofrio BM. A genetically informed study of the associations between maternal age at childbearing and adverse perinatal outcomes. Behavior Genetics 2016;46:431-456.

Sandman CA, Class QA, Glynn L, Davis EP. Neurobehavioral disorders and DOHaD. In C. Rosenfeld (Ed.), The Epigenome and Developmental Origins of Health and Disease, Academic Press/Elsevier, Waltham MA, 2015.

Class QA, Rickert ME, Larsson H, Lichtenstein P, D’Onofrio BM. Fetal growth and psychiatric and socioeconomic problems: A quasi-experimental population-based study. British Journal of Psychiatry 2014;205:355-361.

Class QA, Abel KM, Khashan AS, Rickert ME, Dalman C, Larsson H, Hultman CM, Långström N, Lichtenstein P, D’Onofrio BM. Offspring psychopathology following preconception, prenatal, and postnatal maternal bereavement stress. Psychological Medicine 2014;44:71-84.

Class QA, Rickert M, Lichtenstein P, D’Onofrio BM. Birth weight, physical morbidity, and mortality: A population-based sibling-comparison study. American Journal of Epidemiology 2014;179: 550-558.

D’Onofrio BM, Class QA, Lahey B, Larsson H. Testing the developmental origins of health and disease hypothesis for psychopathology using family-based quasi-experimental designs. Child Development Perspectives 2014;8:151-157.

McCoy, B.M., Rickert, M.E., Class, Q.A., Larsson, H., Lichtenstein, P., D’Onofrio, B.M. (2014). Mediators of the association between parental severe mental illness and offspring neurodevelopmental problems, Annals of Epidemiology, 24, 629-634.

For a list of Dr. Class’s publications, please click the following link:

Recent Presentations

D’Onofrio BM, Class QA, Rickert ME, Oberg AS, Ginsberg Y, Almqvist C, Larsson H, Lichtenstein P. “Maternal infection during pregnancy and risk for offspring autism: A family-based study”. The Biennial Meeting of the Society for Research in Child Development, Austin TX, April 2017

Class QA. “Using quasi-experimental and family-based designs to examine pregnancy-related risk factors”. Grand Rounds, Department of Obstetrics & Gynecology, University of Illinois, Chicago IL, March 2016.

D’Onofrio BM, Oberg AS, Class QA, Rickert ME, Bramson LM, Almqvist C, Larsson H, Lichtenstein P. “Maternal body mass index and offspring fetal growth: A cousin- and sibling-comparison study”. The Annual Meeting of the Behavior Genetics Association, San Diego, CA, June 2015.

Class QA, Oberg AS, Rickert ME, Larsson H, Lichtenstein P, D’Onofrio BM. “A population-based quasi-experimental study of interpregnancy interval and offspring neuropsychiatric and academic outcomes”. The Biennial Meeting of the Society for Research in Child Development. Philadelphia PA, March 2015.


National Institute of Mental Health (MH094011), “Kirschstein National Research Service Award (NRSA), Individual Pre-doctoral Fellowship”, 2011-2013, Principal Investigator.