Diana Greene Foster

Diana Greene Foster, PhD, is a demographer and professor at the University of California, San Francisco, where she holds a faculty appointment in the Department of Obstetrics, Gynecology, and Reproductive Sciences. Foster also serves as director of research at Advancing New Standards in Reproductive Health. She earned her MA in public and international affairs and her PhD in demography and public policy from Princeton University, following undergraduate studies at UC Berkeley. Foster has developed an evidence-based body of work examining how reproductive health policies impact physical, mental, and socioeconomic outcomes.

Foster is recognized as the principal investigator of the Turnaway Study, a nationwide longitudinal investigation that followed nearly 1,000 women across more than 20 states over a decade. The study compared outcomes for women who received a wanted abortion to those turned away due to gestational limits. Its central finding—that being denied an abortion results in worse financial, health, and family outcomes—has formed the basis of more than 50 peer-reviewed scientific publications and has informed legal briefs at the U.S. Supreme Court. Foster led an interdisciplinary team of psychologists, epidemiologists, sociologists, economists, and public health researchers for the study, and she has authored over 130 scientific papers in journals including American Journal of Public Health, JAMA Psychiatry, and JAMA Pediatrics.

Beyond the Turnaway Study, Foster's research has evaluated the effectiveness of subsidized contraceptives and the impact of dispensing a one-year supply of contraception on reducing unintended pregnancies. Her assessment of Family PACT, California's state family planning program, demonstrated improvements in access to care and reductions in unintended pregnancy rates. Foster also developed a methodology using a Markov model and microsimulation to assess the cost-effectiveness of emergency contraception. She has collaborated with scientists nationwide to study how individuals navigate state abortion laws and has led a Turnaway Study in Nepal.

Foster's research is presented in the book "The Turnaway Study: Ten Years, a Thousand Women, and the Consequences of Having — or Being Denied — an Abortion." The Turnaway Study has inspired a lecture series and a play, extending its influence beyond the scientific community. Foster delivered a TED Talk on the study's findings at the TEDWomen conference, sharing her research with a broad public audience. She was named one of ten people who shaped science by Nature and was selected as a MacArthur Fellow, receiving the "Genius Grant." Foster's work provides clinicians, policymakers, and the public with evidence to understand the consequences of reproductive healthcare access.