Caroline May de Costa (; born 1947) was Professor of Obstetrics and Gynaecology at James Cook University, Queensland, Australia, as well as an advocate for indigenous health and abortion rights. She is currently Professor at The Cairns Institute (TCI). She also writes medical nonfiction books and crime novels.
Caroline de Costa was born in Sydney, Australia, where she began studying medicine in 1964 at the University of Sydney, before dropping out to travel after one year. She re-commenced her undergraduate medical studies in Dublin, at the Royal College of Surgeons in Ireland in 1967. Having graduated in 1973, she moved to Papua New Guinea to complete a residency in Port Moresby General Hospital, after which she returned to Ireland to undertake specialist training in obstetrics and gynaecology. She completed her Diploma with the Royal College of Obstetricians and Gynaecologists (RCOG) in 1978, became a fellow of the Royal College of Physicians and Surgeons of Glasgow in 1980, a fellow of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists in 1981, and a fellow of the Royal College of Obstetricians and Gynaecologists in 1990. She obtained a Masters in Public Health from the University of Sydney in 1995 and a PhD from the University of Sydney in 2010. Between 1980 and 1994, she practiced obstetrics and gynaecology first in Port Moresby and then in Sydney.
In 1994, she moved to Cairns where she continued her clinical practice until 2017. From 1994 until 2012, de Costa was part of the outreach specialist obstetric and gynaecological service established by Professor Michael Humphrey through Cairns Base Hospital, providing services throughout Far North Queensland. de Costa is the author of more than 120 research articles, and a number of textbooks. Her principal areas of research have been in reduction of foetal alcohol syndrome in children of indigenous women, vitamin D levels, requirements of pregnant women in Far North Queensland, as well as birth by caesarean section. She completed a PhD at the University of Sydney under the supervision of Dr Hans Pol researching the history of caesarean section births. Her thesis became the subject of a book, Hail Caesar: Why one in three Australian babies are born by Caesarean sections, published in 2008.
de Costa began her work in activism for reproductive rights during her undergraduate medical studies in Ireland, including taking part in the contraceptive train in May 1971 in which members of the Irish Women's Liberation Movement took a train to Belfast, Northern Ireland, to purchase contraceptives and bring them back to Ireland. As part of her specialist training in Ireland, de Costa worked at the Irish Family Planning Association (IFPA) clinics and she notes that she "often travelled back from England with a dozen intrauterine devices discreetly concealed in my bags for IFPA doctors." In Australia, de Costa's active involvement in reproductive rights work was largely within the Royal Australian and New Zealand College of Obstetricians and Gynacologists until 2004, when she became aware of the advantages of the drug mifepristone (RU486), a drug which brings about medical abortion, and which was not available in Australia at that time, despite being available in Europe from as early as 1988 and the US since 2000. She wrote an article in the Medical Journal of Australia advocating for its introduction in Australia, noting "Availability of this drug in Australia might largely overcome many of the inequities of access to abortion, and is critical for many women in rural areas and women in some ethnic groups whose access to surgical abortion is limited."
Subsequently, she was closely involved in bringing about abortion law reform in most jurisdictions across Australia and in the overturning of the Harradine Amendment in the Federal Parliament in 2006, which enabled women's access to medical abortion using mifepristone.
2026 saw the 20 year anniversary of the passage of the legislation that overturned the Harradine Amendment, which made medical abortion available to Australian women. de Costa was invited by the Medical Journal of Australia to write about the progress that has been made since this momentous decision by the Federal parliament. Notably, as of 2026, it was recorded that more than half a million women have used medical abortion since it became available.
de Costa has also advocated for gender equality in research and medical practice, and has published in MJA Insight+ with Professor Nicholas Fisk, highlighting the need to discard terms such as "Bikini medicine" and "Beyond Bikini Medicine'.
In January 2021, de Costa handed back her to the Governor General in protest of Margaret Court, an "internationally acclaimed" former world champion tennis player but now a Christian minister, being advanced to a Companion of the Order of Australia (AC) in the 2021 Australia Day Honours.
Biography