The French doctor and biochemist, Étienne-Émile Baulieu, who has died aged 98, was known as the “father of the abortion pill” for the development of RU486 (mifepristone) in 1980. It blocks the uptake of progesterone, which is essential for a successful pregnancy and, taken with a second drug (misoprostol), triggers a miscarriage. “Medical abortion”, as taking the two pills is known, is faster and more convenient than surgical procedures, and in 2022 accounted for 86% of terminations in the UK.
Baulieu told the German newspaper Die Zeit that when he was in Calcutta in the early 1970s, he was approached by a young woman begging. She had two very young children in tow and cradled a baby in her arms. He could see the baby had died. He told Die Zeit that the moment was pivotal: “The fatalism of extreme poverty and pregnancies! At that moment, I decided to stand up for women to make sure they could make their own decisions about their bodies. It gave meaning to my life as a doctor and researcher.”
At this time, Baulieu, who had made key discoveries about the hormone DHEA, was director of a research unit at Inserm (the French National Institute of Health and Medical Research) and professor of biochemistry at the Bicêtre faculty of medicine at the University of Paris-Sud.
Creating a pill to stop pregnancy had been on his mind for a long time. In 1961 he had discussed with Gregory Pincus, the US inventor of the contraceptive pill, that if a chemical could be found to block the uptake of progesterone in the uterus, it would be impossible for a fertilised egg to embed. Baulieu was able to research a suitable drug at Roussel Uclaf, a French pharmaceutical company that specialised in steroid hormones, where he was a consultant. It was a long road, but in 1980 he identified his antiprogesterone chemical, which the company called RU486 (RU from their initials and 486 because it was the 38,486th substance they had synthesised).
A tortuous path followed to bring the drug to market. Roussel Uclaf underwent a lot of changes in the 70s and the German pharmaceutical giant Hoechst AG became its majority shareholder. Baulieu lobbied the Hoechst management hard to bring RU486 to market, but the chief executive, Wolfgang Hilger, was a devout Catholic and shrank from the adverse publicity it was attracting.
As news of RU486 circulated, hostile articles in the press appeared and letters poured in to Roussel Uclaf. Some called it “a chemical coathanger” and Pope Jean-Paul II denounced it as “the pill of Cain” (referring to the Bible story in which Cain kills his brother Abel). There were demonstrations, and anti-abortionists bought shares in Roussel Uclaf, so that they could attend and disrupt shareholder meetings. Baulieu was likened to Josef Mengele, the Nazi doctor who had conducted hideous experiments in concentration camps. He had to have a bodyguard at public meetings, and at a New Orleans conference he narrowly escaped an assassination attempt, when his talk was rescheduled at the last minute. The bomb intended for him injured another hapless speaker.
Roussel Uclaf dithered during the 80s, submitting but then retracting its application to the French ethics committee to have RU486 licensed for use. In September 1988 the drug was finally approved by the French authorities, but under pressure from anti-abortionists a month later Roussel Uclaf said that it would stop marketing it.
At the time, Baulieu was at the World Congress of Gynaecology and Obstetrics in Rio de Janeiro, Brazil. Incensed, he organised a petition that thousands of doctors at the conference signed, insisting it should be made available to women. The row made newspaper headlines all over the world, and the French health minister Claude Évin intervened, saying in a TV interview that sales of RU486 must resume as the government had approved the drug and it was the “moral property of all women”.
Roussel Uclaf complied and slowly RU486 was licensed in other countries, for example the UK (1991) and Sweden (1992). Baulieu soldiered on, lobbying for it to be licensed elsewhere, including in the US. He stressed it was safer than anything else, telling the New York Times in 1989, “Almost 50 million women have abortions each year, and some 150,000 women die annually from botched abortions. RU486 could save the lives of thousands of women.”
Baulieu was born Étienne Blum in Strasbourg to Léon Blum, a nephrologist, and Thérèse (nee Lion), a lawyer. His father died when he was three and his mother took him and his two sisters, Simone and Françoise, to live first in Paris and then in Grenoble, where he attended the lycée Champollion.
The second world war was well under way and France was occupied by the Nazis. Aged 15, Baulieu and his classmates were committing acts of defiance such as throwing stones at people who worked for the Germans and distributing anti-Nazi leaflets.
One day he spied a couple of men outside a cafe where he was sitting whom he reckoned might be Germans tailing him. Slipping out through a window at the back, he left Grenoble without a word to his family, and met up with undercover French Resistance members in Chambéry in south-east France. False papers were a must, and he changed his name from Étienne Blum to Émile Baulieu (making himself a year older at the same time, so that he could buy cigarettes).
His group mostly ferried weapons, but in 1944 they kidnapped Charles Marion, a prominent officer in the Vichy regime, and executed him. As the youngest, Baulieu was excused from shooting the prisoner, but he was tasked instead with taking photographs of the event.
At the end of the war, Baulieu was reunited with his family and studied medicine and biochemistry at the Université Paris Cité, qualifying in 1955. He had wanted to enrol at medical school under his true name but, as his ID card had “Émile Baulieu”, he had to be enrolled as such, and the name stuck. He preferred to be called Étienne-Émile Baulieu.
Aged 20 in 1947, Baulieu married Yolande Compagnon and had three children: Catherine, Laurent and Frédérique. They remained married until Yolande died in 2015, but for decades lived separate lives.
In the 60s Baulieu socialised with artists such as Andy Warhol and Frank Stella, and had affairs with the film star Sophia Loren and the artist Niki de Saint Phalle. In the 90s he met his long-term partner, Simone Harari, a TV executive, and they married in 2016.
In the late 90s Baulieu retired from Inserm and his university posts, but continued to teach and conduct research for the rest of his life. He was a professor emeritus at the Collège de France and he set up the Institut Baulieu in 2008 as a vehicle for his new research interest: to understand neurodegenerative diseases such as Alzheimer’s. Tau proteins are thought to interfere with brain cell communication; into his 90s Baulieu was working on a way to target them with another naturally occurring protein that he had identified.
In 2003-04 he chaired the French Academy of Sciences and in 1989 won the prestigious Albert Lasker prize. In 2023 President Macron awarded him France’s highest honour: the grand cross of the Légion d’Honneur.
Baulieu is survived by his wife, his three children, eight grandchildren and nine great-grandchildren.
• Étienne-Émile Baulieu (Étienne Blum), doctor and biochemist, born 12 December 1926; died 30 May 2025
