Bernhard Zondek
The gynecologist whose pioneering hormone research led to the first reliable biological pregnancy test, transforming women's healthcare.
1891–1966 (age 75)·Birthday: July 29·The Lost Generation
Biography
Bernhard Zondek, working in Berlin in the 1920s with his colleague Selmar Aschheim, cracked one of medicine's oldest mysteries: how to detect early pregnancy with certainty. Before their work, women relied on uncertain signs or waited months for a physician's confirmation. Zondek and Aschheim discovered that the urine of pregnant women contained high levels of a specific hormone (later identified as human chorionic gonadotropin, or hCG). Their ingenious 'A-Z test' involved injecting a sample into immature female mice; if the woman was pregnant, the hormones would cause the mice's ovaries to mature visibly. This bioassay, published in 1928, was the world's first reliable pregnancy test. Forced to flee Nazi Germany in 1933 because of his Jewish heritage, Zondek rebuilt his life and career in Jerusalem, becoming a founding figure in Israeli medical education and continuing his influential research in endocrinology and gynecology.
The Lost Generation
1883–1900
Came of age during World War I. Disillusioned by the carnage, they rejected the certainties of the Victorian era and built modernism from the wreckage — in art, literature, and politics.
Bernhard was born in 1891, placing them squarely in The Lost Generation. The events that shaped this generation — world wars, depression, and rapid industrialization — shaped the world they entered and the choices available to them.
#1 When Bernhard Was Born
The biggest hits of 1891
Bernhard's Life & Times
The world at every milestone
1891Born
President: Benjamin Harrison
1896Started school
First modern Olympic Games held in Athens
President: Grover Cleveland
1904Became a teenager
New York City opens its first subway line
President: Theodore Roosevelt
1907Could drive
Financial panic grips Wall Street
President: Theodore Roosevelt
1909Could vote
Robert Peary claims to reach the North Pole
President: William Howard Taft
1912Turned 21
Titanic sinks on its maiden voyage
President: William Howard Taft
1921Turned 30
First commercial radio broadcasts
President: Warren G. Harding"My Man" — Fanny Brice
1931Turned 40
The Empire State Building opens as the world's tallest
Gas: $0.17/galPresident: Herbert Hoover"Minnie the Moocher" — Cab CallowayBest Picture: Cimarron
1941Turned 50
Pearl Harbor attack brings the US into WWII
Gas: $0.19/galHome: $3,060Min wage: $0.30/hrPresident: Franklin D. Roosevelt"Chattanooga Choo Choo" — Glenn MillerBest Picture: How Green Was My Valley
1951Turned 60
First color TV broadcast in the US
Gas: $0.27/galHome: $7,925Min wage: $0.75/hrPresident: Harry S. Truman"Too Young" — Nat King ColeBest Picture: An American in Paris
1961Turned 70
Yuri Gagarin becomes the first human in space
Gas: $0.31/galHome: $12,500Min wage: $1.15/hrPresident: John F. Kennedy"Tossin' and Turnin'" — Bobby LewisBest Picture: West Side Story
1966Died at 75
Star Trek premieres on television
Gas: $0.32/galHome: $14,200Min wage: $1.25/hrPresident: Lyndon B. Johnson"The Ballad of the Green Berets" — SSgt Barry SadlerBest Picture: A Man for All Seasons
Key Achievements
- Co-developed the Aschheim-Zondek test, the first reliable biological pregnancy test, in 1928.
- His work provided the foundation for all modern pregnancy tests by identifying the role of hCG.
- Became a professor and director of the obstetrics and gynecology department at the Hebrew University-Hadassah Medical School in Jerusalem.
- Published extensively on hormonal functions and gynecological endocrinology.
Did You Know?
The original Aschheim-Zondek test required injecting a woman's urine into five immature female mice and observing their ovaries days later.
He was forced to leave his position at the Berlin Charité hospital after the Nazi rise to power.
He was the brother of the internist Hermann Zondek.
The test was sometimes colloquially called the 'rabbit test,' though Zondek's original used mice.
“The urine of a pregnant woman makes a mouse's ovaries grow.”
