In July 1933, the Law for the Prevention of Hereditarily Diseased Offspring began to be enforced across Nazi Germany. The policy singled out groups considered unfit to bear children in order to preserve a so-called Aryan purity. Among those targeted were people with physical disabilities, dementia, schizophrenia, the blind, the deaf, and individuals battling alcoholism. The aim was to reduce the birth of individuals deemed defective by the regime.
Law on the Prevention of Offspring with Hereditary Diseases in Numbers
Within two years of the law taking effect, about 1% of Germany’s 17 to 24 year olds were sterilized. Across four years, nearly 400,000 citizens were sterilized through force or coercion.
As the war progressed, enforcement extended to Jews, Roma, and Africans, who faced compulsory sterilization. The regime sought faster, more scalable methods for mass sterilization, given that procedures like vasectomy and tubal ligation were lengthy and expensive.
Researchers pursued new techniques, including radiation, injections, and surgical approaches. Subjects were subjected to the experiments with little regard for consent or safety, and many suffered severe harm.
In some cases, men and women were exposed to X-rays targeting reproductive organs, resulting in burns and lasting damage. Those harmed often became unfit for work and were removed from society in brutal ways.
Another approach involved intravenous injections of iodine and silver nitrate, which caused bleeding, infections, and in some cases cancer of the genital tract. The methods were eventually abandoned due to unacceptable side effects.
Altogether, German physicians deprived around 300,000 concentration camp inmates of the ability to reproduce. The majority of those affected were Jewish and Romani people, many of whom died, contracted infections, or were maimed as a consequence of the experiments.
Psychological studies on reproduction were also conducted. For instance, in Austria, Dr. Hermann Shtiwe examined how extreme stress affected the female reproductive system. Prisoners were told about the date of their possible death and researchers observed changes in the menstrual cycle. Some participants were subjected to sexual violence to explore whether conception could occur under stress. Post-mortem analyses sometimes followed the deaths to compare reproductive organs and conditions with those of healthy subjects.
Dehydration
A 1944 project tested methods to turn seawater into drinkable water. Conducted at the Dachau camp, the research aimed to determine practical ways to sustain soldiers in the field when fresh water was scarce.
Within the study, nearly a hundred Romani individuals were given seawater in place of water and food to observe physiological responses and tolerance under extreme conditions.
Dachau survivor Josef Chofenig later recounted the desperation of the victims, who sought any possible means to obtain fluids. Some examined floors and bedding for moisture, while others searched for a hint of moisture in the environment.
Sewing twins and eye coloration
Experiments on twins were carried out in concentration camps to study hereditary traits and reproductive biology. The research, led by a notorious physician later dubbed the Angel of Death, involved Auschwitz inmates from 1943 to 1944. Approximately 1,500 twin pairs were studied, with only a fraction surviving the procedures.
Techniques included attempting to alter eye color by injecting dye into the irises and testing methods that aimed to create conjoined twins. Many twin pairs developed serious complications and infections, and autopsies were used to compare organ health between twins.
In some cases, pairs were subjected to infection or severe injury, and the findings were used to draw conclusions about broader genetic and developmental questions during the experiments.
Crushed glass and wood shavings in wounds
During 1942 and 1943, at Ravensbrück and nearby facilities, prisoners were wounded and deliberately contaminated with bacteria to replicate battlefield injuries. Crude materials like glass fragments and wood shavings were introduced into wounds to study infection and wound healing under wartime conditions.
The aim was to discover improved treatment methods for combat injuries and to understand how the body responded to severe tissue damage under extreme strain.
The broader context shows how doctors sought to advance military medicine, often at a terrible human cost.
Pressure tests
At Dachau, experiments were conducted to understand how the human body responds to low atmospheric pressure at high altitude. Led by Dr. Sigmund Rascher, the work simulated conditions found at extreme elevations to evaluate pilots’ tolerance and survival strategies.
Rascher documented the results through correspondence with Reichsführer SS Heinrich Himmler, detailing the physiological reactions observed in volunteers subjected to high altitude without adequate oxygen.
The correspondence described severe reactions, including sweating, tremors, convulsions, rapid breathing, and eventual loss of consciousness. The records indicate attempts to revive victims after removing them from the chamber, with some later spared from harsher consequences if they recovered from the experiments.
These accounts reflect a disturbing era when medical researchers pursued dangerous ideas under the banner of national interest, often blurring lines between science and atrocity. [Citation: Historical records and survivor testimonies provide the basis for these descriptions.]