The sudden halting of menstrual periods (amenorrhea) experienced by prisoners at Nazi concentration camps has historically been attributed to the effects of trauma and malnutrition, although new research paints a considerably darker picture. Drawing upon written historical records and interviews with Holocaust survivors, the study authors find evidence that synthetic steroids were added to the food given to female Jewish prisoners in order to hinder their fertility.

“Immediately upon arrival at the concentration camps, over 98 percent of women stopped menstruating,” write the researchers. Addressing this striking statistic in a statement, study author Peggy J. Kleinplatz suggests that such a sudden and uniform effect could not possibly have been caused by stress or starvation. 

"In other horrible mass atrocities in history, this sudden onset of amenorrhea either didn't occur, or occurred slowly in combination with starvation and trauma over a 12- to 18-month period," she said. "So, my question was: What was happening to these women in the death camps that was distinctive, causing it to occur immediately, and couldn't be explained fully by the hypotheses of either trauma, or malnutrition, or both? That was when I began to investigate whether there was some deliberate attempt to cause cessation of menstruation in these Jewish women."

After hearing the testimonies of 93 Holocaust survivors, with an average age of 92, the researchers discovered that all but two developed amenorrhea when they arrived at the camps. “The only women who did not stop menstruating attributed it to detecting something added to the soup on some occasions and refused to eat on those occasions,” they reveal.

One woman, who happened to be menstruating on the day of her arrival, said she was forced to swallow a pill that put an end to her period. This report was corroborated by other survivors who said they saw women being “pulled out of line for pills or injections, leading the women to stop menstruating.”

Another woman who worked in the kitchens at Auschwitz described how packets of “grain-like, very, very light pink chemicals” were added to the soup to ensure that “women don’t get their periods.” 

“This “soup” was distributed to the female inmates only — not to the men and was never consumed by the guards,” the researchers relay.

Further evidence for the use of chemicals disrupting reproductive processes at Nazi camps was found in the documentation presented at the Nuremburg war crimes trial immediately after the Holocaust. For example, correspondence describing a meeting of top Nazi officials at “Führer Headquarters” in July 1942 revealed that the “topic of discussion was the sterilization of Jewesses.” At the meeting, it was decided that “a method should be found which would lead to sterilization of persons without their knowledge,” and that experiments to devise such a scheme would be conducted at Auschwitz.

Compellingly, the researchers say that large quantities of sex steroids were produced in Germany during World War II, raising questions as to why the Nazis would prioritize the manufacture of hormones during wartime. However, since Nazi officials apparently instructed those working on the sterilization of Jewish women not to keep written records, the study authors are unable to discern exactly which chemicals would have been used in the concentration camps.

What they do know, however, is that 98 percent of survivors experienced pregnancy complications after the Holocaust and were unable to have as many children as they would have liked. Of 197 confirmed pregnancies, around a quarter ended in miscarriage while a further 6.6 percent resulted in stillbirths. 

Overall, only 16 percent of study participants were able to carry more than two babies to term, “despite most wanting more children desperately.”

The study was published in the journal Social Science and Medicine.