Nazi leaders wanted to redraw the ethnic map of Eastern Europe by eliminating unwanted people. In addition to mass murder and deportation, they also considered mass sterilization as a measure. On 10 July 1942, Heinrich Himmler (via his adjutant Rudolf Brandt) gave permission for the respected gynaecologist Professor Clauberg to test his technique for swift sterilizations on Jewish prisoners. The trials went ahead at the main centre for human experimentation, Auschwitz (which had replaced Ravensbrück as the largest camp for women). The operations caused terrible pain. Some women died, others were killed in order for Clauberg to study their organs.
Dear Professor [Clauberg],
The Reichsführer-SS [Himmler] has today instructed me to write to you and to inform you of his request that, after prior consultation with SS-Gruppenführer [Oswald] Pohl and the camp doctor of the Ravensbrück female concentration camp, you should travel to Ravensbrück to employ your procedure to carry out the sterilization of Jewesses.
Before you begin your work the Reichsführer would like to hear from you roughly how long it would take to sterilize 1000 Jewesses. The Jewesses themselves must know nothing. The Reichsführer considers that you will be able to give the required injection in the course of a general medical examination.[…]
Heil Hitler
Signed: Brandt, SS-Obersturmbannführer
Source: A. Mitscherlich, F. Mielke (eds), Das Diktat der Menschenverachtung (Heidelberg, 1947), pp. 246-7
Translation: Lesley Sharpe and Jeremy Noakes