Wiedemann was born in
Bremen. His father was a medical practitioner. His mother came from a medical family. Wiedemann studied medicine at the
University of Freiburg, the
Ludwig-Maximilians-Universität München, the
University of Hamburg, the
University of Lausanne and the
University of Jena. In 1940, Wiedemann passed the state examination. With a doctoral thesis with
Yusuf Ibrahim he was appointed doctor of medicine in 1941 at the University of Jena. At the University of Jena, he wrote and researched
jaundice. He continued with specialist training in
Bremen,
Bonn and
Münster. As director of the Krefeld Children's Hospital, Wiedemann was one of the first to recognise the fatal side effects of
thalidomide. While initially considered safe, thalidomide was responsible for
teratogenic deformities in children born after their mothers used it during pregnancies, prior to the third trimester. In November 1961, thalidomide was taken off the market due to massive pressure from the press and public.
Kiel University appointed Wiedemann in 1961 as Chairman of
Pediatrics. In 1977, he was chairman of the German Society for Paediatrics Medicine. In 1980, he became professor emeritus. Wiedemann collected and wrote several books about autographs with his wife Gisela von Sybel. Wiedemann died in
Kiel in 2006. ==Honors==