Researchers at the University Children's Hospital Zurich and Zurich University will examine cases from 1945 to 1970, taking into account the perspectives of medical staff as well as patients.
Since 1950 operations and medication have been used to give a gender to kids whose genitalia are not clear at birth.
This policy has now come under fire, the Swiss news agency SDA reported.
To shed light on its own practices, the hospital is to examine its files in a two-year study financed by the Swiss National Science Foundation (SNSF), it was reported on Monday.
The idea is to build on a pilot study from 2014 that was prompted by a self-help organization for those affected, zwischengeschlecht.org.
The organization campaigns for an end to forced sex operations on children.
It says that one in every 1,000 babies has “ambiguous, atypical or unusual physical sexual characteristics”.
Since the 1950s the Children's Hospital Zurich has been considered a leader in the field of research into and treatment of the phenomenon of intersexuality.