IMDb permits the removal of birth names from a person's biographical details if the birth name is not broadly publicly known (i.e. it's not already widely recognized and available elsewhere through sources such as major reference sites or publications) and if the person no longer voluntarily uses it (i.e. only uses their birth name when compelled to do so by government/legal requirements, but not in other aspects of their daily or professional life).
If you no longer voluntarily use the birth name listed in connection with your IMDb name page in a public or private capacity and would like IMDb to remove your birth name from your IMDb biography page, please contact IMDb’s Customer Support for details on how to provide documentation to verify your identity and other information in support of your request (select IMDb Fan/Contributor questions > Names & biographical Data > Other name and bio data issue, then select "Email").
Only requests for removal of birth names listed in biographical data will be reviewed. For birth name removal requests pertaining to titles in which a person was credited on-screen as their birth name, their credited name will remain listed in the credits section of applicable IMDb name and title pages in parentheses. This is in order to continue providing IMDb’s hundreds of millions of customers worldwide with comprehensive information about film and TV credits, thereby preserving the factual historical record by accurately reflecting what is listed on-screen.