If you are a new applicant and not in Singapore, the medical examination can either be done in your home country/place or in Singapore by a qualified doctor. However, the medical examination required for subsequent renewal of the Student's Pass must be done in Singapore. The doctor must record and certify the results of the medical examination in the designated medical report form. The medical report should not be issued more than three months from the submission date of your application or renewal. If a medical report was submitted to ICA or MOM not more than two years from your submission date, there is no need to re-submit a fresh medical report. (The above requirement is not applicable to applicants who are below 15 years old.)

This information is sourced from ICA