My wife has been asked to resign during her pregnancy

Resignation on the grounds of Pregnancy would tantamount to sheer contradiction of the Fundamental Rights laid down under Constitution. However, it would still be pertinent to refer to the contractual terms of employment which may have been laid down either in the appointment letter or in any agreement signed between your Wife and the Employer upon appointment. One can even challenge the contractual terms. However, the first step to be taken is sending of a legal notice against such action taken by the Employer.