An employer would not have to pay a woman on maternity leave a discretionary bonus if the only condition of eligibility for the bonus was that the employee must be in active employment at the time of payment.
If a discretionary bonus amounted to retrospective payment for time worked over a specific period (such as the past year) during which a woman took maternity leave, the employer must include any part of that period the woman spent on compulsory maternity leave in calculating the bonus.