Legal Question in Employment Law in California

It depends on the reason for the change. In California, an employer of 5 or more employees may not discriminate against an employee for taking maternity leave. And if you qualify for family leave, the employer is obligated to allow you to return to the same or similar position you had when you went out on leave. But this does not mean the employer cannot reduce the hours for a legitimate business reason. In other words, if they would have reduced your hours anyway, regardless of whether you took leave or not, it is legal.

If you think the employer did not have a legitimate reason for reducing your hours, you should consult with an employment law attorney in your area.