Counter: pregnancy and employment law

The ordinance on maternity protection is 23 years old. Yet, according to a study by Unisanté and HESAV (Haute école de santé Vaud), it is hard to apply and respect in French-speaking Switzerland. What rights does a pregnant worker have, for example, if she works in a job where she has to stand all day or carry heavy loads? And what can employers anticipate or put in place to foster a suitable environment for pregnant employees?