In order to benefit from the pregnancy and maternity protection provided for in articles L. 1225-1 et seq., the employee shall submit to her employer, against receipt or by registered letter with acknowledgement of receipt, a medical certificate attesting to her state of pregnancy and the presumed date of delivery or the actual date of delivery, as well as, where applicable, the existence and foreseeable duration of her medical condition requiring an extension of the period of suspension of her employment contract.