Section 3 safeguards an employee's entitlement to the extended minimum period of 18 weeks maternity leave where premature births are concerned. Section 5 provides that in the event of the sickness of the employee, an employer may agree to the employee's request to terminate her period of additional maternity leave. Once terminated, the employee shall not be entitled to take the remainder of the additional maternity leave at a later date. Any absence from work due to sickness following the termination of the period of additional maternity leave shall be treated in the same manner as any absence from work of the employee due to sickness.