In Kiiski v Tampereen kaupunki C-116/06 the ECJ held that an employee who had been granted about 10 months' parental leave (under Finnish law), and then discovered that she was pregnant and due to give birth part-way through her parental leave, should have been allowed to end her parental leave early and return to work in order to benefit from paid maternity leave. The relevant collective agreement, which provided that a new pregnancy was not a good reason to change the dates of parental leave once they have been agreed, was contrary to the Equal Treatment Directive (76/207/EEC) and the Pregnant Workers Directive (92/85/EEC).

Although the exact circumstances of this case would not arise under UK law, which only allows parental leave of up to 13 weeks per child, it is possible to envisage a situation in which an employee has arranged parental leave several months in advance, and subsequently discovers she is pregnant and likely to be on maternity leave during part of the period in question. Employers should be aware that they may be required to change (or possibly cancel) the parental leave if the employee so requests.