Despite years of equality, women who leave their jobs to have children still face a tough career progression, say unions.

Helen Kelly, president of the Council of Trade Unions, said it was difficult for women to maintain an equal foothold in the workplace, particularly after having a baby.

"Many women who return to work return to jobs where they are overqualified, or at a lower level of pay."

Ms Kelly said one of the issues for women was the lack of provision for out-of-school care support.

Flexible hours were good if children were school-age, she said, but did not help if they were younger or during school holidays.

"Flexible working conditions help people stay at work, but women still do lose career opportunities and positions. A lot of jobs are hard to make flexible too."

Suzanne McNabb, the national women's officer for the Tertiary Education Union, co-ordinated a 2007 report on women returning to work.

She said there were issues for women both when pregnant and returning to work.

Employers and Manufacturers Association employment services manager David Lowe says employers have made giant leaps in working with women who leave to start a family.

But he admits that anyone who takes extended leave from a business poses difficulties for their bosses.