Midwives believe they've been left with no choice but to take court action over their pay saying they're discriminated against because of their gender.

The College of Midwives is filing a pay parity discrimination case in the High Court tomorrow.  

Their argument is that the midwifery-led system for maternity care has improved things so much for women and their babies that New Zealand is now a world leader.  

Despite this, midwives are paid the equivalent of someone considered to be unskilled, semi-skilled or junior staff.

Chief executive Karen Guilliland said women have had enough.

"Any service in which women is the dominant provider is poorly paid," she said.  

She wants to know why caring professions have so little value attacehed to them.  

"All the care that nurses, midwives, carers and preschool teachers do is far less than the work that's done in the male trades.  Why is that?  Why?," she asked.  

The National Council of Women is also supporting midwives in their decision.

President Rae Duff said sexism in our society causes structural inequality, and women are the victims.

She said at least awareness of pay inequality has increased to the point where it's translating into action.