More than 1100 DHB-employed midwives have voted overwhelmingly to reject the DHBs' pay offer and go on strike.
Eighty per cent of midwives' union MERAS members employed by all 20 DHBs cast their votes.
Of these, 90 per cent voted to reject the DHBs' offer and to take strike action.
Midwives will be giving notice from tomorrow of two-hour work stoppages every day on every shift over a two-week period - effective November 22 to December 5.
MERAS industrial co-leader Jill Ovens said they wanted to maximise disruption for the DHBs while minimising the effect on women and their babies. The strike comes after a year of negotiations.
Members have rejected the pay offer from the DHBs because they were refusing to recognise midwives' skills and responsibilities by offering them the same pay scale as nurses, she said.
The union wanted a further percentage to recognise the difference and a retention allowance to address the pressing midwifery shortage.
"They [midwives] have a high level of responsibility, study for a four-year direct-entry degree, and their scope of practice includes a high level of clinical decision-making," Owens said.
"The DHBs and Ministry of Health know urgent action is needed to address the midwifery shortage and midwives' work-related stress."
National Representatives Council chair Kelly McConville said the vote to strike reflected concerns midwives had about their working conditions and that they are not acknowledged in their scope of practice.
"It shows how we've been working at crisis point for a long time now."
District Health Boards spokesman Jim Green remained positive that mediation would help solve the impasses in pay talks with midwives and prevent the threatened strikes.
He said midwives covered by the union MERAS had been offered the same pay deal as midwives covered by the NZNO.
"The offer they've turned down is 9 per cent over the next 18 months plus two pay step increases and a lump sum payment.
"That's a very good offer and the same as other midwives employed by DHBs."
Green said DHBs would continue trying to settle these negotiations and expected mediation would help find a way forward and prevent industrial action.
"We respect the important role of midwives while also recognising that an excellent offer has already been made. We are keen to talk further with the union."