Overworked and underpaid, the midwifery workforce is facing such a shortage that mums-to-be are struggling to find a midwife.
There are calls for urgent action to improve pay and conditions.
It's a 24-hour-a-day, seven-day-a-week job, that self-employed midwife Nadia Pendigrast from Auckland Maternity Care loves.
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But demand is so high she's already fully booked until October.
"We are declining women every day, we get maybe 10/15 texts calls every day," Ms Pendigrast told Newshub.
"So my phone would ring probably every half an hour to hour with another text or with somebody wanting a midwife."
She has been constantly forced to turn mums-to-be away and said it's heartbreaking.
"It's sad, women are doing the right thing, they're calling really early, it's just we book out really fast."
Spokeswoman for midwives' union MERAS, Caroline Conroy, said the shortage of self-employed midwives is now impacting on midwives employed in DHBs.
"Because of the slowness of governments to improve the pay for self-employed midwives, a number of them have left or retired," she said.
And she said it's increasing the workload for hospital midwives.
"Often midwives will go without meal breaks, they will stay on longer after shifts to help their colleagues into the next shift, they will come in early, they will work extra shifts."
Health Minister Dr David Clark admitted the pressure was high.
"There is a global midwife shortage and that creates challenges for New Zealand. But I expect the DHBs to manage any workforce pressures," he said.
The union said retention is crucial.
"We've had in recent weeks a number of midwives going to Australia for jobs there because it's better pay. We do need to something or else the situation's going to get worse," Ms Conroy said.
MERAS said while some DHBs have stepped up, overall there needs to be an improvement in funding and staffing for maternity so mums-to-be continue to get the best care.
MERAS is currently in pay negotiations with the DHBs and wants to achieve improved pay rates for midwives to encourage retention of midwives in New Zealand. The New Zealand of College of Midwives is in discussions with the Ministry of Health to achieve improved pay and conditions for self-employed midwives.