About 10 per cent of community midwives have walked from the job since the vaccine mandate was introduced, forcing DHBs to hire locums to fill the gaps in the hardest hit areas such as Thames and Taranaki.
The Ministry of Health has confirmed 164 out of 1583 LMCs across the country have refused to provide them with their vaccination statuses since November 15 when midwives were required to have had their first dose.
The MoH is refusing to provide the Herald with the breakdown by district citing privacy.
But, according to the New Zealand College of Midwives, there's an uneven distribution across the country of lead maternity carers who won't get vaccinated.
Thames is one of those hardest hit areas, the Waikato DHB has confirmed to the Herald.
The Waikato DHB has had to bring in four LMC locums in Thames and find cover for two DHB-employed midwives who have been stood down from the Thames Birthing Unit since vaccines were mandated three weeks ago.
Of the midwives employed by the countries DHB, 46 have been stood down including 10 in Waikato and 10 in Counties Manukau as of November 22.
A Waikato DHB spokesperson said the DHB had put plans in place ahead of the mandate to accept LMC referrals if they were unable to find a replacement LMC. This had meant the Thames Birthing Centre would be caring for eight women per month compared to the usual five.
Coromandel MP Scott Simpson said the Thames Coromandel area was short of midwives at the best of times so even a small number exiting the service would create further strain on women needing them.
The New Zealand College of Midwives chief executive Alison Eddy said the college runs a national midwifery locum service with its sister organisation Midwifery and Maternity Provider Organisation and had been sending locums to Thames and the Bay of Plenty.
The most impacted areas included Thames and Taranaki where groups of midwives seemed to have left, she said.
In other areas only a small number had left so the workload was more easily absorbed or in places such as Tauranga there was a good supply of midwives who could pick up those departed midwives' clients.
Eddy believed it was only a "short-term issue" as going forward women who were only just pregnant would be accessing midwives who would be practising long-term. It had also coincided with summer when a lot of LMCs took breaks.
Eddy's expectations were that before the midwife left due to the mandate they would have made plans to transfer the care to a colleague.
"It's not an easy environment for some anyway. So some of that might have fed into this decision to leave at this point because of the mandate. There's multiple reasons I think that we are seeing this happening."
Many midwives have been feeling under-resourced, under-supported and overworked for some time.
In the other hard hit area - Taranaki - the DHB had stood down three midwives and eight LMCs had handed over their caseloads to the DHB or other LMCs.
Taranaki DHB's chief operating officer Gillian Campbell said health leaders and community providers were working together to make sure they had a continuation of services and some such as midwifery may look a little different.
A MoH spokesperson said the health and wellbeing of pregnant people and their babies was of paramount importance and the overwhelming majority of midwives in New Zealand have been vaccinated.
The figures provided were "a snapshot in time" and there may be reasons other than the mandate as to why they had yet provided evidence of their vaccination status. This included because they may not currently be practising, are overseas or on leave.
The MoH was continuing to work with DHBs and its colleagues in the maternity sector to encourage any midwives who are yet to be vaccinated to do so, the spokesperson said.
It had also increased the Covid-19 locum contract with the New Zealand College of Midwives to enable them to provide locums to the hardest hit areas.
"Maternity care will continue to be provided and primary, secondary and tertiary maternity facilities will remain open during any stage of the Covid-19 pandemic."