The Master of Holles Street Hospital, Dr Declan Keane, said yesterday there would be "very critical meetings" in the next week or so to address the midwife crisis.
If these meetings did not resolve the crisis, quotas might be introduced on the number of births that could take place in Dublin hospitals.
He cast doubt on measures suggested by the Eastern Regional Health Authority to resolve the difficulties.
The ERHA said it was taking measures to ensure no Dublin mother would have to go to a hospital outside the city to have her baby.
The continuing loss of midwives leaving the Dublin hospitals to take up public health nurse posts or to work in areas with a lower cost of living outside the capital has led to more than 100 vacancies in Dublin.
Midwives are paid on a scale ranging from £16,961 to £24,765 while the public health nurse scale ranges from £25,663 to £30,538.
On some occasions last month, the National Maternity Hospital in Holles Street had to send first-time mothers home 48 hours after giving birth. Mothers who had given birth before were sent home after 24 hours.
He said safety standards could not be maintained without such measures.
The Eastern Regional Health Authority said 10 per cent of births were to mothers who were from outside Dublin and who could go to maternity hospitals in their own regions.
About 3,000 births a year are to asylum-seekers, it said.
It said it had suggested to the Dublin maternity hospitals - Holles Street, Coombe Women's Hospital and the Rotunda - that women from outside the region should only be accepted if a consultant in that region had referred them on clinical grounds.
But Dr Keane said this restriction had been in operation for the past 18 months and had not solved the problem.
The ERHA suggested that asylum-seekers should have their babies in hospitals outside Dublin except for those settling in the region.
Dr Keane said enforcing this policy would be difficult. Asylum-seekers wanted to be in Dublin and not down the country.
An article in the current issue of The World of Irish Nursing, published by the Irish Nurses' Organisation, suggests that a loss of professional autonomy is a major reason for midwives leaving the profession.
This occurs because of the increasing involvement by obstetricians in births, partly for fear of being sued if something goes wrong and partly because many mothers with private health insurance expect it.
"They feel their autonomy is gone and there isn't much space for development of their role within the hospital setting", Mary Higgins, chairwoman of the INO's midwives section, is quoted as saying.
pomorain@irish-times.ie