A total of 22 babies were born in the space of just 12 hours, according to the stats from one of the country's busiest maternity hospitals.
However, Master Dr Sam Coulter-Smith said that this level of activity is "unsustainable" due to the physical limitations of the outdated building.
At another point in 2012, the hospital had 42 deliveries in the space of 24 hours, Dr Coulter-Smith told a service in St Patrick's Cathedral.
Dr Coulter-Smith said that investment in Irish maternity services was below that of other countries, and that this was contributing to "an overload and overcrowding in hospitals".
"That level of activity is simply unsustainable when patient safety and quality of healthcare must be paramount," he said of the oldest working maternity hospital in the world.
Dr Coulter-Smith said that he supports the suggestion to co-locate the Rotunda with the Mater Hospital..
He said that in the past four years, the links between the two hospitals have "deepened and multiplied".
"For example, we now share 18 joint consultant appointments -- over 30,000 hours a year of shared specialist time," he said.
"These inter-institutional and inter-disciplinary links allow us to continue to offer the kind of care our mothers and babies need and deserve."
And he said that many women face attending the hospital for pregnancy care which should be provided in the community.
"The Rotunda's emergency room handles 25,000 women with pregnancy complications every year. That's busier than many casualty departments around the country," he said.
"We look after about 10,500 maternity patient s a year.
"We've just completed two of the busiest years in the history of the hospital with record numbers of deliveries in 2011."
The Master said that the medical care staff in Ireland are working in more and more restricted conditions.
"Today, our doctors, nurses and midwives are undervalued, under-resourced, and are being asked to work from institutions which are not fit for purpose," he said. "If we're not careful, we will lose our most valuable assets.
"We spend large amounts of money teaching and training our medical and nursing graduates, only to lose them to distant shores and other health services."