Dr Boylan said the guidance should be examined from both a clinical and financial perspective.
"It needs to be looked at because from her point of view and the State's point of view this is going to result in more litigation because there will be more adverse outcomes, inevitably," he said.
His concerns are informed in part by the findings of the Ockenden report in the UK, which investigated serious failings in maternity services. The inquiry found that more than 500 mothers and babies experienced avoidable harm or died, identifying failures in foetal monitoring and concluding that existing oversight systems were no longer fit for purpose.
"We don't want to import into Ireland the disastrous approaches that have resulted in so much suffering in the UK," Dr Boylan said.
At the centre of his concerns is the guidance that defines established labour as beginning at 4cm cervical dilation. He believes this creates uncertainty for expectant mothers and could delay assessment and treatment.
"The guidelines are silent on how a woman is supposed to know at home that her cervix has reached 4cm and that makes no sense whatsoever," he said.
He also questioned recommendations that routine foetal heart monitoring should not begin until labour is considered established.
"The guidelines say you don't need to start monitoring the baby's heartbeat until the woman is in the first stage of labour, which they say starts from 4cm. That has associated risks because you are not listening to the baby's heartbeat," he said.
Ireland's National Maternity Strategy, introduced in 2016, was designed to standardise maternity care across the country. Clinical guidelines are developed by the National Women and Infants Health Programme in partnership with the Institute of Obstetricians and Gynaecologists and are regularly updated.
However, Dr Boylan believes aspects of the latest guidance should now be reconsidered.
He is particularly critical of the continued use of the term "latent labour", arguing that it suggests women are not truly in labour until they reach 4cm dilation.
"In other words, a woman can be at home unmonitored, the baby unmonitored and her wondering, 'When should I go in? How do I know when I am 4cm?'"
Dr Boylan traced the concept back to the work of New York obstetrician Emmanuel Friedman in the 1950s, whose observations showed that many women took 12 hours or longer to reach 4cm before labour accelerated.
While the concept became embedded in maternity care, Dr Boylan said subsequent research has demonstrated that relying on it can be harmful.
"We can see that from the report in the United Kingdom, where babies have suffered, babies have died and women have suffered," he said.
Drawing on decades of experience delivering babies and reviewing maternity cases, he said women are still being told they are not in labour despite experiencing painful contractions, simply because they have not reached 4cm dilation.
"That is just not acceptable," he said.
He also said that, through his work reviewing coroner's inquests and medical negligence cases, he is increasingly seeing the concept of latent labour emerge as a factor in serious maternity incidents.
"I am seeing that creeping in now and it needs to be revised and reviewed," he said.
