THE rate of caesarean section among mothers with private health insurance is far higher than among those who rely on public care.
A new ESRI report today raises the possibility that doctors treat their fee-paying patients differently to mothers who rely on public care.
It shows that 35pc of women with private health insurance give birth by caesarean section and that 60pc of these procedures are planned.
This contrasts with a caesarean section rate of 24pc among women without insurance in the same public hospitals, with 44pc of the operations planned.
The report, which provides a snapshot of trends in public hospitals, said the rate of caesarean section last year was 26pc.
Asked to comment on the difference between public and privately-insurance mothers, Prof Declan Devane, professor of midwifery at NUI Galway, said it raises serious questions.
"It can't be explained by any difference in risk factors between the two groups," he said.
And it also cannot be due to mothers asking for a caesarean section where there are no risk factors to merit the procedure.
"We already know that there are big variations in the rate of this procedure between different units, but now we also know there are differences internally," he added.
Although it is a common procedure, a caesarean section is still major abdominal surgery and, like any operation, it carries a certain amount of risk so hospitals are under pressure to reduce the rate.
The Institute of Obstetricians and Gynaecologists is to issue the first national guidelines shortly to advise doctors on caesarean sections.
The report, which looked at activities in 57 acute public hospitals, also found that while less private patients were treated in public hospitals than public patients, their average stay was longer.
Prof Miriam Wiley of the ESRI said the average length of stay was 4.9 days but it was longer in voluntary hospitals at 5.8 days.
She said patients who were in hospital for more than 30 days accounted for just 3pc of discharges and 32pc of in-patient bed days.
This means that the problem of so-called "bed blockers" remains -- mainly elderly people who cannot be discharged even though they no longer need acute care.
Prof Wiley said it was clear that if appropriate care facilities were found for these patients it would substantially free up the availability of beds.
"It's a small proportion of discharges but a high usage of bed days," she added.
Overall, despite the cuts in budgets, hospitals are treating more patients and there were 1.44 million discharges last year compared to 1.41 million in 2009.
This is partly due to the higher numbers of patients who are treated on a daycare basis, with no need for an overnight bed stay.
Day patients accounted for 53pc of total discharges in 2010, an increase of 4pc since 2009. The figure was 53pc in 2006, showing progress is being made in making hospitals more efficient in this area.