Growing obesity levels among mothers-to-be are driving up caesarean section rates, the Master of the Rotunda hospital has said.

According to Dr Sam Coulter-Smith, obesity in pregnant women is contributing to an increase in the number of C-sections being carried out.

The delivery method has reached record levels in the Rotunda and Dublin's two other main maternity hospitals.

Dr Coulter-Smith explained that a dramatic change in lifestyles over the past generation had lead to increasingly overweight women giving birth.

This in turn led to bigger babies, which are more likely to require C-section delivery.

Diabetes

"There is a greater tendency towards diabetic situations, and the higher the mother's blood sugar is, the higher the baby's blood sugar will be," he told the Herald.

"That triggers a cascade effect which causes the baby's growth to increase, and that leads to bigger babies. Over the last 30 years, the average weight of babies has increased.

"When I came back from the UK in 1996, we did a diabetes clinic and we used to see a handful of people, maybe seven or eight a week. Now that would be more like 100."

Dr Coulter-Smith said one factor was larger numbers of people of different races who might have a higher pre-disposition to diabetes.

But he said the biggest factor was the indigenous population not getting enough exercise, eating takeaways and drinking fizzy drinks.

He recommended that women maintained a good, balanced diet through pregnancy.

Last year, 26pc of deliveries in the Rotunda were by C-section, compared to 24pc in the Coombe and 19pc in Holles Street. However, the levels as a proportion of overall births at the Rotunda are falling.

Dr Coulter-Smith said obesity was just one explanation for the rise in the numbers of caesarean sections.

Another upward trend is the number of multiple births as a result of fertility treatment, which are more likely to be carried out by C-section. The Rotunda's own expertise in fertility treatment has given it a larger percentage of multiple births.

The figures do not show how many C-sections are for emergency reasons and how many are elective.

Dr Coulter-Smith dismissed of the term "too posh to push".

"A lot of women might have had traumatic first deliveries and had such a tough time, they might request a caesarean section for their second", he said.

He added: "It would be wrong to say we should have a target caesarean section rate", he said. "But we should understand why the rate is what it is. You have to take each case individually and decide what is right for that person", he added.

aphelan@herald.ie

- Andrew Phelan