Age, wealth and race cause swings in caesarean rates

By MARTIN JOHNSTON

There are huge regional differences in the rate of caesarean births, according to new statistics.

Those differences are said to be partly explained by variations in the age, income and ethnicity of mothers.

The Health Ministry figures for 2002, published yesterday, show that Northland had the lowest caesarean rate, at 15.8 per cent of hospital births, and Southland the highest, at 28 per cent.

The national average was 22.7 per cent - 12,053 of the 53,037 hospital births. This was up slightly from the year before, reflecting a steady increase from 11.7 per cent in 1988.

The Health Ministry remains concerned about the increasing rate, but admits it has no target and questions the World Health Organisation's preference for a maximum 15 per cent.

"Our main aim is ensuring it's as low as it can be and that the discrepancies between areas which are not fully explained by demographics and other issues are reduced," said the ministry's chief adviser for child and youth health, Dr Pat Tuohy.

"We are working with the sector to ensure the caesarean section rate comes out to the lowest level consistent with good practice."

He linked the national increase partly to the long-term trend for women to delay child-birth and the associated increased risk of birth complications. "Younger women tend to have babies the normal way," he said.

The average age of mothers also has an ethnic link: the commonest age-group for Maori women to give birth is 20-24 years; for Pakeha it is 30-34. Maori women are the least likely to have a caesarean and Asians the most likely.

The report notes that while the proportion of women under 19 giving birth has declined, this results from an increasing abortion rate rather than from declining fertility.

Dr Tuohy also linked the regional differences partly to age - plus socio-economic status and ethnicity.

People served by the Counties Manukau, Lakes and Northland District Health Boards were poorer and had lower rates than Canterbury.

Dr Tuohy said women in permanent, higher-income jobs were more inclined to delay child-bearing.

In a bid to halt the caesarean rate rise, clinical guidelines on pregnancy complications had been developed and others, on the best care in labour, were in preparation, he said.

The ministry had also clarified to health boards that they could spend taxpayers' money on caesareans, which cost $4000 to $5000, only if required for the health of the mother or baby. There was no evidence boards were flouting this.

Dr Alastair Haslam, the outgoing New Zealand branch chairman of the Australasian obstetricians and gynaecologists college, said most caesareans had some sort of medical need.

"One person's medical need might not be another person's medical need," he said. "They might have had a bad experience and not want to run the risk of repeating that."

Dr Sue Belgrave, the Waitemata health board's clinical director of obstetrics, said a common reason for elective caesareans was the woman's request in light of a slight risk of harm to the baby from an attempted labour because of a previous caesarean scar.

But they were done only rarely in the complete absence of clinical need - she had only ever done one and would not again.

"There are many obstetricians who feel that if the woman feels strongly about that, that's her choice."

Caesarean births

Rates in 2002 (percentage of all hospital births, by health board)

Northland 15.8.

Lakes (Rotorua-Taupo) 17.8.

Counties Manukau 19.

Capital and Coast (Wellington) 22.

Waitemata 24.2.

Auckland 24.5.

Canterbury 26.5.

National average 22.7 per cent.