Research points finger at midwives

Bad outcomes for new babies are more likely when a mother’s chosen maternity carer is a midwife, as opposed to a medical specialist, research shows.

The Otago University research project examined major adverse perinatal outcomes of 240,000 babies born between 2008 and 2012.

It found babies were less likely to encounter problems during and after birth, when their mother’s carer was a specialist obstetrician or general practitioner.

The study found ‘‘an unexplained excess of adverse events’’ in midwife-led births compared with medically-led deliveries, where midwives were practising autonomously.

New Zealand College of Midwives chief executive Karen Guilliland said it was not a fair comparison. The study did not say why the babies were unwell.

It did find babies with medical carers had 55 per cent lower odds of oxygen deprivation during the delivery and were 39 per cent less likely to develop a condition called neonatal encephalopathy – which can result in brain injury.

Guilliland said there could be any number of reasons behind the data. Midwives were more likely to look after young women, rural women and sick women.

Those factors alone could result in adverse outcomes during childbirth, she said. ‘‘If we are being compared to an obstetrician then we know that none of those obstetrician clients would be rural, they won’t be [living] three hours away from a hospital.’’

The authors said they assessed the likelihood that distance to hospital could explain the results (or any other unmeasured confounding factor) but found this to be ‘‘exceptionally unlikely’’.

The researchers said New Zealand’s rate of adverse outcomes was low and comparable to other developed countries but their findings suggested some avoidable adverse outcomes were occurring.

They called for further research to better understand why.

Ministry of Health principal maternity adviser Bronwen Pelvin said the findings were unexpected, given international evidence showed a midwifery-led maternity system leads to similar outcomes for women and their babies.

‘‘The findings are being taken seriously and require further investigation,’’ she said.

Pelvin said the study was referred to the National Maternity Monitoring Group for advice.

She said further research could ‘‘help us better understand whether the findings reflect something about the way the study was done, differences in the maternity care provided by midwives and doctors, and whether there are things we can change to get better outcomes for women and their babies’’.

New Zealand adopted a midwife-led model of maternity care in 1990.

Study author Ellie Wernham said, as a former midwife, she was able to identify aspects of the maternity system where improvements were needed.

Her aim was to provide ‘‘better outcomes for babies’’.