29 Sep 2016

Researchers hit back at response to birth-risk report

1:54 pm on 29 September 2016

Researchers have come out fighting today over claims made in response to their own contentious new findings about maternity care.

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Photo: 123rf.com

Research published yesterday revealed a lower chance of problems at birth if the lead maternity carer was an obstetrician or GP rather than a midwife.

The findings were based on a retrospective study of more than 240,000 births in this country from 2008 to 2012.

It concluded doctor-led care resulted in a 55 percent lower chance of oxygen deprivation during delivery; a 39 percent lower chance of neonatal encephalopathy, which can result in brain injury; and 48 percent lower odds of a low Apgar score, an indication of an unwell baby at birth.

The College of Midwives said yesterday the report highlighted that "private maternity care is better funded and resourced than the public maternity system".

College chief executive Karen Guilliland said in a statement: "It's important to make clear that this study has reported no difference in mortality (baby or mother) whether the Lead Maternity Carer (LMC) is an obstetrician or midwife."

However, in an email today, a co-author of the study, Diana Sarfati, said this was incorrect.

Professor Diana Sarfati,
Co-Head of Department, Department of Public Health

Professor Diana Sarfati. Photo: University of Otago

"In fact, we found differences of the same magnitude and direction as the morbidity outcome.

"For example, the best estimate from the study for neonatal mortality (the measure most likely to be related to the care received during delivery) is that there is 38 percent lower risk of death with a medical-led LMC compared to a midwife one.

"This finding is not 'statistically significant'. This is absolutely not the same as being 'no difference', and these results are in no way reassuring."

'Absolute numbers ... alarmingly high' - study co-author

Professor Sarfati also said the college claimed the researchers compared autonomous, or independent, midwives with private obstetricians.

"This is not correct. We compared midwife LMCs with any medical LMCs."

The added criticism that the researchers should have used absolute numbers in their study, rather than percentages, and that numbers - had they been used - would be small, was also not correct.

"In fact, we avoided the absolute numbers because they are alarmingly high."

Dismissing earlier study not correct

Professor Sarfati, who is co-head of the department of public health at Otago University in Wellington, also took issue with [http://www.radionz.co.nz/national/programmes/ninetonoon/audio/201817834/study-nz-maternity-system-needs-improvement comments made by Health Ministry head of child and youth health Pat Tuohy, in media interviews about the study findings yesterday.

Dr Tuohy raised an earlier, equally contentious study by Otago University Women's Health Research Centre director Beverley Lawton, showing babies were more likely to die at birth or soon after if the midwife was in their first year on the job.

He told Nine To Noon the Ministry would be referring the new study for expert analysis by the National Maternity Monitoring Group, adding that "the detailed analysis of Bev Lawton's study raised considerable doubts about the validity of that study."

To dismiss the earlier study as flawed and incorrect was also not correct, Professor Sarfati said.

"It has been reviewed by several senior epidemiologists, who rejected the College of Midwives' assessment of this study [as flawed]."

Risk factors controlled

Dr Tuohy also said the new study only looked at who the LMC was at beginning of the maternity care, failing to take account of who was at the delivery.

Professor Sarfati said they removed all of the women from the latest study where such a transfer occurred and the results were unchanged.

"We, as researchers, controlled carefully for demographic and risk factor differences between groups and we are confident that this does not account for our results.

"This is supported by the several national and international experts in research methodology that independently peer reviewed our study."

Two of the five authors of the new study were midwives, Professor Sarfati said.

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