Misdiagnoses of early miscarriage may be leading doctors to inadvertently terminate healthy pregnancies, ultrasound experts have warned.
Many women have a miscarriage then a curette, a medical procedure to remove the remains of the pregnancy.
But emerging research indicates that as many as one in 200 pregnancies thought to have miscarried might have been viable.
An associate professor in obstetrics and gynaecology at the University of Sydney, George Condous, said more conservative guidelines might be needed to ensure women were not aborting a foetus by mistake.
''We were potentially terminating pregnancies that were wanted," said Professor Condous, who is also the director of Omni Ultrasound, a gynaecological and obstetrics clinic.
The issue is dividing the medical community, with the Royal Australian and New Zealand College of Obstetricians and Gynaecologists denying women are being wrongly diagnosed as having had an early miscarriage.
First-trimester miscarriage is diagnosed using ultrasound measurements of the foetal sac, embryo size and whether a foetal heartbeat can be heard.
In a letter in the Australian and New Zealand Journal of Obstetrics and Gynaecology this month, Professor Condous said individual clinicians' measurements could vary, leaving them to misjudge whether the foetus was properly developed. "Not necessarily everyone who does the scans is very experienced," he said.
He is seeking ethical approval for a study to see if the guidelines for the size of the foetal sac should be increased again from 25 millimetres to 30, and for the embryo from seven to 10 millimetres.
Even smaller measurements used before the guidelines were changed in November last year (20 millimetres and 6 millimetres) were linked to wrongly diagnosed miscarriage for one in 200 pregnancies of uncertain viability, according to British research.
About a quarter of all pregnancies end in miscarriage and Professor Condous said it was just as devastating for a woman to lose her baby in early pregnancy. "The medical community underplays early losses, and we need to be treating them with the same rigour," he said.
Philippa Ramsay, the director of Ultrasound Care, a women's ultrasound practice, said women
often did not want to wait for more scans to double-check the miscarriage diagnosis.
"It's a typical issue we deal with. We have a lot of people who want a really early diagnosis," she said. "Ultrasound is a little window that shows you what's going on in there, so everyone has high expectations."
Dr Ramsay said there could be huge differences in the way clinicians read ultrasounds. "The skill of the operator really varies between practices that concentrate entirely on obstetrics and practices where they scan all sorts of body parts," she said.
Before ultrasound, women just waited. "But now we are trying to give them a diagnosis before their body has miscarried," she said. "It's a bit tricky."
Dr Ramsay said in Australia ultrasounds were usually assessed by two qualified practitioners, unlike in Britain, although she often advised women to wait for a second scan before having a curette.
But the president of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, Michael Permezel, said it would be wrong to make women think their miscarriage could have been wrongly diagnosed. "It's certainly very wrong for them to be alarmed that under the new criteria there would be any risk at all [of false diagnosis]."
He said if there had been any wrongly diagnosed miscarriages in Australia they would be a tiny proportion. How women dealt with miscarriage should be decided individually. Some wanted it out of the way and some did not want to wait for a few weeks for the miscarriage.
- Sydney Morning Herald
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