Up to 400 miscarriage test errors occur in the UK every year, leading to the deaths of too many babies who are aborted, often because doctors are too hasty to diagnose miscarriage rather than carry out a second ultrasound scan, researchers from Imperial College London revealed in Ultrasound in Obstetrics and Gynaecology. More babies die in this way in the UK than from cot deaths (crib deaths), the authors added.

The journal this week reports on four studies carried out at Imperial College London (UK), Queen Mary, University of London (UK), and Katholieke Universiteit Leuven (Belgium).

A considerable number of embryos/fetuses that are destroyed, if given the chance, would have reached full term, the researchers stated.

Senior author, Professor Tom Bourne, said that the medical profession has the responsibility of putting its house in order.

Approximately half a million pregnant women have a miscarriage annually in the UK. Typically, a doctor carries out an ultrasound scan to measure the gestational sac size. If no heartbeat is detected, or if the sac appears to be empty, the doctor diagnoses a miscarriage.

If the doctor is not 100% sure he/she should measure the gestational sac again with seven to ten days to either confirm a miscarriage or rule it out.

Tragically, according to this latest study that looked into 1,000 miscarriage diagnoses, the error rate is so high that a significant number of perfectly viable babies are being destroyed.

The authors believe up to 400 viable pregnancies are being diagnosed mistakenly as miscarriages annually – that is 100 more than the number of cot deaths in the country each year.

A follow-up scan should be carried out ten days after the first scan “in all cases”, Professor Borne said.

Ruth Bender Atik, of the Miscarriage Association, a UK charity, said:

“Most women who have bleeding or pain in pregnancy are very anxious to find out if all is well or if they are miscarrying. They usually expect an ultrasound scan to provide a definite answer, but this research shows how crucial it is to repeat the scan if there is any possibility of error. It can be a very anxious wait but it will ensure that mistakes aren’t made.”

The Miscarriage Association says that although waiting for a repeat scan might mean a long period of uncertainty and worry for the mother, it will reduce to a minimum the chances of harming a viable pregnancy.

Barbara Hepworth-Jones, a Trustee of the Miscarriage Association, and who has had several miscarriages, is quoted in the charity’s website as saying:

“In one of my pregnancies I was told that a heartbeat should be seen by now and it looked as if I was miscarrying – but a week later the scan showed that the sac had grown and there was a heartbeat. That waiting is so difficult, when you prepare yourself for the worst. It also made my last two miscarriages very prolonged, as I had to have a third scan just to be absolutely sure. But at least I am certain didn’t lose a viable pregnancy.”

Professor Bourne said:

“By identifying this problem we hope that guidelines will be reviewed so that inadvertent termination of wanted pregnancies cannot happen. We also hope backing will be given to even larger studies to test new guidelines prospectively,” says Bourne. “Currently there is a risk that some women seeking reassurance with pain or bleeding in early pregnancy may be told they have had a miscarriage, and choose to undergo surgical or medical treatment when the pregnancy is in fact healthy.”

Another study published in the same journal revealed that different clinicians can measure the gestational sac of one pregnancy with a variation of 20% in size. If the first measurement over-estimated the sac size while the second did the opposite, there is a greater risk that the second clinician will conclude that no growth had occurred.

Co-author, Dr. Anne Pexsters of the Katholieke Universiteit Leuven, Belgium, said:

“These errors could lead to a false diagnosis of miscarriage
being made in some women.”

Co-author, Professor Dirk Timmerman from Katholieke Universiteit Leuven, explained that several experts in clinical practice have long been concerned about the scale of miscarriage diagnosis errors.

Prof. Timmerman said:

“We are pleased that our data have identified where these errors might occur so that we can prevent mistakes happening in the future.”

Written by Christian Nordqvist