Hundreds of pregnant mothers in Britain have been given faulty information that prompted them to approve post-miscarriage procedures, in effect aborting healthy babies.

“Around a third of the 500,000 miscarriages a year in the UK are confirmed via ultrasound scans of the fetus and the sac that envelops it in the womb,” reports Fiona MacRae for the British newspaper the Daily Mail. “The scans from very early pregnancies are particularly hard to read and a second scan will often be carried out to ensure accuracy if a miscarriage is suspected.”

However, approval for a second scan often is denied under British national health care. MacRae cited the case of Naila Zubair. She was told she had miscarried and was given drugs to flush out her womb. However, the next day, she was told her baby was still alive. Now, she fears the child may be severely handicapped from the inadvertent abortion attempt.

“Hundreds of mothers-to-be a year are being wrongly told they have lost their baby because of mistakes in reading ultrasound scans, doctors fear,” writes MacRae. “Some of the 400 women given a wrong diagnosis each year will choose to wait to see if they go on to miscarry naturally, but others will take the option of terminating the pregnancy.”

“For most women, sadly there is nothing we can do to prevent a miscarriage,” writes Professor Tom Bourne of the Imperial College of London. “But we do need to make sure we don’t make things worse by intervening unnecessarily in ongoing pregnancies. We hope our work means that the guidelines to determine miscarriage are made as watertight as we would expect for determining death at any other stage of life.”

For instance, he told the Telegraph, if the fetus is very small and a heartbeat can’t be detected, the woman has a second scan seven to ten days later. The same applies if the gestational sac that should contain the fetus is relatively small and appears to be empty. But if the fetus or sac is not unusually small, just one scan is done before the woman is told she has lost her baby.

She then has the option of waiting to miscarry naturally, taking pills to induce the miscarriage or surgical removal, reported MacRae:

But experts say the 2-centimeter cut-off point between having one scan and two is too risky. A study of more than 1,000 British women estimated that around one in 200 who are deemed to have miscarried because they have an apparently empty gestational sac of over 2cm will actually still be pregnant.

These women would benefit from waiting for a second scan a week or so later that would be expected to reveal the fetus was alive.

A further study revealed this figure could be much higher, as the measurements taken from the scans vary by as much as 20 per cent between medical staff.

The researchers said the precise numbers are unclear, but writing in the journal Ultrasound In Obstetrics And Gynecology, they estimated that errors could lead to 400 women with healthy pregnancies being wrongly told their baby has died each year.

The research team, from four London hospitals and the Catholic University of Leuven in Belgium, said: ‘These numbers are significant and relate to pregnancies that would be highly likely to reach term.’

Professor Bourne, who led much of the research, called for an immediate interim change in the guidelines, pending further large-scale research.

In the meantime, he recommends those who are anxious to consider requesting the option of returning in a week to have a second scan.

Dr Mark Hamilton, a consultant gynaecologist at Aberdeen Maternity Hospital, said the research reinforced the need for staff to take the greatest care when determining miscarriage, and urged that medical or surgical procedures should be postponed until the outcome of the pregnancy was a ‘certainty’.

The Royal College of Obstetricians & Gynaecologists said a review of its guidelines was already under way and it will take the new findings into account.