Thousands of unborn babies could have been saved if doctors had used a thinner type of thread during cervical stitching on pregnant women, according to a new study.
UK researchers are urging surgeons to reconsider using a particular type of thread for a cervical stitching procedure which aims to prevent premature birth and baby death.
Doctors use two types of sutures when doing the procedure – either a thinner ‘fishing line’ nylon thread or a thicker ‘shoe lace’ braided thread.
Now a new study by Imperial College London has revealed the thinner type to be more effective. It showed babies were three times more likely to be stillborn or miscarried and almost twice as likely to be born prematurely with the thicker thread, compared to the thinner thread.
The team believes, worldwide, more than 172,000 baby deaths and 170,000 premature births could have been prevented if the thicker thread was replaced with the thinner thread.
What is the procedure
The cervical stitch procedure, also called cervical cerclage, involves surgeons placing a stitch into the cervix – to strengthen it and prevent it opening too early in the pregnancy.
The procedure is performed on about two million women globally every year, who have been deemed at high risk of miscarriage or premature birth.
A small amount of women, at risk of premature births, undergo cervical stitching.
The research
The study looked at 671 women who had the procedure at five UK hospitals over the last ten years. Half were treated with the thinner thread, while the other half had the thicker thread.
The results revealed:
A second study monitored 50 women who had the procedure and found that those with the thicker thread had more of the harmful bacteria in the vagina and around the cervix that has have been associated with poor outcomes during pregnancy, like infection in babies and premature birth.
A study has investigated a cause of premature births.
What does it mean?
The researchers are now encouraging doctors to use the thin, nylon thread.
“We strongly advise that the thicker thread – which is currently used in the majority of procedures – only be used in a research setting whilst we thoroughly investigate the risks this may hold,” lead author of the study, Professor Phillip Bennett said.
President of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists Professor Michael Permezel said many clinics in Australia were already using the thinner nylon, believing it to be a superior product.
“A small number of women benefit with suturing to prevent preterm birth. The study has revealed there does appear to be an overall benefit when using the thinner thread,” he said.
“You’ll find a lot of clinics are switching to the nylon, or have already. This evidence would encourage many doctors to at least review their practice.”
But Professor Permezel said the single study wasn’t enough to completely discredit the use of the thicker thread.
The study aims to prevent premature births and baby deaths.
“I wouldn’t say there is no place for braided thread. It needs to be looked at with more studies, but this is still an important piece of evidence,” he said.
“Some clinics have a concern the nylon can cut out more easily and the braided type is less likely to break. But with the braided, there is a higher risk of infection.
“The nylon is more helpful as a whole, but it doesn’t mean there isn’t special circumstances for braided sutures.”
Mr Permezel said sutures only help a small number of pregnant women who have a weak cervix. But the procedure – which has been used since the 1950s – has saved many lives.
“We don’t know a lot about preventing preterm births, but at least this can be done and can be really effective in woman where a weak cervix is the cause,” he said. “At least tens of thousands of babies have been saved because of this procedure.”
What’s next?
Professor Phillip Bennett from the Department of Surgery and Cancer at Imperial College London said a larger study was now being carried out on 900 patients by University of Birmingham.
“Our current study suggests the thick multifilament thread is associated with increased risk of complications. Even after factoring in the age and overall health of the patient,” he said.
“However there are other factors that may influence the risks, such as surgical technique. Only by performing a large clinical trial can we confirm whether the thicker thread itself is triggering complications.”
Anyone concerned about the cervical stitch procedure should speak to their healthcare team.