A new study from Imperial College London finds that a common surgical procedure, known as cervical cerclage, aimed at preventing premature births actually increases the likelihood that a baby will be born prematurely, prompting researchers to call for a change in procedure that they say could prevent an estimated 172,000 deaths worldwide.
For decades, the practice of cervical cerclage has been used as a preventative measure in cases where a women is thought to be at high risk for miscarriage or premature birth.
Performed on approximately two million woman a year, the procedure requires placing a stitch in the women’s cervix to hold it closed and to help control the spread of infection, which can travel through the cervical opening and into the womb. Currently, there are two options for suture material, one is a thicker, braided strand of fibers while the other is a single nylon strand. Up until now, no studies have investigated the efficacy of one material over the other, yet a full 80% of surgeons are known to use the braided strand, with claims that it is less difficult to work with and stronger once put in place.
“Braided suture material is commonly used in preference to monofilament for cervical cerclage because it is assumed that braided suture provides a more secure cerclage that is less likely to slip or tear the cervix,” say the study’s authors, whose findings appear in the journal Science Translational Medicine. “However, this assumption is not evidence-based.”
The study involved 671 women who underwent cerclage at one of five hospitals in the UK over the last ten years, with results showing a threefold increase in rate of intrauterine death (15 per cent compared to five per cent) in cases where the thicker thread was used as opposed to the single strand. Researchers also found that the braided thread was associated with preterm births in 28 per cent of cases in comparison to only 17 per cent of the time with the single thread.
Researchers speculate that the braided thread causes a buildup of harmful bacteria in the birth canal and around the cervix, an assumption backed by a smaller randomized trial they conducted involving 49 women who received cervical cerclage. Of those whose procedure involved a braided suture 37 per cent were found to have increased foreign bacteria in their vaginas in comparison to no increases for those whose procedures involved the single strand.
The new findings could entail a shift in practice which researchers believe could save thousands of lives. “We estimate that a global shift to monofilament suture use for cervical cerclage would prevent 170,000 pre-term births and 172,000 fetal losses per annum worldwide,” say the study’s authors.
Premature birth is currently the number one cause of child-related mortality in the developed world. A number of factors are known to contribute to its occurrence, including intrauterine infection, fetal development and pregnancy history.
Recently, a team of researchers led by University of Calgary’s Suzanne Tough came up with a blood test that helps to identify pregnancies at risk of preterm birth before 40 weeks of gestation. Looking at genetic profiles and bioinformatics for approximately 3,300 pregnant women, the team was able to uncover common markers that were consistently associated with premature birth.
“Identifying those women who are at risk of premature birth, as early as 17 weeks in their pregnancy, will help clinicians personalize approaches to prevent preterm birth,” says Tough, professor in the Departments of Paediatrics and Community Health Sciences at the Cumming School of Medicine in Calgary.