Single stranded suture threads could prevent pregnancy infection complications, C-STICH trial finds

The trial was the largest of its type and is published in The Lancet. It involved more than 2000 expectant mothers who needed a procedure called a cerclage, where a purse string suture is placed around the neck of the womb (the cervix) during their pregnancy. Women were randomly allocated to have the surgical procedure performed using either a single stranded thread or a braided thread.

Researchers tested whether there would be any difference in miscarriage or stillbirth, due to an increased risk of infection, from using a braided suture thread. The research, which is funded by the National Institute For Health and Care Research, the research partner of the NHS, public health and social care, demonstrates that single stranded sutures could potentially improve outcomes for mothers at risk of preterm birth.

The team led by researchers from the University of Birmingham and Birmingham Women's and Children's Hospital found that the mothers treated with single stranded threads had no differences in pregnancy loss or preterm birth but reported fewer instances of infection and sepsis. This could have important implications for the health outcomes of mothers and babies who are treated with a cervical cerclage in their pregnancy.

Dr Vicky Hodgetts-Morton, NIHR Clinical Lecturer in Obstetrics at the University of Birmingham and Birmingham Women's Hospital explained the implications of the trial results. Dr Hodgetts-Morton said:

"Preterm birth is a significant problem, complicating approximately one in ten pregnancies around the world. The consequences of preterm birth may be significant with some babies being born too early to survive, and those that survive are at increased risk of health complications. One cause for preterm birth is cervical insufficiency, occurring in 0.5% to 1% of pregnant women for which the placement of a vaginal cervical cerclage can be an effective treatment."

"Suture thread choice has the potential to improve how well a cerclage works in preventing miscarriage, stillbirth and preterm birth. Both single stranded and braided threads are commonly used to perform cerclages and our findings show no differences in pregnancy loss and preterm birth. The C-STICH trial results did show an increased risk of infections in labour and around the time of delivery with braided threads and this supported our hypothesis that a single stranded thread could reduce the risk of infection developing during the pregnancy."