Published: 07 November 2019
A new treatment for pregnant women at high risk of preterm birth can prevent both very preterm birth and death of babies, a clinical trial supported by the NIHR has found.
The Multicentre Randomised Controlled Trial of Transabdominal Versus Transvaginal Cervical Cerclage (MAVRIC) study found that pregnant women who received a treatment called abdominal stitch instead of the traditional vaginal stitch were less likely to give birth before 32 weeks of pregnancy and more likely to give birth to a baby that survived.
The MAVRIC study was a 10-year, UK-wide randomised controlled trial in very high risk women with recurrent pregnancy loss and failed treatment. Over 100 women took part in the study.
The study, published in The American Journal of Obstetrics and Gynecology, found that rates of preterm birth at less than 32 weeks were significantly lower in women who received abdominal stitching than in those who received vaginal stitching (8%v 38%).
This research was supported by the NIHR Guy's and St Thomas' Biomedical Research Centre and the NIHR Applied Research Collaboration (ARC) South London.
One in eight pregnancies end in miscarriage in women who know they are pregnant, and many more happening before a woman is even aware she has become pregnant.
Women who have had premature labour in a previous pregnancy, a miscarriage, surgery, or trauma to the cervix may be at risk of a condition called cervical insufficiency, where the cervix widens and shortens during pregnancy. In pregnancy, the cervix helps keep the baby in the womb, as well as protect the womb – and the baby – from infection.
An opening cervix may lead to premature birth or miscarriage. To counteract an opening cervix, ‘stitches’ are often inserted in a process known as a cervical cerclage.
The stitch can be done in two ways: either through the abdomen or the vagina. Mostly the vaginal route is used because it is less invasive and no major operations. However, some women still miscarry or have early deliveries even though they have had a vaginal stitch put in.
The MAVRIC study was the first randomised clinical trial - a type of clinical trial where people are put into groups at random whereby one of these groups is given the treatment being tested, while the other is the 'control' group - to test abdominal stitch in this group of women.
Professor Andrew Shennan, clinical director of Tommy’s Preterm Surveillance Clinic at Guy’s and St Thomas’, commented: "We are delighted to show that women who lose multiple babies, even after failed stitches will usually have successful pregnancies with an abdominal stitch."
One patient, Susan Harper-Clarke, 41, has a weak cervix and suffered two late miscarriages in 2010 and 2011. Early into her third pregnancy, she enrolled onto the MAVRIC trial at St Thomas’ Hospital and was randomly selected to have the abdominal stitch. Susan stated: “Although it was a major operation, I knew that I was in safe hands and that it was likely to be the only way I was going to have a healthy baby.”
An abdominal stitch leads to the need for a c-section during birth, because the procedure means that women are unable to have a natural vaginal birth. Therefore, it is important that the treatment is used in high risk women who have had previous vaginal stitch that has failed.
Jane Brewin, Chief Executive of Tommy’s, said: “Recurrent pregnancy loss devastates people’s lives; the results of this study give hope to many families. This effective treatment now needs to be available across the NHS; saving lives, reducing preterm birth and the lifetime consequences for those affected.”