NEW YORK (Reuters Health) – Among women with a singleton pregnancy, prior preterm birth, and a short cervix, cerclage significantly reduces the risk of another preterm delivery, as well as perinatal mortality and morbidity, a new meta-analysis shows.
“The benefit of cerclage in this selected population is clear,” the research team says. “These results, consistent in five different trials, offer level 1 evidence for benefit from cerclage in a selected population of women at high risk.”
Dr. Vincenzo Berghella of Jefferson Medical College of Thomas Jefferson University in Philadelphia and colleagues report their findings in the March issue of Obstetrics & Gynecology.
They note that in early randomized trials, ultrasound-indicated cerclage for short cervical length yielded contradictory results — but benefits have been seen in women with singleton pregnancies and previous spontaneous preterm birth.
To look at “the totality of the data,” the team identified five randomized trials of cerclage in women with short cervical length on second-trimester transvaginal ultrasonography.
Among women with previous spontaneous preterm birth and singleton gestation, with cervical length less than 25 mm before 24 weeks gestation, the rate of birth before 35 weeks was 28.4% after cerclage compared with 41.3% without cerclage (relative risk 0.70).
In addition, the relative risk of the composite outcome of perinatal mortality and morbidity was 15.6% versus 24.8% with and without cerclage, respectively (RR 0.64).
The research team included some screening recommendations, based on data from the largest trial. For women with a previous spontaneous preterm delivery carrying a single fetus, “screening should start at approximately 16 weeks and continue every 2 weeks until 23 6/7 weeks, unless the cervical length is 25-29 mm, in which case weekly screening is performed,” the authors write. “If cervical length less than 25 mm develops, then the risks and benefits of cerclage should be discussed.”
Obstet Gynecol 2011;117:663-671.0