Placement of a pessary to support a short cervix failed to prevent preterm delivery, compared with expectant management, in an international open-label trial reported online March 16 in the New England Journal of Medicine.
Transvaginal placement of a silicone pessary around the cervix “is thought to support the cervix and change its direction toward the sacrum, thereby reducing the direct pressure from the uterine contents on the cervical canal.” However, two recent randomized trials of this treatment produced contradictory results, with one showing the device reducing the rate of spontaneous preterm delivery and the other showing it had no effect, reported Dr. Kypros H. Nicolaides of the Harris Birthright Research Center for Fetal Medicine, King’s College, London, and his colleagues.
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They performed a randomized trial of women aged 16 years and older who had singleton pregnancies and who were found at routine ultrasound examination at 20-24 weeks’ gestation to have a cervical length of 25 mm or less. These study participants – enrolled during a 5-year period at 16 maternity hospitals in England, Slovenia, Portugal, Chile, Australia, Italy, Albania, Germany, and Belgium – were assigned to either placement of a cervical pessary or expectant management and followed every 4 weeks until delivery. The analysis included 465 women in the pessary group and 467 women in the control group.
Women who had a very short cervix (15 mm or less) were also given intravaginal progesterone capsules to use nightly.
The primary outcome measure – spontaneous delivery before 34 weeks’ gestation – occurred in 55 women (12.0%) who received pessaries and 50 (10.8%) in the control group. This outcome remained similar between the two study groups when the data were adjusted to control for treatment center and for the patients’ cervical length, obstetric history, progesterone use, and antibiotic treatment.
Secondary outcomes of perinatal death, adverse neonatal events, and need for special neonatal care also did not differ significantly between women who received a pessary and those who did not, the researchers reported (N Engl J Med. 2016;374:1044-52). Both the primary and secondary outcomes were unchanged in a series of post-hoc subgroup analyses.
Women who received a pessary reported higher rates of new or increased vaginal discharge (46.8% vs. 13.8%) and pelvic discomfort (11.4% vs. 3.4%) during follow-up visits. Pessaries were removed before 34 weeks’ in 114 women (24.5%), usually due to iatrogenic delivery, preterm labor, or premature rupture of the membranes. But 47 women requested pessary removal because of discomfort, vaginal discharge, or vaginal bleeding.
This study was supported by the Fetal Medicine Foundation. Dr. Nicolaides and his colleagues reported having no relevant financial disclosures.