Does use of a cervical pessary in pregnancy for individuals with a short cervix safely reduce the risk of preterm birth?
The use of a cervical pessary in pregnancy beginning in the second trimester did not reduce the incidence of preterm birth for pregnant patients with a cervical length of 20 mm or less and no history of preterm birth. Cervical length was measured by transvaginal ultrasonography between 16 0/7 and 23 6/7 weeks' gestation. Pessary was associated with a statistically significant increase in the risk of fetal or neonatal death.
Plan de l'etude:
Randomized controlled trial (nonblinded)
In this unmasked randomized controlled trial, cervical pessary (n = 280) was compared with no cervical pessary (n = 264) for pregnant patients with singleton gestation, cervical length of 20 mm or less, and no history of preterm birth. Patients were enrolled at between 16 0/7 and 23 6/7 weeks' gestation. Cervical length was measured by trained ultrasound technologists as routine screening. Exclusion criteria included history of prior spontaneous preterm birth, cervical dilatation of 3 cm or more, prolapsed amniotic membranes, premature rupture of membranes, evidence of preterm labor, major fetal anomalies, planned cerclage, or conditions likely to indicate medical need for preterm birth. Nearly all patients received vaginal progesterone (98.9%). All personnel for the study, including those placing pessaries, were specifically trained and certified for their role. The study was planned for a sample size of 850 with complete data for 511 participants. The trial was terminated early by the data and safety monitoring board because of a statistically significant increase in fetal or neonatal deaths (pessary: 36/275 [13.1%] vs no pessary: 18/263 [6.8%]; relative risk [RR] 191; 95% CI 1.11 - 3.29; P = .02; number needed to treat to harm = 16; 9 - 84). There was no benefit in reducing the incidence of preterm birth (127/279 [45.5%] vs 120/263 [45.6%]; NS).
Linda Speer, MD
Professor and Chair, Department of Family Medicine
University of Toledo