Cervical pessary fails to lower preterm birth risk due to short cervix

Key takeaways:

• Preterm delivery or neonatal death occurred in 45.5% of the pessary group vs. 45.6% of the usual care group.
• Fetal or neonatal death rates were 13.3% in the pessary group vs. 6.8% in the usual care group.

Use of a cervical pessary not only did not prevent preterm birth for women with a short cervix, but was associated with higher fetal or neonatal mortality rate, researchers reported in JAMA.

Cervical pessary placement has been studied to prevent preterm birth among women with singleton pregnancies and short cervixes. Previous trials demonstrated differences in cervical pessary effects with some showing lower preterm birth rates and some showing no benefit, according to study background.

“The randomized Trial of Pessary in Singleton Pregnancies With a Short Cervix (TOPS) was performed to test the hypothesis that nonlaboring individuals carrying a singleton gestation, with no prior preterm birth history and a cervical length of 20 mm or less prior to 24 weeks of gestation, would have a lower rate of preterm birth or fetal death before 37 weeks of gestation with placement of a cervical pessary,” Matthew K. Hoffman, MD, MPH, endowed chair in the department of obstetrics and gynecology at Christiana Care Health Services in Newark, Delaware, and colleagues wrote.

Of a planned sample of 850 participants, Hoffman and colleagues enrolled 544 women (mean age, 29.5 years) with a singleton pregnancy who were not in labor and who had a transvaginal ultrasound-determined cervical length of 20 mm or less at 16 through 23 weeks gestation from February 2017 to Nov. 5 2021, at 12 U.S. centers. Researchers randomly assigned participants to a cervical pessary placed by a trained clinician (n = 280) or usual care (n = 264).

The primary outcome was delivery or fetal death prior to 37 weeks gestation.

Study recruitment was halted due to concern for fetal or neonatal mortality and futility.

Overall, 98.9% of women received vaginal progesterone during the study period. A total of 45.5% of women who received cervical pessary placement and 45.6% of women who received usual care experienced preterm birth or fetal or neonatal mortality (RR = 1; 95% CI, 0.83-1.2).

Preterm delivery before 37 weeks gestation occurred among 39.1% of women who received cervical pessary placement and 42.2% of women who received usual care. Fetal or neonatal mortality occurred among 13.3% of women who received cervical pessary placement and 6.8% of women who received usual care (RR = 1.94; 95% CI, 1.13-3.32).

“This trial raises a new concern, given the higher rate of fetal or neonatal/infant death among individuals who received a pessary; this finding has not been reported in other randomized trials,” the researchers wrote.