The Mechanical "Fix" of the Pessary May Not Solve the Problem of Preterm Birth

By Allison Bryant, MD, MPH

Dr. Bryant is an associate editor with NEJM Journal Watch Women's Health, from which this story was adapted. Full coverage is available at the link below.

Placement of a cervical pessary does not lower rates of preterm delivery among at-risk women with singleton pregnancies, according to an international study in the New England Journal of Medicine.

Over 900 women with singleton pregnancies at 20–25 weeks' gestation and cervical lengths below 25 mm were randomized to pessary placement or expectant management (control group). All women with cervical lengths below 15 mm were additionally treated with vaginal progesterone.

Rates of spontaneous delivery before 34 weeks' gestation were similar in the pessary and control groups (12% and 11%, respectively).

Comment: A previous trial of cervical pessaries generated excitement that this relatively inexpensive, low-tech, well-tolerated intervention might reduce the burden of preterm birth among women with a short cervix. However, the present trial (the largest to date) lends credence to the axiom that a single positive study should not drive a practice change. Perhaps it's too much to expect that a mechanical "fix" can substantially diminish the risk inherent in a multifactorial process like preterm birth.