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Does Cervix Length Dictate Use of Progesterone?

  • Authors: News Author: Pam Harrison; CME Author: Charles P. Vega, MD
  • CME / CE Released: 11/2/2018
  • Valid for credit through: 11/2/2019
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Target Audience and Goal Statement

This article is intended for primary care clinicians, obstetrician/gynecologists, nurses, pharmacists, and other physicians who treat and manage pregnant women.

The goal of this activity is to provide medical news to primary care clinicians and other healthcare professionals in order to enhance patient care.

Upon completion of this activity, participants will be able to:

  • Assess the efficacy and tolerability of vaginal progesterone among pregnant women at risk for preterm delivery
  • Compare placement of a cervical pessary vs vaginal progesterone among pregnant women at risk for preterm delivery


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News Author

  • Pam Harrison

    Freelance writer, Medscape


    Disclosure: Pam Harrison has disclosed no relevant financial relationships.

CME Author

  • Charles P. Vega, MD, FAAFP

    Clinical Professor, Health Sciences
    Department of Family Medicine
    University of California, Irvine School of Medicine


    Disclosure: Charles P. Vega, MD, has disclosed the following relevant financial relationships:
    Served as an advisor or consultant for: Johnson & Johnson Pharmaceutical Research & Development, L.L.C.; Shire Pharmaceuticals; Sunovion Pharmaceuticals Inc.
    Served as a speaker or a member of a speakers bureau for: Shire Pharmaceuticals


  • Esther Nyarko, PharmD

    Associate CME Clinical Director, Medscape, LLC


    Disclosure: Esther Nyarko, PharmD, has disclosed no relevant financial relationships.

CME Reviewer/Nurse Planner

  • Amy Bernard, MS, BSN, RN-BC, CHCP

    Lead Nurse Planner, Medscape, LLC


    Disclosure: Amy Bernard, MS, BSN, RN-BC, CHCP, has disclosed no relevant financial relationships.

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Does Cervix Length Dictate Use of Progesterone?

Authors: News Author: Pam Harrison; CME Author: Charles P. Vega, MDFaculty and Disclosures

CME / CE Released: 11/2/2018

Valid for credit through: 11/2/2019


Clinical Context

Vaginal progesterone is effective and well-tolerated among pregnant women with a sonographic cervical length of 25 mm or less. That is the conclusion of a systematic review and meta-analysis by Romero and colleagues, published in the February 2012 issue of the American Journal of Obstetrics and Gynecology.[1]

Specifically, researchers collected randomized controlled trials of vaginal progesterone applied during the second trimester with the goal of reducing the risk for preterm delivery. Women included in the review had a sonographic cervical length of 25 mm or less.

Five studies that included a total of 775 women were included in the meta-analysis. The relative risk for preterm delivery at less than 33 weeks of gestation was 0.58 (95% confidence interval, 0.42-0.80) in comparing the progesterone and placebo groups. This translated to a number needed to treat of 11.

Progesterone was also effective in preventing preterm birth when different definitions by gestational age were employed. The relative risk of perinatal mortality in the progesterone vs placebo groups was 0.63 (95% confidence interval, 0.34-1.18). However, infants of women treated with progesterone were less likely to have respiratory distress syndrome and to be admitted to the neonatal intensive care unit.

A cervical pessary has also been studied in the prevention of preterm delivery among women with a short cervix. The current study assesses a cervical pessary vs vaginal progesterone among women at risk for preterm delivery.

Study Synopsis and Perspective

Women with a short cervix treated with a cervical pessary for the prevention of early preterm birth are equally as likely as those treated with vaginal progesterone to give birth before 34 weeks of gestational age, the open-label PESAPRO study indicates.

However, the cervical pessary is associated with more adverse events, and as a result, intravaginal progesterone should be considered the treatment of choice for the majority of at-risk women, the study authors conclude.

A cervical pessary is a silicone device that is placed around the cervix transvaginally. It supports the cervix and reduces direct pressure from the uterus on the cervical canal by directing the cervix toward the sacrum.

"A cervical pessary was not noninferior to vaginal progesterone for preventing spontaneous birth before 34 weeks of gestation in pregnant women with short cervixes," Sara Cruz-Melguizo, MD, from the Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain, and colleagues report in their study, published online September 7 in Obstetrics & Gynecology.[2]

"Considering that there is good-quality clinical evidence supporting the effectiveness of progesterone and a higher rate of vaginal discharge and discomfort reported by pessary users, we recommend the use of vaginal progesterone as a first option," the investigators observe.

In a podcast, the editor-in-chief of Obstetrics & Gynecology, Nancy Chescheir, MD, agreed, pointing out that the burden on patients who used the cervical pessary was higher than it was for women who used intravaginal progesterone.

"Given that the pessary is not noninferior to progesterone, progesterone is a better choice for most women," she concluded, with the exception of women who do not like the idea of using daily progesterone.

Identical Results for Both Options

The literature suggests that women with a short cervical length of 25 mm or less are more likely to experience a spontaneous preterm delivery than women with a longer cervix, say Dr Cruz-Melguizo and colleagues in their article.

Meta-analyses of randomized trials involving pregnant women who had a short cervical length have shown that the prophylactic use of progesterone results in a significantly lower rate of preterm delivery and neonatal death than placebo, they note.

An alternative approach is the transvaginal placement of a cervical pessary. Randomized controlled trials that have been published about the use of a cervical pessary in singleton pregnancies in women with a short cervix have provided contradictory results.

The PESAPRO study was a multicenter, randomized, noninferiority trial involving 254 patients, 246 of whom were included in the intention-to-treat analysis.

"Pregnant women with singleton pregnancies and a short cervix (25 mm or less) at the second-trimester...ultrasonography (19-22 weeks of gestation) were eligible to enroll in the trial," they elaborate.

Patients randomly assigned to the pessary device had it inserted by an obstetrician. Those randomly assigned to the vaginal hormone (200 mg/day micronized progesterone) were instructed to insert the medication vaginally, preferably before bed.

Treatment was initiated at approximately 20 to 23 weeks of gestation, and both treatments were discontinued around the 37-week gestational mark.

"The primary outcome was the proportion of spontaneous births before 34 weeks of gestation," Dr Cruz-Melguizo and colleagues note.

Spontaneous delivery before 34 weeks of gestation occurred in 14% of the pessary group and 14% of the progesterone group in both the intention-to-treat and per protocol analysis.

The risk for spontaneous delivery before 34 weeks of gestation also did not differ in women with a cervical length of 15 mm or less vs 15 mm or more, or by parity status, history of previous preterm delivery, or nature of bacteriologic cultures at randomization.

However, in the subgroup of women with an absent cervical gland area on enrollment, intravaginal progesterone was more effective than the pessary for preventing delivery at less than 34 weeks of gestation.

In this subgroup of women, only 7% assigned to vaginal progesterone gave birth before 34 weeks' gestation compared with 25% of women assigned to the cervical pessary device.

As investigators explain, the absence of a cervical gland on ultrasound suggests that these women have a more mature cervix.

More Adverse Effects With Cervical Pessary

Rates of vaginal discharge were high in both groups, but were higher in the cervical pessary group, at 87%, compared with 71% for women treated with intravaginal progesterone (P=.002).

Similarly, women assigned to the cervical pessary group were more likely to report vaginal discomfort, at 27%, compared with only 3% for those treated with the intravaginal hormone (P<.001).

The investigators point out that 22% of women who had the cervical pessary described it as an unpleasant experience, although only 3% reported that it was unbearably painful.

The authors have reported no relevant financial relationships.

Obstet Gynecol. Published online September 7, 2018.

Study Highlights

  • This open-label, randomized trial was conducted at 27 medical centers in Spain. The principal outcome of the study was noninferiority of a cervical pessary vs vaginal progesterone at preventing preterm delivery among high-risk women.
  • Women included in the study had a singleton pregnancy and an estimated cervical length of 25 mm or less on routine second trimester ultrasound.
  • Women younger than 18 years and women with other potentially significant complications of pregnancy were excluded from study participation.
  • Participants received either a cervical pessary placed by a trained obstetrician or micronized vaginal progesterone at a dose of 200 mg/day.
  • Study treatment was initiated between 20 and 24 weeks of gestation, and it was discontinued in week 37 of pregnancy. Women were evaluated monthly by clinical staff during this treatment period.
  • The primary study outcome was the risk for preterm birth before 34 weeks of gestation. Researchers also followed rates of maternal and neonatal adverse events and birth weight.
  • 254 women underwent randomization. The mean maternal age was slightly less than 33 years, and nearly half the study cohort was nulliparous. The median cervical length at randomization was 20.9 mm.
  • The rate of preterm delivery in both the progesterone and pessary groups was 14%, demonstrating noninferiority between these 2 methods.
  • In subgroup analyses based on women's parity, cervical length, and other factors, only the absence of the cervical gland area on baseline ultrasound altered the main study conclusion of noninferiority between treatments. Vaginal progesterone was more effective than pessary at preventing preterm delivery in this subgroup.
  • Rates of sick leave from work and emergency department visits were similar in the 2 treatment groups. However, women in the pessary group were more likely to visit the emergency department in the first month after randomization.
  • Rates of vaginal discomfort in the pessary and progesterone groups were 27% and 3%, respectively. Vaginal discharge was also significantly more common in the pessary cohort; 3% of women in the pessary group had their device removed before 34 weeks of gestation because of adverse events.
  • There were no differences between the pessary and progesterone groups in rates of pelvic pain, infection, or sexual activity.
  • Neonatal birth weights were similar in the pessary and progesterone cohorts, as were the rates of perinatal mortality and other negative neonatal outcomes.

Clinical Implications

  • A previous meta-analysis found that vaginal progesterone effectively reduced the risk for preterm delivery at different gestational ages among women with a cervical length of 25 mm or less. Vaginal progesterone was associated with significant reductions in the risks for respiratory distress syndrome and admission to the neonatal intensive care unit, but it had a nonsignificant effect in reducing perinatal mortality.
  • The current study demonstrates similar rates of preterm delivery among women with a short cervix treated with either a cervical pessary or vaginal progesterone. Rates of sick leave were similar between the 2 groups, although vaginal discomfort and discharge were more common in the pessary cohort. Rates of infection were similar in the 2 groups.
  • Implications for the Healthcare Team: The current study suggests that cervical pessary may be a reasonable option to prevent preterm delivery among women with a cervical length of 25 mm or less. The healthcare team should discuss the risks associated with this finding with patients, and should explore patient preferences regarding potential treatment.

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