What is an Arabian pessary?

The Arabin Pessary: A Cervical Support Device for Preterm Birth Prevention

The Arabin pessary is a silicone ring-shaped device designed to encircle the cervix and provide support to prevent preterm birth in women with cervical shortening. The Arabin pessary works by altering the uterocervical angle to redirect the weight of the uterine contents away from the internal os, potentially preventing cervical dilation, preserving the cervical mucus plug, and protecting the fetal membranes. 1

Mechanism of Action

• The pessary changes the angle of the uterocervical junction, redirecting pressure from the uterine contents away from the cervix 1
• The caudal portion of the device encircles the cervix, which may prevent cervical dilation and deterioration of the protective mucus plug 1
• It provides mechanical support without requiring medication or surgical intervention 1

Clinical Applications

• Used primarily in women with a short cervix (typically ≤25mm) detected on ultrasound between 18-24 weeks gestation 1
• Considered an alternative to cerclage or vaginal progesterone for preventing preterm birth 1
• Low cost and relatively easy insertion and removal make it an attractive option for many clinical scenarios 1

Effectiveness

• Research shows conflicting results regarding effectiveness:
  • The Pesario Cervical para Evitar Prematuridad trial showed significant reduction in spontaneous preterm birth (6% vs 27%) and improved neonatal outcomes in singleton pregnancies with short cervix 1
  • A multinational study found no difference in preterm birth rates at <34 weeks (12.0% vs 10.8%) compared to expectant management 1
  • In twin pregnancies with short cervix, one RCT showed reduced preterm birth rates (16.2% vs 39.4%) 1

Side Effects and Complications

• Most side effects are minor and include:
  • Increased vaginal discharge (most common) - approximately 15-20% of women require medical evaluation for this 1, 2
  • Discomfort during placement and removal 1
  • Vaginal irritation 1
• Serious complications are rare but can include:
  • Cervical ischemia 1
  • Potential for masking development of vaginal or cervical pathology if not regularly monitored 3
• Rates of vaginal infection are similar between women with and without pessaries 1

Management Considerations

• The pessary typically remains in place until 37 weeks gestation unless complications develop 1
• Regular follow-up is essential to prevent complications 4
• Approximately 11% of women may require early removal due to vaginal discharge, discomfort, or bleeding 1
• The pessary should be removed before performing cervical screening procedures such as Pap smears 2

Patient Selection

• Most effective in women with singleton pregnancies and cervical length <25mm 1
• Results in multiple gestations are mixed, with some studies showing benefit in twins with short cervix 1
• Can be used in combination with vaginal progesterone in women with very short cervix (<15mm) 1

The Arabin pessary represents a non-invasive option for managing cervical shortening and preventing preterm birth, though evidence for its effectiveness varies across different patient populations and clinical scenarios 1.