Due to slow recruitment and an interim analysis showing no benefit of occlusion.

The aim of this study was to evaluate the effect of cervical occlusion versus no cervical occlusion in women with cervical cerclages.

Cervical weakness and ascending infection have long been considered important causes of preterm birth. Cervical occlusion could theoretically be used for the treatment of cervical weakness and to protect the cervix against infection. A cervical cerclage could be placed to increase the cervical resistance, and occlusion of the external os could be performed to retain the cervical mucus plug thereby preventing infection. The aim of this multicentre, stratified, randomised controlled trial was to evaluate the effect of cervical occlusion versus no cervical occlusion in women with prophylactic and therapeutic cervical cerclages.

Inclusion Criteria:

• The physician in charge considered that a cerclage was indicated.
• Gestational age between 12 and 27 completed weeks.
• Previous late mid-trimester miscarriage, or spontaneous preterm labour and delivery before 28 weeks with or without previous cerclages.
• Previous cerclage because of short cervix.
• Confirmed gestational age defined as gestational age estimated by ultrasound at less than or equal to 22+0 weeks, and/or certain last menstrual period.
• Vaginal infection treated before cerclage.
• Ability to read and understand the relevant national language.
• Consent obtained in accordance with specifications of the local research ethics committee.
• 18 years or more of age and legally competent.

Exclusion Criteria:

• Demonstrated cervical infection.
• Obstetrical complications in the current pregnancy.
• Multiple pregnancies.
• History of a significant abruptio placenta in a previous pregnancy.