Cervical Occlusion for the Prevention of Preterm Birth

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.