Every year 15 million babies are born prematurely, which can lead to death or life-long disabilities. It is often caused by a dysfunction of the uterine cervix, which constitutes the narrow channel between the vagina and womb. During pregnancy, this channel must remain closed until the beginning of term labor. A weak cervix may not withstand the weight of the fetus, the amniotic fluid and the placenta and the cervical canal will open and cause late miscarriage or preterm delivery. To prevent this, a band (cerclage) can be applied around the cervix either vaginally or laparoscopically prior to a new pregnancy.

To evaluate which treatment is best for most women, we will randomize (allocate by chance) women at risk for preterm birth, to either vaginal cerclage or laparoscopic cerclage in the Nordic countries and England

Both vaginal and abdominal cerclages are procedures that have been used to prevent preterm birth for more than 50 years. However, only one previous study (MAVRIC, Shennan et al. 2020) has compared the two methods in a randomised trial. Other than evidence from the MAVRIC trial there is uncertainty whether an abdominal cerclage should be preferred over vaginal cerclage, and which women would benefit from it the most.

NORACT is an open, multicenter, superiority, randomized controlled trial with the overall objective to compare laparoscopic versus vaginal cerclage in woman in whom the clinician has equipoise as to whether an elective vaginal or abdominal cerclage will be the best intervention to prevent preterm birth. Participants will be recruited pre-pregnancy or in early pregnancy and randomised to vaginal or laparoscopic cerclage. If randomised to laparoscopic cerclage this will be inserted pre-pregnancy or before 10+0 weeks of gestation. The vaginal cerclage will be inserted during pregnancy, before 16+0 weeks of gestation. A total sample of 188 participants will be included to detect a target difference of 15% in the primary outcome between the two groups. The two primary outcomes are delivery before 32+0 weeks of gestation and baby death. The study extends from sites in Denmark, Sweden, Norway, Finland, Iceland, and the United Kingdom.

Inclusion Criteria:

• Women in whom the clinician has equipoise as to whether an elective vaginal or abdominal cerclage will be the best intervention to prevent preterm birth.
• Not yet pregnant or <10 weeks' pregnant.

Exclusion Criteria:

• Any circumstance under which the clinician is not willing to randomize is an exclusion criterion.
• Any condition or circumstance under which laparoscopic or vaginal cerclage surgery is contraindicated (i.e. on-going pregnancy of more than 10+0 gestational weeks).
• Language difficulties.

Eligibility based on biologic sex.

After publication of the trial results, the final dataset will be publicly available in an anonymized form using i.e. Zenodo open data repository (CERN) or another equivalent database.

Beginning three months and ending three years after the publication of the last trial results.

Data will be available for any research purpose to all interested parties who have approval from an independent review committee. Interested parties will be able to request the data by contacting the trial sponsor. Authorship of publications emerging from the shared data will follow standard authorship guidelines and will include authors from the NORACT Board depending on the nature of their involvement.