Variation between countries for routine transvaginal cervical length measurement and interventions to prevent preterm birth.

Objective: To assess the variation between countries for routine transvaginal ultrasound assessment of the cervical length and interventions offered to prevent preterm birth (PTB).

Study Design: An anonymous digital questionnaire was sent out between August and October 2023 to delegates of the European Spontaneous Preterm Birth Congress. Outcomes assessed included method, indications (i.e. singleton pregnancy in women with or without a history of PTB, or a multiple pregnancy), timing and frequency of routine cervical length measurement, interventions offered to pregnant women with a short cervix or a history of PTB, and advice on physical- and sexual activity.

Results: In total, 247 visitors of the European Spontaneous Preterm Birth Congress were approached for this study and 103 (42 %) participants completed the questionnaire representing 15 countries. Most participants worked in a Public/University hospital (n = 54, 53 %) and worked as a specialist (registrar or consultant; n = 84, 82 %). In most countries, the cervix was measured via a straight-line method without the cervical isthmus, but variety existed also within countries. Routine cervical length measurement in women with no prior PTB or a multiple pregnancy is rarely performed in the first trimester. For women with a history of PTB, 39 (38 %) respondents from six countries reported to start serial cervical measurement in the first trimester and 99 (96 %) from 14 countries in the second trimester. Follow-up for women at risk for PTB mainly occurs fortnightly (n = 40, 39 %) or monthly (n = 14, 14 %). However, follow-up is often individualized according to patient's history and/or cervical length. In women with a history of PTB or a short cervix progesterone is administered vaginally (n = 99, 96 %), however dosage vary between 100 mg and 400 mg daily. The timing and gestational age at which a (primary/secondary/tertiary) vaginal cerclage is offered widely differ between countries (e.g. up to 24-28 weeks of gestation for a secondary cerclage). Advice on restrictions regarding sexual activity in pregnancy is frequently prescribed for women with a short cervix (n = 38, 37 %).

Conclusion: Substantial variation exist between and within countries regarding the indications and timing of cervical length measurement and interventions offered. There is a need for a more universal approach to manage patients at risk for PTB based on the existing evidence.