Rationale and design of SuPPoRT: a multi-centre randomised controlled trial to compare three treatments: cervical cerclage, cervical pessary and vaginal progesterone, for the prevention of preterm birth in women who develop a short cervix

Table 1 Summary of study visits

Procedure	Screening & randomisation 14⁺⁰-23⁺⁶ weeks gestation	Intervention (day 0) 14⁺⁰-23⁺⁶ weeks gestation	Baseline visit (day) 1–4 weeks after procedure	Follow up visits (if clinically indicated)	Final visit 34⁺⁰-38⁺⁶ weeks’ gestation	Note review (no visit required)
Visit window (± days)	−7 to 0 days	Day 0	7-28 days	Approximately 2–4 weekly	3	Discharge from Hospital or 28 days postnatal
Informed consent	✓
Medical history and concomitant medications	✓		✓	Optional	✓
Transvaginal ultrasound Scan	✓		✓	Optional
Biological sample collection	Optional		Optional	Optional
Adverse events (AEs) changes to interventions			✓	As needed	✓	✓
Count of un-used medication					✓
Pessary/Cerclage removal					✓

ISSN: 1471-2393