Preterm birth clinic interventions and pregnancy outcomes*
| Characteristics | Proportion (%) or mean (SD) |
| Shortest transvaginal cervical length measurement | |
| Mean (SD) (in mm) | 27.0 (9.1) |
| Range (in mm) | 0–39 |
| No <25 mm (threshold for intervention) | 21/72 (29.2) |
| Treatments given to reduce the risk of preterm birth | |
| Cervical cerclage only | 16/72 (22.2) |
| Vaginal progesterone only | 4/72 (5.6) |
| Both cervical cerclage and vaginal progesterone | 10/72 (13.9) |
| No treatment | 40/72 (55.6) |
| Antenatal hospital admission from clinic due to preterm birth risk | 2/72 (2.8) |
| Risk of preterm birth for those who had an exit visit† | |
| Low | 45/66 (68.2) |
| Intermediate | 18/66 (27.3) |
| High | 3/66 (4.5) |
| Pregnancy outcome | |
| Termination of pregnancy for fetal anomalies | 2/72 (2.8) |
| First trimester miscarriage (<13+0 weeks) | 1/72 (1.4) |
| Second trimester loss (13+1 to 22+6 weeks) | 2/72 (2.8) |
| Extremely early preterm birth (23+0 to 27+6 weeks)‡ | 3/72 (4.2) |
| Very early preterm birth (28+0 to 31+6 weeks) | 1/72 (1.4) |
| Moderate to late preterm birth (32+0 to 36+6 weeks) | 11/72 (15.3) |
| Term birth (≥37+0 weeks) | 52/72 (72.2) |
| Mode of birth for pregnancies that reached ≥20+0 weeks§ | |
| Normal vaginal birth | 44/68 (64.7) |
| Instrumental birth | 7/68 (10.3) |
| Caesarean section | 17/68 (25.0) |
| Neonatal outcome for pregnancies that reached ≥20+0 weeks§¶ | |
| Alive at hospital discharge | 67/69 (97.1) |
| Early neonatal death | 1/69 (1.4) |
| Stillbirth | 1/69 (1.4) |
*Excluding one with all follow-up at local hospital after first visit as no further data collected.
†Risk assessment defined in online supplemental table 4. Quantitative fetal fibronectin was included in 29/66 (44%) cases. Excludes six women who did not have an exit appointment. Includes three women who did not complete Set 3 questionnaires—for two the exit visit was their second visit, both were high risk and delivered prior to planned completion of the set 3 questionnaires by post; and one who declined.
‡Includes one prelabour fetal demise.
§Excluding one termination of pregnancy >20 weeks.
¶Includes one set of twins.