Evaluation of a two-tier preterm birth prevention service in a tertiary hospital in the United Kingdom: a retrospective cohort study.
Shea M., Longo C., LeThanh V., Vandepitte N., Hemelaar J.
BACKGROUND: Preterm birth is the most important cause of neonatal morbidity and mortality. Clinical guidelines recommend assessment of risk of preterm birth and implementation of interventions to reduce preterm birth risk through dedicated preterm birth clinics. We hypothesized that a two-tier preterm birth clinic pathway can safely manage women at the highest risk of preterm birth while reducing intervention for women at moderate risk of preterm birth. We aimed to test this hypothesis by evaluating risk factors, management, and outcomes of women attending a two-tier preterm birth prevention service. METHODS: We conducted a retrospective cohort study of women who gave birth between January and June 2021 at a tertiary hospital in Oxford, UK. We included two cohorts: women attending a Cervical Screening Clinic and women attending a Preterm Birth Clinic, and we also reviewed all cases of births before 34 weeks over that time period. At the initial midwife appointment at 8-10 weeks' gestation, risk factors for preterm birth were assessed. Pregnant women with moderate risk factors (previous preterm birth at 32+ 0 - 33+ 6 weeks, previous preterm prelabour rupture of membranes (PPROM) at 32+ 0 - 33+ 6 weeks, previous LLETZ / cone biopsy, known abnormal uterus, previous caesarean section at 10 cm dilatation, and multiple pregnancy) were referred to the Cervical Screening Clinic for a cervical length scan by a sonographer. Pregnant women with major risk factors (previous preterm birth at 16+ 0 - 31+ 6 weeks, previous PPROM at less than 32+ 0 weeks, radical trachelectomy, previous cervical cerclage) as well as those with a cervix