Preventing and reducing the morbidity and mortality of preterm birth in singleton pregnancies

M R C O G PA R T 2 · S O S P O C K E T C A R D · K N O W L E D G E A R E A 5 – A N T E N ATA L C A R E

Preventing and Reducing the Morbidity and Mortality of Preterm Birth in Singleton Pregnancies Creswell L, et al. Preventing and reducing the morbidity and mortality of preterm birth in singleton pregnancies. TOG 2025;27:104–114. doi:10.1111/tog.12973

13.4m ~1m ~50% PRETERM BIRTHS/YEAR (9.9% OF ALL BIRTHS) DEATHS <5Y FROM PREMATURITY UK PTBS THAT ARE PROVIDER-INITIATED COMPLICATIONS

DO N' T-M IS S FA C TS

1. Ultrasound-indicated cerclage: ≥1 previous sPTB/STM + CL <25 mm before 24 weeks. History-indicated: ≥3 previous sPTB/STM. TAC: previous failed cerclage with delivery <28 weeks

2. Emergency cerclage only if no intra-amniotic infection, PPROM, continuous bleeding or established labour, and before 24 weeks

3. MAVRIC: TAC beats TVC after failed TVC (PTB <32w 8% vs 33%/38%); low vs high TVC no difference

4. Vaginal progesterone = progestogen of choice; 17-OHPC withdrawn by FDA after PROLONG (11.0% vs 11.5%)

5. Cervical pessary trial stopped early – excess fetal/neonatal/infant death (RR 1.94, 1.13–3.32); no benefit (RR 1.00)

6. Antenatal corticosteroids ideally <7 days before birth; interval >7 days → higher in-hospital mortality

7. MgSO₄ for neuroprotection if birth expected <34 weeks – CP RR 0.71; no increase in caesarean rate

8. Tocolysis buys 48 h (up to 7 days) for steroids/MgSO₄/in-utero transfer only — contraindicated in PPROM

9. Aspirin before 16 weeks after FMF first-trimester screening prevents preterm pre-eclampsia (iatrogenic PTB)

THREE TIERS OF PREVENTION

Primary: dating scan, antenatal care, nutrition (omega-3 if deficient), infection treatment, avoid iatrogenic PTB

Secondary: vaginal progesterone · cervical cerclage Secondary – not supported: cervical pessary

Tertiary: antenatal corticosteroids · MgSO₄ <34w · tocolysis for 48h · neonatal care/in-utero transfer

ABBREVIATION KEY

PTB — preterm birth (<37 weeks, WHO) PPROM — preterm prelabour rupture of membranes

PSC — preterm birth surveillance clinic 17-OHPC — 17-alpha-hydroxyprogesterone caproate

SBLCB — Saving Babies Lives Care Bundle CP — cerebral palsy

CL — cervical length NND — neonatal death

qfFN — quantitative fetal fibronectin MgSO₄ — magnesium sulphate

QUiPP — Quantitative Innovation in Predicting Preterm Birth app HIC / LIC — high-income / low-income country

TVC / TAC — transvaginal / transabdominal cerclage BV — bacterial vaginosis

STM — second trimester miscarriage aOR / aRR — adjusted odds ratio / adjusted risk ratio

Source: The Obstetrician & Gynaecologist (TOG), RCOG journal — 2025;27:104–114. doi:10.1111/tog.12973

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