Synopsis
Distinguish symptoms suggesting early labour from established birth or another emergency, select an appropriate diagnostic pathway and initiate gestation-specific neonatal protection without avoidable delay.
- Preterm labour assessment begins with gestation, symptoms, maternal observations, fetal wellbeing and membrane status.
- A sterile speculum examination can assess fluid, bleeding and cervical appearance; collect any indicated biomarker sample before digital examination.
- For clinically suspected labour at 29+6 weeks or earlier, NICE advises treatment without waiting for a cervical-length exclusion test.
- At 30+0 weeks or later with intact membranes, transvaginal cervical length of 15 mm or less supports diagnosed labour; more than 15 mm makes birth within 48 hours less likely.
- Hologic fFN cassettes have been discontinued: services need the NHS England interim pathway, including Actim Partus where specified, rather than an unavailable test.
- The legacy NICE fFN threshold is negative at 50 ng/mL or less and positive above 50, but only applies if the correct assay is genuinely available.
- Nifedipine may briefly delay suitable intact-membrane labour for steroids or transfer; significant infection, bleeding or fetal compromise may contraindicate delay.
Key red flags
Fever with uterine tenderness, offensive fluid or maternal deterioration raises concern for infection and makes delaying birth potentially harmful.
Heavy bleeding, persistent severe pain or an abnormal fetal heart rate requires evaluation for abruption or another emergency before considering tocolysis.
Investigation priorities
Assess the cervix, bleeding and fluid while identifying established labour or another urgent problem.
Management branches
A patient before 37 weeks reports symptoms compatible with early labour.
- Establish dating, observations, symptom progression and fetal wellbeing, and assess for bleeding, infection, membrane rupture or cord prolapse.
- Perform a consented speculum examination and collect appropriate samples, then decide whether the patient has established labour or requires further risk assessment.
- Treat maternal illness and arrange urgent delivery where necessary before considering medicines intended to prolong pregnancy.
Key medicines
Nifedipine for short-term tocolysisPrescribe oral nifedipine under the maternity unit's defined immediate-release or modified-release loading and maintenance regimen, with an explicit maximum dose and usually a 48-hour stop point; formulations and schedules are not interchangeable.This indication is off label. Record blood pressure and pulse, avoid clinically important hypotension and conditions requiring delivery, and review combined vasodilator or magnesium treatment.
Atosiban when nifedipine is contraindicatedGive 6.75 mg intravenously over 1 minute, then infuse 18 mg/hour for 3 hours followed by 6 mg/hour for up to 45 hours; the course must not exceed 48 hours and preferably not 330.75 mg total.Do not use to delay delivery with fetal compromise, significant haemorrhage, abruption or suspected intrauterine infection; check the SmPC restrictions including placenta praevia and membrane rupture.