Synopsis
Identify pathological failure of fetal growth, combine growth trajectory with placental and fetal assessment, and choose surveillance and birth timing proportionate to deterioration risk.
- Fetal growth restriction means failure to achieve growth potential; it is not synonymous with a weight estimate below the tenth centile.
- Assess both absolute size and growth velocity, together with Dopplers, amniotic fluid, fetal movements and maternal disease.
- An estimated fetal weight or abdominal circumference below the third centile raises particular concern even before other abnormalities appear.
- Umbilical artery Doppler evaluates placental resistance; a normal result does not exclude late-onset growth restriction.
- Aspirin can prevent placental disease in selected higher-risk pregnancies but does not reverse established fetal growth restriction.
- The delivery decision weighs the risk of remaining in utero against prematurity and must be updated when maternal or fetal findings change.
Key red flags
Reduced or changed movements require immediate maternity contact even if the last growth scan was reassuring.
Absent or reversed umbilical artery end-diastolic flow requires urgent specialist assessment of fetal condition and the appropriate place and timing of care.
Severe maternal headache, visual symptoms, hypertension or epigastric pain alongside poor fetal growth requires assessment for pre-eclampsia.
Investigation priorities
Establish accurate gestation and assess fetal size and interval growth.
Management branches
Antenatal risk assessment identifies a greater likelihood of placental disease or impaired growth.
- Address smoking and maternal disease, and prescribe low-dose aspirin when the applicable pre-eclampsia or placental-risk criteria are met.
- Arrange serial ultrasound surveillance for higher-risk pregnancies and use symphysis-fundal height appropriately in lower-risk singleton care.
- Provide clear information about fetal movements and make sure an abnormal measurement produces a booked assessment rather than an untracked recommendation.