CLINICAL TOOL
FGR Delivery Timing Calculator
Clinical guideline tool based on TRUFFLE and ISUOG guidelines to determine the optimal delivery timing for Fetal Growth Restriction (FGR) based on biometry and Dopplers.
About this page
This is a clinician-reviewed evidence brief, not an interactive calculator. It summarises the guideline logic our subspecialists apply when managing these cases every day. For a case-specific assessment, request a consultation or refer your patient.
Clinical Purpose
To synthesize complex fetal parameters (gestational age, EFW centile, Umbilical Artery Doppler, MCA Doppler, Ductus Venosus Doppler, and CTG) to recommend the safest timing for delivery in early and late FGR.
Inputs
- Gestational Age
- Estimated Fetal Weight (EFW) Centile
- Umbilical Artery (UA) Doppler (Normal, PI > 95th, AEDF, REDF)
- Middle Cerebral Artery (MCA) Doppler
- Ductus Venosus (DV) Doppler
- Computerized CTG (cCTG) Short-Term Variation (STV)
Formula & Guideline Source
TRUFFLE Study (2015), ISUOG Practice Guidelines (2020), SMFM Consult Series #52.
Limitations
These are general recommendations. Individualized care is required. The decision to deliver an extremely premature FGR fetus involves multidisciplinary counseling regarding neonatal morbidity, mortality, and the availability of advanced NICU care.
FAQ
When is delivery indicated for absent end-diastolic flow (AEDF) in the umbilical artery?
According to ISUOG guidelines, delivery is typically recommended from 32-34 weeks of gestation in the presence of persistent AEDF, following administration of antenatal corticosteroids.
How does late FGR (≥32 weeks) management differ from early FGR?
Late FGR is less likely to show severe umbilical artery Doppler abnormalities. Management heavily relies on MCA Dopplers (brain sparing) and CPR (cerebroplacental ratio), with delivery generally recommended between 37 and 38 weeks depending on Doppler findings.
References
- Lees CC, et al. ISUOG Practice Guidelines: diagnosis and management of small-for-gestational-age fetus and fetal growth restriction. Ultrasound Obstet Gynecol. 2020.
- Lees CC, et al. 2 year neurodevelopmental and intermediate perinatal outcomes in infants with very preterm fetal growth restriction (TRUFFLE): a randomised trial. Lancet. 2015.