Estimated Fetal Weight (Hadlock)
Estimates fetal weight from ultrasound measurements using Hadlock 4-parameter formula.
Score interpretation
Interpret against a gestation-specific centile chart: an EFW below the 10th centile suggests a small-for-gestational-age fetus (RCOG Green-top Guideline 31).
→ Plot on a customised or population centile chart and follow the local SGA / fetal growth pathway if below the 10th centile.
EFW ≥4000g: Macrosomia. Increased risk of shoulder dystocia and operative delivery.
→ Diabetic screen if not done. Discuss birth plan. Consider induction if EFW >4500g or symptomatic. Shoulder dystocia simulation recommended for attending team.
Interpretation bands for the EFW (Hadlock). Apply clinical judgement and local guidance.
References
- Hadlock FP et al. Estimation of fetal weight with the use of head, body, and femur measurements. Am J Obstet Gynecol. 1985.
Related
Curated clinical cross-links plus same-class fallbacks.
- Minoxidil · Direct vasodilator / hair-growth stimulator
- Pegvisomant · Growth Hormone Receptor Antagonist
- Somatropin (Recombinant Human Growth Hormone) · Growth Hormone Replacement
- Somapacitan · Long-acting growth hormone analogue
- Enoxaparin · Low Molecular Weight Heparin (LMWH)
- Tinzaparin sodium · Low molecular weight heparin
- Spinal Anaesthesia Hypotension Management · AAGBI; ASA
- Pre-Eclampsia / Eclampsia in ED · NICE NG133; RCOG Green-top 10A
- Suspected Ectopic Pregnancy · NICE NG126; RCOG Green-top 21
- Polycystic Ovary Syndrome (PCOS) · International PCOS Guideline 2023; NICE CKS
- Pre-eclampsia Management · NICE NG133 2019
- Ectopic Pregnancy · NICE CG154 / RCOG GTG 21
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.