👶 New Ballard Score (Gestational Age)
Estimate neonatal gestational age with the New Ballard Score.
New Ballard Score (Gestational Age)
Neuromuscular maturity subtotal (6 items: posture, square window, arm recoil, popliteal angle, scarf sign, heel-to-ear) (points)
Physical maturity subtotal (6 items: skin, lanugo, plantar surface, breast, eye/ear, genitals) (points)
When to use
Assign gestational age when dating is unknown or discordant with the exam.
How it works
GA (weeks) = 24 + 0.4 × total of neuromuscular (6 items) and physical (6 items) maturity subtotals; total −10 to 50 maps to ~ 20–44 weeks.
Key points
- Accuracy ± 2 weeks; most accurate at 12–48 h of life.
- May overestimate in small-for-gestational-age infants.
- Cross-check with prenatal ultrasound/LMP.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.