Growth & NutritionPhysiology

New Ballard Score

Q: How accurate is the Ballard score?

It estimates gestational age within roughly ±2 weeks and is best performed within about 12–48 hours of birth.

The New Ballard Score estimates gestational age from 12 physical and neuromuscular maturity criteria (Ballard et al., 1991). It was extended to include extremely premature infants (<26 weeks) and remains the standard bedside tool for gestational age assessment when antenatal dates are unavailable or uncertain. Scores range from –10 (≈20 weeks) to 50 (≈44 weeks).

Neuromuscular (6 criteria)

Flexor tone develops with gestational age. Posture, wrist angle, arm recoil, popliteal angle, scarf sign, and heel-to-ear resistance each reflect neuromuscular maturity.

Physical (6 criteria)

Skin, lanugo, plantar creases, breast bud, ear cartilage, and genital development follow predictable maturational sequences independently of neurologic status.

Score → GA formula: Estimated GA (weeks) = (total score × 2/5) + 24. Each 5-point increment corresponds to approximately 2 weeks of gestation.

Educational tool only. Clinical decisions should be based on direct patient assessment and institutional protocols. Best performed within 12–96 hours of birth.

Assigned sex at birth:

Neuromuscular Maturity

0/6 · subtotal: 0

Posture

Square Window

Arm Recoil

Popliteal Angle

Scarf Sign

Heel to Ear

Physical Maturity

0/6 · subtotal: 0

Skin

Lanugo

Plantar Surface

Breast

Eye / Ear

Genitals

—score

Estimated Gestational Age

—

Select criteria above to begin

Pearls for trainees:

Perform the Ballard exam within 12 hours of birth for most accuracy; up to 96 hours is acceptable.
The neuromuscular exam is best performed when the infant is quiet and alert — crying increases tone and alters results.
For infants below 26 weeks, scores are often –1 on many criteria; don't be surprised to see a negative total.
The score is an estimate, not a diagnosis. Combine with last menstrual period dates and antenatal ultrasound dating.
Accuracy is ±2 weeks. A score of 30 could mean anywhere from 34 to 38 weeks.

Reference: Ballard JL, Khoury JC, Wedig K, et al. New Ballard Score, expanded to include extremely premature infants. J Pediatr. 1991;119(3):417–423.

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Frequently asked questions

How accurate is the Ballard score?

It estimates gestational age within roughly ±2 weeks and is best performed within about 12–48 hours of birth.

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