How this instrument works
The Finnegan Neonatal Abstinence Syndrome (NAS) score is a structured way to document and track withdrawal signs in a newborn exposed to opioids or certain other substances in utero. Developed by Loretta Finnegan in the 1970s, it's used in nurseries and NICUs to standardize what would otherwise be a subjective bedside impression into a repeatable, numeric assessment performed at regular intervals — commonly every few hours — by trained nursing or medical staff.
The version implemented here is the commonly used 'Modified Finnegan' 21-item scale: signs grouped roughly into central nervous system disturbances (cry, sleep, Moro reflex, tremors, tone, skin breakdown, myoclonic jerks, seizures), metabolic/vasomotor/respiratory signs (sweating, fever, yawning, mottling, nasal stuffiness, sneezing, nasal flaring, fast breathing), and gastrointestinal signs (excessive sucking, poor feeding, regurgitation, projectile vomiting, and loose or watery stools). Each sign has its own point value reflecting how strongly it's associated with withdrawal severity — a generalized convulsion, for example, carries far more weight than mild yawning — and the total is simply the sum of whatever signs are present at the time of assessment.
A single score is a snapshot, not the basis for a clinical decision on its own. NAS assessment protocols are built around watching the trend across consecutive scores, scored at set intervals by staff trained to apply the tool consistently, because withdrawal severity fluctuates and a single elevated reading can reflect a transient state (like a baby who was just handled or fed) rather than a sustained clinical picture.
- Score cry, sleep after feeding, Moro reflex, tremors when disturbed, and tremors when undisturbed using the listed severity options for each.
- Set the yes/no signs — increased muscle tone, excoriation, myoclonic jerks, generalized convulsions, sweating, frequent yawning, mottling, nasal stuffiness, sneezing, nasal flaring, excessive sucking, poor feeding, regurgitation, and projectile vomiting — based on the infant's current presentation.
- Score temperature, respiratory rate, and stool consistency using the listed categories for each.
- Read the total Finnegan NAS score, and interpret it as one point in a series of assessments rather than in isolation.
Worked example — moderate presentation, total score 13
An infant is assessed with a high-pitched cry lasting under 5 minutes (2 points), sleep shortened to under 3 hours after feeding (1), a hyperactive Moro reflex (2), mild tremors when disturbed (1), increased muscle tone (1), sweating (1), a mild fever of 37.2-38.3°C (1), frequent yawning (1), nasal stuffiness (1), a respiratory rate over 60/min (1), and poor feeding (1). Every other item — including tremors when undisturbed, excoriation, myoclonic jerks, convulsions, mottling, sneezing, nasal flaring, excessive sucking, regurgitation, projectile vomiting, and stools — is absent or normal, scoring 0.
Summed across all 21 items, the total is 13: 2+1+2+1+0+1+0+0+0+1+1+1+0+1+0+0+1+0+1+0+0+0 = 13. On its own, 13 is above the single-score threshold (≥8) commonly cited as significant, but clinical practice bases actual treatment decisions on the trend across consecutive assessments — for example, two consecutive scores of 12 or higher, or three consecutive scores averaging 8 or higher — not on one isolated reading.
Questions
Does a single Finnegan score above 8 mean the infant needs treatment?
Not by itself. Clinical protocols for acting on the Finnegan score are built around trends across consecutive, regularly spaced assessments — commonly, two consecutive scores of 12 or higher, or three consecutive scores averaging 8 or higher — rather than any single reading. A single elevated score is a prompt to reassess and continue monitoring closely, not an automatic trigger for pharmacologic treatment. The treatment decision itself is made by the clinical team caring for the infant.
Who developed the Finnegan score and when?
Loretta Finnegan and colleagues developed it in the 1970s to standardize assessment of withdrawal in infants born to opioid-dependent mothers, publishing the original tool in Addictive Diseases in 1975. The scale in wide clinical use today, including the version implemented here, is commonly referred to as the 'Modified Finnegan' — a 21-item version building on that original work.
Why does the score include so many different signs?
Neonatal withdrawal shows up across multiple body systems at once — the central nervous system (tremors, an overactive Moro reflex, high-pitched crying), the autonomic/vasomotor system (sweating, mottled skin, fever), the respiratory system (fast breathing, nasal flaring), and the gastrointestinal system (poor feeding, loose stools). Scoring across all of these together gives a fuller picture than any single sign could, and different infants can present with different dominant symptom clusters.
How often is the Finnegan score typically assessed?
Protocols vary by institution, but a common pattern is scoring every 3 to 4 hours, often timed around feeds, continued for a set observation period after birth or after the mother's last substance use, and adjusted based on the infant's trend. The specific interval and duration of monitoring are set by hospital or unit protocol, not by the score itself.
Can something other than opioid exposure cause a high Finnegan score?
Yes — many of the individual signs (jitteriness, poor feeding, loose stools, temperature instability) can have causes unrelated to withdrawal, such as sepsis, hypoglycemia, or hypocalcemia, especially in a newborn with no known prenatal substance exposure. That's part of why the score is used alongside a documented exposure history and clinical evaluation, not as a standalone diagnostic test.
Is this calculator meant for parents to score their baby at home?
No. The Finnegan NAS score is designed to be applied by trained nursery or NICU staff using standardized observation technique, typically in a hospital setting where the infant can be examined directly and reassessed on a fixed schedule. It is a clinical documentation and monitoring tool, not a home symptom checker.
References
- Finnegan LP, Connaughton JF, Kron RE, Emich JP. — Neonatal Abstinence Syndrome: Assessment and Management, Addict Dis. 1975;2(1-2):141-158 (PMID 1163358)
- MDCalc — Finnegan Neonatal Abstinence Syndrome (NAS) Scoring System
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.