Newborn · Bilirubin
Newborn Jaundice & Bilirubin Nomogram (AAP 2022)
Is my baby's jaundice serious? Plot the bilirubin level against the AAP 2022 phototherapy line for your baby's exact hours of age, gestational age, and risk factors. Plus a parent's guide to spotting jaundice, feeding through it, and when to call.
Last reviewed 28 May 2026
AAP 2022 newborn bilirubin nomogram
Phototherapy threshold — neonatal jaundice
h
wk
mg/dL
Enter postnatal age, gestational age, and bilirubin to see the phototherapy line.
Why is my newborn yellow?
What you’re seeing is bilirubin — a yellow pigment from the natural breakdown of red blood cells. Your baby was born with extra red cells (they needed more to survive in the low-oxygen womb environment); those extras are now being recycled. The liver enzyme that gets rid of bilirubin (called UGT1A1) is still ramping up over the first few weeks. While bilirubin production outpaces clearance, it accumulates in skin and the whites of the eyes — jaundice. About 60% of full-term babies and 80% of preterm babies get some degree of jaundice. Most is harmless and resolves on its own.
When should I worry about my baby’s jaundice?
Call your midwife / GP / paediatrician same-day if:
- Jaundice in the first 24 hours of life — this is never normal and needs an urgent bilirubin test.
- Bright yellow rather than light tan.
- Yellow extending past the belly button down to the legs and palms / soles (check in NATURAL daylight, not lamps).
- Baby very sleepy, hard to wake, floppy, not feeding well.
- Fewer wet nappies than expected (under 6 wet nappies / day after day 5).
- Still jaundiced at 14 days (or 21 days if breastfed and otherwise thriving — but always worth checking).
- Dark urine + pale stools — possible biliary atresia (surgical emergency, time-sensitive).
How is bilirubin measured?
- Transcutaneous (TcB) — a non-invasive forehead or sternum measurement with a handheld light device. No needles. Used for screening. Underestimates at high values — confirmed with blood if near treatment threshold.
- Total serum bilirubin (TSB) — heelprick blood test, lab-measured. The gold standard. Used to make treatment decisions.
- Conjugated / direct bilirubin — a separate value. Should be < 1 mg/dL (17 μmol/L) or < 20% of total. Raised conjugated bilirubin = different pathway, not phototherapy.
What treatments are used and when?
Phototherapy — the first-line treatment
Blue light (425-475 nm wavelength — not UV) converts bilirubin in skin into water-soluble forms that the kidneys excrete without needing the liver pathway. Your baby goes under overhead lights or wrapped in a soft “bili blanket”, wearing just a nappy and eye pads. You can usually still feed and cuddle on breaks. Bilirubin drops 0.5-1 mg/dL/hour in the first few hours. Most babies need 24-48 hours total. Side effects: loose stools, mild dehydration (frequent feeds), occasionally a transient rash.
Intensive phototherapy
Higher light intensity by adding multiple light sources (e.g. overhead + bili blanket). Used when bilirubin is approaching the exchange threshold or rising fast.
IVIG (intravenous immunoglobulin)
Used for isoimmune haemolysis (Rh, ABO, anti-Kell incompatibility) to slow down the antibody-driven red-cell breakdown. Given alongside intensive phototherapy.
Exchange transfusion
NICU procedure when bilirubin is at exchange threshold and not responding. The baby’s blood is gradually replaced with donor blood over hours. Rare in modern practice (≤ 1 in 10,000 well term babies) but life-saving when indicated.
How to feed and care for a baby with jaundice
- Feed often — 8-12 times a day. Bilirubin gets reabsorbed from the gut if there’s not enough milk moving through. More feeds = more pees and poos = less bilirubin recycled. Single most important thing you can do.
- Wake baby for feeds if needed. Yes, even for a sleepy jaundiced baby. Tickle feet, undress, change nappy. A sleepy baby with poor intake gets MORE jaundiced.
- Track wet nappies — expect 1 wet/day on day 1, 2 on day 2, 3 on day 3, then 6+ from day 5 onwards.
- Check stools — meconium (dark green/black) by day 1, transitioning to yellow seedy by day 4-5. Stools that stay pale — URGENT same-day GP.
- Skin to skin when not under phototherapy — helps temperature, feeding, milk supply.
- Don’t use sunlight as treatment — risk of sunburn / dehydration; sunlight isn’t intense enough to safely treat clinical jaundice.
- Don’t give water or glucose water in the first weeks — reduces breast / formula intake, doesn’t help bilirubin.
- Skip the gripe water and herbal jaundice remedies — no evidence, possible harm.
Different scenarios — what you might see
Scenario 1: Day 3, full-term, jaundice to chest, bilirubin 12 mg/dL
Well below the AAP 2022 phototherapy line for a no-risk-factor full-term baby on day 3 (threshold ~17 mg/dL). Continue frequent feeding. Repeat bilirubin in 24 hours per local protocol. Likely no treatment needed.
Scenario 2: Day 2, 36 weeks, bilirubin 15 mg/dL, mum O+, baby A+
ABO incompatibility (risk factor). Lower threshold for treatment. Phototherapy likely indicated. Direct Coombs test to confirm haemolysis. Frequent feeding, monitor closely.
Scenario 3: Day 5, full-term breastfed baby, bilirubin 18 mg/dL, alert and feeding well
Likely classical breastfeeding-window peak. Around or above phototherapy threshold. Treatment for 24-48 hours expected. Breastfeeding continues throughout. Lactation support to ensure good intake. Recheck post-treatment.
Scenario 4: 3-week-old breastfed baby, mild jaundice still visible, gaining well, normal stools
Likely breastmilk jaundice. Continue breastfeeding. Routine prolonged-jaundice check: clinical exam, urine and stool colour, conjugated bilirubin (must be normal). Will resolve over 6-12 weeks.
Scenario 5: 2-week-old with pale stools, dark urine, persistent jaundice
Red-flag scenario. Could be biliary atresia — a surgical emergency where bile ducts haven’t formed properly. Outcomes are dramatically better if Kasai surgery is done by 60 days of life. Urgent specialist referral — not next week, today.
What changed in AAP 2022 vs 2004?
- Higher phototherapy thresholds — lines moved ~2 mg/dL higher across the board. Evidence showed the 2004 thresholds caused over-treatment with little additional benefit, and unnecessary maternal-baby separation.
- Race removed as a risk factor. The 2004 guideline used “East Asian race” as a risk factor lowering thresholds. Vyas et al. (NEJM 2020) showed this caused systematic under-treatment of darker-skinned babies and over-treatment of others. Race entirely removed in 2022.
- New escalation-of-care threshold — defined as 2 mg/dL below the exchange transfusion line. Prompts urgent NICU transfer for intensive phototherapy + possible exchange preparation.
- Cleaner gestational-age stratification — separate nomograms for 35, 36, 37, and 38+ weeks (vs the 2004 single “term” line).
- Universal pre-discharge screen — TcB or TSB on every baby before discharge.
Neurotoxicity risk factors — what lowers the treatment threshold
Any of the following lowers the AAP 2022 phototherapy threshold by ~2 mg/dL (because unbound bilirubin — the form that can cross into the brain — is more available):
- Isoimmune haemolytic disease — ABO, Rh, anti-Kell antibody.
- G6PD deficiency — common in Mediterranean, African, Middle Eastern, South Asian backgrounds.
- Sepsis — infection lowers albumin binding.
- Significant clinical instability — temperature, BP, acidosis.
- Significant lethargy.
- Low albumin (< 3.0 g/dL).
How to interpret the calculator result
- TSB well below threshold — routine care, recheck per local schedule.
- TSB 4-2 mg/dL below threshold — outpatient recheck likely in 12-24 hours.
- TSB 2 mg/dL below threshold — recheck earlier than planned (6-12 hours), counsel parents.
- TSB at or above phototherapy line — start phototherapy. Recheck TSB in 4-6 hours.
- TSB at or above escalation line — urgent NICU transfer, intensive phototherapy, prepare for possible exchange.
Limitations of this calculator
- This is a piecewise-linear approximation of the AAP 2022 nomogram curves — accurate to within ~0.5 mg/dL at band boundaries. For boundary cases, use the official AAP 2022 nomogram, BiliTool, or institutional protocol.
- Babies < 35 weeks gestational age follow the BAPM / NICE preterm pathway (lower thresholds).
- Conjugated bilirubin elevation (> 1 mg/dL or > 20% of total) is a SEPARATE pathway and indicates work-up for biliary atresia / sepsis / metabolic disease — NOT phototherapy.
- TcB underestimates TSB at higher values — confirm with serum bilirubin when near threshold.
- Educational only — doesn’t replace neonatal clinical judgement or institutional decision-support apps like BiliTool.
Sources
- Kemper AR, Newman TB, Slaughter JL, et al. Clinical Practice Guideline Revision: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation. Pediatrics 2022;150:e2022058859.
- Bhutani VK, Johnson L, Sivieri EM. Predictive ability of a predischarge hour-specific serum bilirubin. Pediatrics 1999;103:6-14.
- NICE. Jaundice in newborn babies under 28 days (CG98). 2010, updated 2016.
- Canadian Paediatric Society. Guidelines for detection, management and prevention of hyperbilirubinemia in term and late preterm newborn infants. 2024.
- Vyas DA, et al. Hidden in Plain Sight — Reconsidering the Use of Race Correction in Clinical Algorithms. N Engl J Med 2020.
- NHS UK. Newborn jaundice patient information.
Frequently asked questions
Why is my newborn yellow?
It's called jaundice — your baby's skin and the white of the eyes look yellow because of a substance called bilirubin building up. Bilirubin comes from the normal breakdown of red blood cells; in newborns it builds up because (1) they have lots of red cells from being in the womb that they don't need any more, and (2) their liver enzyme that gets rid of bilirubin is still ramping up. About 60% of full-term babies and 80% of premature babies show some jaundice. Most of it is harmless and goes away on its own.
When does newborn jaundice usually peak?
Bilirubin typically rises over the first 3-5 days of life, peaks around day 3-5, then falls. In a full-term baby, jaundice usually clears by 2 weeks. In a premature baby or breastmilk jaundice (see below), it can last 3-4 weeks. Jaundice that appears in the FIRST 24 HOURS of life is never normal — that's pathological and needs urgent bilirubin testing.
How do I know if my baby's jaundice is serious?
Worrying features (any of these): jaundice in the first 24 hours of life; bright yellow rather than slightly tan; yellow extending past the belly button down to the legs (use natural daylight, not lamps, to check); baby very sleepy / hard to wake / floppy / not feeding well / making fewer wet nappies; jaundice still there at 2 weeks (3 weeks if breastfed and otherwise well — but always worth checking). Don't rely on home apps to measure bilirubin — get a proper test (transcutaneous or blood).
What level of bilirubin is dangerous in a newborn?
It depends on the baby's exact age in HOURS (not just days) and their gestational age at birth. The thresholds change every few hours over the first few days. Roughly: for a healthy full-term baby (38+ weeks) with no risk factors, phototherapy is started somewhere around 12-15 mg/dL (200-260 μmol/L) on day 1, 15-18 mg/dL on day 2, 18-21 mg/dL on day 3+. For preterm or risk-factor babies, thresholds are 1-3 mg/dL lower. Use the calculator above with your baby's exact hours of life and bilirubin level for a precise answer.
What is phototherapy? Will it hurt my baby?
Phototherapy uses blue light to break down bilirubin in your baby's skin into water-soluble forms that the kidneys can excrete (without needing the liver's bilirubin pathway). It's NOT UV — doesn't tan, doesn't burn. Your baby goes either under overhead lights or wrapped in a soft 'bili blanket'. Eyes are covered with little pads. They usually wear just a nappy. Effective treatment drops bilirubin by 0.5-1 mg/dL per hour initially. Most babies need 24-48 hours of phototherapy. You can usually still cuddle and feed during breaks. Common side effects: loose stools, mild dehydration (needs frequent feeds), occasionally a transient rash.
Can I treat baby jaundice at home with sunlight?
NO. Even though sunlight does break down bilirubin, the risk of sunburn, dehydration, and temperature swings far outweighs any benefit. The amount of sunlight needed to treat clinical jaundice is also more than is safe for a newborn's skin. AAP, NHS, RCPCH all say don't use sunlight. If bilirubin is high enough to need treatment, you need proper phototherapy under medical supervision. If bilirubin is below treatment threshold, frequent feeding and time are what helps.
Does breastfeeding cause jaundice?
Two separate things both sometimes called 'breastfeeding jaundice'. (1) BREASTFEEDING FAILURE jaundice (first week): if breastfeeding isn't yet established and baby is getting too little milk, they get dehydrated, bilirubin goes back into the bloodstream through the gut (called enterohepatic circulation), and jaundice goes up. The fix is BETTER breastfeeding, not stopping it — frequent feeds (8-12/day), lactation support, latch check, possibly top-up expressed breastmilk if weight loss is significant. (2) BREASTMILK jaundice (weeks 2-12): a normal late jaundice pattern in well, thriving breastfed babies. Some substance in breast milk modestly slows bilirubin clearance. Completely benign. NEVER stop breastfeeding for this — just check there's no other cause.
Should I stop breastfeeding if my baby is jaundiced?
Almost never. If the jaundice is from breastfeeding failure (poor intake), the answer is MORE breastfeeding (and lactation support), not less. If it's breastmilk jaundice (late, well baby), breastfeeding is continued and the jaundice resolves on its own over weeks. Rare exceptions: occasionally a 24-48 hour pause is used diagnostically (jaundice drops sharply → confirms breastmilk jaundice). Decision is made by your neonatal team — never on your own.
What's a transcutaneous bilirubin (TcB) measurement?
TcB is a non-invasive forehead or sternum measurement using a handheld device that bounces light off the skin to estimate bilirubin. No needles. Used widely in postnatal wards and community midwifery for screening. Reliable at lower bilirubin levels but starts to underestimate at higher levels — AAP 2022 says confirm with a blood bilirubin (TSB) when TcB is within 2-3 mg/dL of the phototherapy threshold, or above 12-13 mg/dL. Most UK / EU / US units now screen with TcB and confirm with TSB only when decisions are being made.
What was wrong with the 2004 AAP guideline that the 2022 one fixed?
Two big issues. (1) Thresholds were too LOW — leading to over-treatment with little benefit and unnecessary maternal-baby separation. The 2022 thresholds are ~2 mg/dL higher across the board. (2) Race was used as a risk factor — 'East Asian race' lowered the threshold. Vyas et al. (NEJM 2020) showed this race-based rule caused UNDER-treatment of darker-skinned babies (where yellow is harder to see on physical exam) and over-treatment of others. The 2022 update removed race entirely and is what every US hospital now follows.
What is kernicterus and how do we prevent it?
Kernicterus is permanent brain damage from extremely high bilirubin levels (typically 25-30 mg/dL or higher) crossing the blood-brain barrier. Signs of early bilirubin encephalopathy: deep sleepiness, poor feeding, floppy → high-pitched cry, stiff body, arching backwards (opisthotonus) → seizures, breathing pauses. Long-term effects (chronic kernicterus): movement disorder (athetoid cerebral palsy), hearing loss, eye-movement problems, dental enamel issues. Extremely rare in countries with screening — UK rate around 1 in 100,000 babies. Prevention IS the AAP / NICE guidelines: universal pre-discharge bilirubin screening + timely phototherapy.
What is exchange transfusion?
A NICU procedure where the baby's blood is replaced (in small amounts at a time over hours) with donor blood through an umbilical or central catheter. It directly removes the bilirubin and any antibodies causing red-cell breakdown. Used when bilirubin is at or above the exchange threshold and intensive phototherapy isn't working fast enough, or when there are signs of brain involvement. Rare in modern practice (≤ 1 in 10,000 well term babies) because phototherapy + IVIG (for blood-group incompatibility cases) has reduced the need substantially. Life-saving when indicated.
Could there be a different cause for the jaundice?
Yes — bilirubin from red-cell breakdown (haemolysis) rather than just immature liver clearance. Causes: ABO blood-group incompatibility (mum O, baby A or B); Rh incompatibility (mum Rh-negative, baby Rh-positive — preventable with anti-D), other rare blood-group antibodies; G6PD deficiency (genetic enzyme deficiency, more common in some Mediterranean, African, Middle Eastern, South Asian backgrounds); spherocytosis; infection (sepsis). Conjugated hyperbilirubinaemia (raised 'direct' bilirubin) is a separate pathway — possible biliary atresia, sepsis, metabolic conditions — needs urgent specialist work-up.
Why are premature babies more likely to get jaundice?
Premature babies have: (1) more red cells to break down per kg of body weight; (2) immature liver enzymes even MORE underdeveloped than full-term; (3) lower albumin (the protein that mops up bilirubin); (4) more bowel sluggishness so bilirubin gets reabsorbed. All add up to higher and more prolonged jaundice. The treatment threshold is LOWER for preemies — AAP 2022 has separate nomograms for 35, 36, 37, and 38+ week babies. Babies under 35 weeks follow the BAPM / NICE preterm pathway.
What if my baby's jaundice is still there at 14 days?
Around 2-15% of well full-term breastfed babies have lingering jaundice ('prolonged jaundice') — usually breastmilk jaundice and benign. But always investigate at 14 days: clinical exam, urine and stool colour check (pale stools, dark urine = biliary atresia red flag), conjugated/'direct' bilirubin level (must be < 1 mg/dL or < 20% of total), and other targeted tests if indicated. NEVER assume prolonged jaundice is just breastmilk jaundice without ruling out biliary atresia — that's a surgical emergency if missed. NICE CG98 prolonged jaundice protocol applies.
Will jaundice affect my baby's brain development?
If bilirubin stays below the treatment thresholds (which AAP 2022 ensures with safety margins), the answer is NO — no measurable difference in development. Only sustained very-high bilirubin (typically > 25-30 mg/dL) carries the risk of brain damage. The whole point of screening + phototherapy is to prevent reaching those levels. Babies who get standard phototherapy and recover have normal long-term outcomes.
How can I tell jaundice from baby's normal skin tone?
Look in good NATURAL daylight (not under hospital lights, not under home lamps). Press a fingertip on the baby's skin until it blanches, then watch the skin colour return — jaundiced skin returns yellow. Jaundice spreads downwards (head first, then trunk, then arms/legs); jaundice past the belly button suggests bilirubin likely high enough to consider treatment. Also check the whites of the eyes (sclera) and inside the mouth (under the tongue). Don't rely on home photographs / smartphone apps — lighting variation makes them unreliable.
How does this relate to other calculators on BumpBites?
Companion: /calculators/apgar-score for newborn condition at birth; /calculators/newborn-diaper-output for the hydration check; /calculators/breastfeeding-latch if feeding-related jaundice suspected; /calculators/newt-weight-loss for weight-loss percentile; /calculators/baby-percentile for growth tracking; /calculators/eos-sepsis if infection in the differential.