Reasoning GP · Algorithm · 1-page summary
Neonatal jaundice
For: babies birth to 28 days with suspected jaundice, prolonged jaundice, or still jaundiced at the 6–8-week check. Not for: babies under neonatal-team care (follow their plan).
Core rule: always measure bilirubin (TcB or serum) and plot it on the NICE CG98 chart for gestation and age in hours — never judge by eye. Jaundice in the first 24 hours is pathological, and pale stools or dark urine mean biliary atresia until excluded.
0Stop — call 999 now — before any measurement
- Signs of bilirubin encephalopathy: high-pitched cry, arching, extreme lethargy or hard to rouse, hypotonia, poor feeding, seizures, hyperthermia → 999
- Sick or shocked jaundiced neonate (sepsis until proven otherwise), altered consciousness, collapse, respiratory or cardiovascular compromise → 999
- Jaundice in the first 24 hours and unwell, unstable, neurological signs or unsafe to transfer → 999
- Not in primary care: phototherapy, exchange transfusion, cultures, IV antibiotics.
1Triage by age at onset — postnatal age in hours and days
| Onset | Action |
|---|---|
| <24 hours | Pathological until assessed → Urgent hospital serum bilirubin within 2 h, medical review within 6 h |
| Day 2–14 | Physiological most likely, but measure and plot: it is a diagnosis of exclusion. |
| >14 d (>21 d if <37 wk) | Prolonged → split bilirubin and NICE work-up (block 3) |
| 6–8-week check | Still jaundiced → split bilirubin + stool card. Never wait for it. |
2Screen — one row is enough
- Pale, chalky or clay stools (card colours 1–3), however mild the jaundice → Same-day paediatrics, phoned directly.
- Dark urine staining the nappy, or conjugated bilirubin >25 μmol/L → paediatric or hepatology advice Same-day
- SBR at/above phototherapy line, rise >8.5 μmol/L/h or haemolysis → Same-day neonatal; above exchange line → Urgent hospital
- Temperature ≥38°C or <36°C → Paediatrics within 2 h; unwell → 999
- Weight loss >10%, poor urine or stool output, ineffective feeding or dehydration → feeding and neonatal assessment Same-day
- Galactosaemia (not screened): vomiting, hepatomegaly, hypoglycaemia, E. coli sepsis → phone the metabolic team now Emergency; feeds changed only on their advice.
3Assess — only once blocks 0–2 are answered
☐ Gestation, age in hours, feeding, weight, stool and urine colour, maternal blood group ☐ Alertness, tone, sclerae, gums, blanched skin (harder in darker skin), liver and spleen, bruising ☐ TcB if ≥35 weeks and >24 h, otherwise SBR; SBR if TcB >250 μmol/L or at threshold, and always after phototherapy
Prolonged: ☐ conjugated bilirubin ☐ FBC ☐ mother's and baby's blood group + DAT ☐ urine culture only if UTI suspected ☐ bloodspot result (congenital hypothyroidism) documented
Not: Kramer zones instead of a number, a percentage conjugated threshold, or a liver panel unless advised.
4Classify — only if the screen is negative
- Physiological — appears day 2–3, peaks day 3–5, gone by day 10–14; well, feeding, yellow or green stools, below threshold.
- Breast milk jaundice — well, thriving, breastfed, beyond 14 days; needs a normal split bilirubin first.
- Haemolytic (Rh, ABO, G6PD, spherocytosis) — onset <24 h, rapid rise → neonatal team (block 1).
- Conjugated — dark urine, pale stools: biliary atresia, hepatitis, metabolic → same-day specialist (block 2).
- Hypothyroidism or UTI — prolonged unconjugated; check the bloodspot; suspected UTI → Same-day paediatrics
- Uncertain — measure and plot again; never label it physiological without a number.
5Treat today — only these
- Well, ≥38 weeks, below threshold: >50 μmol/L below → usually no routine repeat. Within 50 → repeat within 18 h with risk factors, otherwise 24 h, via the local midwifery or neonatal pathway.
- Feeding: continue breastfeeding; never stop it for jaundice. Supplement (expressed breast milk first) only if weight loss >10% or inadequate intake is confirmed.
- No phototherapy outside the neonatal service, and no sunlight as treatment.
- No discharge without a review plan and escalation level.
6Refer routinely
- Prolonged jaundice, well, normal stools and urine, conjugated not raised → paediatric review per the local pathway.
- Feeding difficulty → same-day breastfeeding support (midwife, infant feeding team, National Breastfeeding Helpline 0300 100 0212).
- Bloodspot result missing → contact the local newborn screening team promptly.
- After severe jaundice → specialist hearing and development follow-up.
7Never reassure by
- How yellow the skin looks — always measure.
- "Breast milk jaundice" without a split bilirubin.
- A baby who looks well but has pale stools or dark urine.
- The 6-week check still to come.
- A fixed bilirubin level — plot it for gestation and age in hours.
- A TcB reading after phototherapy.
8Safety-net — say it, give it in writing, document it
999 “Call 999 if your baby is hard to wake or floppy, has a high-pitched cry, arches their back or has a fit.” Same day: “Contact us today if the poo turns pale, white or chalky, the wee is dark and stains the nappy, the yellow deepens or spreads to the palms and soles, or feeding gets worse. Check the poo colour at every nappy change.” Temperature ≥38°C or <36°C → seen within 2 hours.
Remote or OOH: jaundice cannot be judged without a TcB or serum bilirubin — convert to face-to-face; deepening jaundice or parental concern → same-day assessment.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
Bilirubin measured and plotted; split bilirubin if prolonged
Feeding effective; weight, stools and urine checked
Repeat measurement or review booked, with owner
Written safety-net given; bloodspot result confirmed
Summary of the full Reasoning GP neonatal jaundice algorithm, which holds the detail and evidence. Sources: NICE CG98 (updated 2023) and threshold charts; CLDF Yellow Alert; BAPS-CASS; NHS Newborn Bloodspot Screening; BAPM. Clinical reference — follow local neonatal pathways; use the NICE CG98 charts for all treatment decisions.