Apgar Score Calculator
Calculate the Apgar score for newborn assessment at 1, 5, and 10 minutes after birth. Evaluates appearance, pulse, grimace, activity, and respiration.
SNAP-II / SNAPPE-II Score Calculator
Calculate SNAP-II and SNAPPE-II neonatal illness-severity scores using the worst values from the first 12 hours after NICU admission.
⚠️ Medical Disclaimer: SNAP-II/SNAPPE-II scores predict neonatal mortality risk based on physiological data from the first 12 hours of NICU admission. They are used for risk stratification and benchmarking, not for individual treatment decisions. Always apply clinical judgment.
Perinatal Extension (PE) Items:
SNAP-II Physiology (first 12h):
°C
mmHg
mL/kg/h
▼
SNAPPE-II Score
8
Low Risk
Approximate cohort mortality context: <1%
Birth Weight
8
5-min Apgar
0
SGA Status
0
Temperature
0
Lowest BP
0
PO₂/FiO₂
0
Lowest pH
0
Seizures
0
Urine Output
0
SNAP-II (Physiology)
0
SNAPPE-II (Severity+Ext.)
8
SNAPPE-II Score⧉
8
Low Risk
SNAP-II Score⧉
0
Physiological severity alone
Mortality Context⧉
<1%
Approximate cohort-based context from derivation data, not an individual treatment rule
Highest Contributor⧉
Birth Weight
8 points
Active Factors⧉
1 / 9
Number of contributing risk factors
Perinatal Extension⧉
8 pts
Birth weight + Apgar + SGA contribution
| SNAPPE-II | Risk | Mortality | Interpretation |
|---|---|---|---|
| 0-9 | Low | <1% | Lower illness-severity cohort |
| 10-19 | Low-Moderate | 1-5% | Meaningful physiologic derangement is present |
| 20-29 | Moderate | 5-15% | Higher illness-severity group in benchmarking studies |
| 30-39 | Moderate-High | 15-30% | Substantial first-12-hour instability |
| 40-55 | High | 30-60% | Very high severity in derivation cohorts |
| >55 | Very High | >60% | Extreme cohort-level severity; not a stand-alone care directive |
| Variable | Threshold | Max Points |
|---|---|---|
| Birth weight | <750 g | 38 |
| Lowest BP | <20 mmHg | 19 |
| Multiple seizures | Present | 19 |
| Urine output | <0.1 mL/kg/h | 18 |
| 5-min Apgar | 0-3 | 17 |
| PO₂/FiO₂ ratio | <0.3 | 16 |
| Lowest pH | <7.10 | 16 |
| SGA status | <3rd percentile | 12 |
| Temperature | <35.6°C | 8 |
Planning notes, formulas, and examples
About the SNAP-II / SNAPPE-II Score Calculator
The Score for Neonatal Acute Physiology (SNAP-II) and its Perinatal Extension (SNAPPE-II) are neonatal illness-severity scores based on the worst values from the first 12 hours after NICU admission. SNAP-II uses physiologic variables, while SNAPPE-II adds birth weight, 5-minute Apgar score, and small-for-gestational-age status.
These scores are most useful for neonatal illness-severity stratification, benchmarking, and research-style risk adjustment. Higher scores generally indicate greater early illness severity and a higher cohort-level mortality risk.
The page should be read as a prognostic and benchmarking aid, not as a treatment algorithm or a goals-of-care rule for an individual infant.
When This Page Helps
A structured severity score helps summarize how unstable a neonate was during the first critical hours after admission. That can be useful for documentation, benchmarking, and understanding overall illness burden.
The page is most appropriate when used as a standardized severity summary rather than as a stand-alone management directive.
How to Use the Inputs
- Use the worst physiologic values recorded during the first 12 hours after NICU admission.
- Enter the perinatal extension items: birth weight, 5-minute Apgar score, and SGA status.
- Review the SNAP-II and SNAPPE-II totals.
- Interpret the score as illness-severity and cohort-risk context rather than an individual treatment rule.
Formula used
SNAP-II uses 6 physiologic variables from the first 12 hours after NICU admission.
SNAPPE-II = SNAP-II + perinatal extension items:
- Birth weight
- 5-minute Apgar score
- Small-for-gestational-age statusExample Calculation
Result: SNAP-II 22, SNAPPE-II 62
The score reflects substantial early physiologic instability plus high perinatal-risk contribution from extreme prematurity. The main use of that result is neonatal severity stratification and outcome context, not a stand-alone treatment directive.
Tips & Best Practices
- Use the worst values in the first 12 hours, not averages.
- Review SNAP-II and SNAPPE-II together so you can separate physiologic instability from perinatal-risk contribution.
- Treat mortality percentages as cohort context, not as a stand-alone bedside prediction.
- Do not use the score by itself to drive treatment limitation decisions.
- Keep the derivation window explicit whenever the score is documented.
- Use the score for severity framing and benchmarking, not as a complete neonatal care pathway.
Why These Scores Matter
SNAP-II and SNAPPE-II help summarize neonatal illness severity early in the NICU course using a common framework. That makes them useful for comparing populations and describing how sick an infant was at presentation.
What They Do Not Replace
They do not replace bedside neonatal assessment, diagnostic reasoning, or individualized treatment planning. A high score does not tell the team what to do next by itself.
Best Use
Use the page to standardize early illness-severity documentation and to frame cohort-level mortality context cautiously.
Sources & Methodology
Last updated:
Methodology
This page calculates SNAP-II and SNAPPE-II from the worst values recorded during the first 12 hours after NICU admission. SNAP-II summarizes physiologic instability, and SNAPPE-II adds the original perinatal extension items such as birth weight, 5-minute Apgar score, and small-for-gestational-age status.
The output is meant for neonatal illness-severity framing, benchmarking, and cohort-level mortality context. It should not be used as a stand-alone treatment algorithm, futility rule, or withdrawal-of-care trigger for an individual infant.
Sources
- SNAP-II and SNAPPE-II: Simplified newborn illness severity and mortality risk scores (Journal of Pediatrics) — Original derivation paper for SNAP-II and SNAPPE-II.
Frequently Asked Questions
It is based on the worst values from the first 12 hours after NICU admission, so it is most appropriate once that observation window is complete.
It is used for neonatal illness-severity stratification, benchmarking, and research-style risk adjustment. It is not a therapy algorithm by itself.
No. A high score reflects greater early illness severity and higher cohort-level risk, but it should not be used as a stand-alone futility or goals-of-care rule for an individual infant.
Very preterm infants often have high SNAPPE-II scores partly because the perinatal extension strongly weights birth weight. That is why the physiologic SNAP-II component is still useful to review separately.
The page follows the score’s small-for-gestational-age item rather than a general-purpose growth-screening rule. It should be interpreted with the neonatal growth reference used in practice.
No. They are cohort-derived approximations from the score literature and should be read as severity context rather than exact individual calibration.
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