What is the purpose and interpretation of the Apgar (Appearance, Pulse, Grimace, Activity, Respiration) score in newborns?

Apgar Score: Purpose and Interpretation

The Apgar score is a standardized tool for assessing a newborn's physiologic condition immediately after birth at 1 and 5 minutes (and beyond if needed), primarily to guide resuscitation needs rather than predict long-term outcomes. 1

Primary Purpose

The Apgar score evaluates five physiologic signs—Appearance (color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), and Respiration—to determine the infant's immediate condition and need for resuscitation. 2 This scoring system provides a standardized method for reporting the newborn's status and response to any resuscitative interventions. 3

Timing and Scoring

• Assess at 1 minute and 5 minutes after birth as standard practice. 1
• If the 5-minute score is ≤5, continue scoring every 5 minutes up to 20 minutes. 1
• Each of the five components receives 0,1, or 2 points, with a maximum total score of 10. 2
• Use an expanded Apgar score reporting form that documents concurrent resuscitative interventions, as scores assigned during active resuscitation differ from those in spontaneously breathing infants. 1, 3

Clinical Interpretation for Immediate Management

1-Minute Score

• A 1-minute score of 0-3 does NOT predict individual infant outcomes and should only guide immediate resuscitation decisions. 1
• The 1-minute score identifies which infants require cardiopulmonary resuscitation. 4

5-Minute Score

• A 5-minute score ≤5 mandates NICU admission, umbilical arterial blood gas sampling, and consideration of placental pathology examination. 5
• A 5-minute score of 0-3 correlates with neonatal mortality in populations but does not predict individual neurologic dysfunction. 1
• Scores of 7-10 at 5 minutes, when associated with normal fetal heart rate tracings and normal umbilical cord arterial pH, generally indicate good immediate condition. 5

Extended Scoring (10,15,20 Minutes)

• An Apgar score ≤3 at 10,15, or 20 minutes indicates progressively increasing population risk of poor neurologic outcomes. 1
• At 20 minutes, a score of 0-3 carries extremely high mortality (59%) and morbidity (57% cerebral palsy in survivors). 5

Relationship to Long-Term Outcomes

What the Score Does NOT Do

• The Apgar score alone cannot be considered evidence of asphyxia. 1, 3
• It does not predict individual mortality or adverse neurologic outcomes. 1
• Most infants with low Apgar scores will NOT develop cerebral palsy. 1

Population-Level Risk Assessment

• A low 5-minute score (0-3) confers a 20- to 100-fold increased relative risk of cerebral palsy compared to scores of 7-10, though absolute risk remains low. 1, 5
• Scores <5 at both 5 and 10 minutes clearly increase relative risk of cerebral palsy, with degree of abnormality correlating with risk magnitude. 1, 5
• The association between low scores and increased risks of death, cerebral palsy, epilepsy, and cognitive impairment is consistent across studies, but absolute risks remain <5% for most neurologic conditions. 6

Critical Limitations and Pitfalls

Factors That Influence the Score

• Gestational age, maternal medications (sedation/anesthesia), congenital malformations, trauma, and interobserver variability all affect scoring. 1
• Subjective components (tone, color, reflex irritability) depend partially on physiologic maturity. 1
• Normal transitional variations exist—target oxygen saturations are 60-65% at 1 minute and 80-85% at 5 minutes per Neonatal Resuscitation Program guidelines. 1

Common Pitfalls to Avoid

• Never use the Apgar score in isolation to diagnose intrapartum hypoxic-ischemic events. 1
• Always integrate multiple factors: fetal heart rate monitoring patterns, umbilical arterial blood gas results, clinical cerebral function, neuroimaging, neonatal EEG, placental pathology, and multisystem organ dysfunction. 1
• The score is insensitive for predicting long-term neurologic handicap and lacks sensitivity/specificity for reflecting degree of acidosis. 2
• In high-risk low-birthweight infants, the predictive value for mortality is limited compared to normal-birthweight infants. 2

Practical Clinical Algorithm

When 5-minute Apgar score is ≤5:

1. Admit to NICU immediately. 5
2. Obtain umbilical arterial blood gas from clamped cord section. 1, 5
3. Submit placenta for pathologic examination. 1
4. Continue Apgar scoring every 5 minutes until score >5 or 20 minutes reached. 1

When 5-minute Apgar score is 6:

• Clinical judgment required based on overall clinical picture and trajectory from 1-minute score. 1

When 5-minute Apgar score is 7-10:

• Generally reassuring if accompanied by normal fetal heart rate tracing and normal umbilical cord arterial pH. 5

Quality Improvement Applications

Monitor trends in low Apgar scores at the delivery service level to identify needs for focused educational programs and improvements in perinatal care systems. 1 Analyzing these trends allows assessment of quality improvement intervention effectiveness. 1