A low Apgar score is any score below 7 out of a possible 10, measured at 1 and 5 minutes after birth. The American College of Obstetricians and Gynecologists (ACOG) breaks it down further: a score of 4 to 6 is moderately abnormal, and a score of 0 to 3 is critically low. Most babies score 7 or above at the 5-minute mark, which is considered reassuring.
What the Apgar Score Measures
The Apgar score evaluates five signs of a newborn’s physical condition, each worth 0, 1, or 2 points:
- Heart rate: No heartbeat scores 0. Under 100 beats per minute scores 1. Over 100 scores 2.
- Breathing: No breathing scores 0. Slow, irregular, or gasping breaths score 1. Strong crying scores 2.
- Muscle tone: Limp and floppy scores 0. Some bending of the arms and legs scores 1. Active movement that resists being straightened scores 2.
- Reflex response: No reaction to stimulation scores 0. A grimace scores 1. Crying, coughing, or sneezing scores 2.
- Skin color: Pale or blue all over scores 0. Pink body with bluish hands and feet scores 1. Entirely pink scores 2.
The name doubles as a handy acronym: Appearance, Pulse, Grimace, Activity, Respiration. Dr. Virginia Apgar, an anesthesiologist, created the system in the early 1950s after noticing that newborns received very little structured medical attention in the moments after delivery. According to medical lore, she first sketched the scoring system on a cafeteria napkin when a resident asked what he should be checking. Her goal was a quick, standardized way to flag babies who needed immediate help.
Why the 5-Minute Score Matters More
Your baby is scored at both 1 minute and 5 minutes after birth. The 1-minute score was originally designed to flag whether a baby needs immediate help with breathing or circulation. The 5-minute score, however, is a much stronger indicator of how the baby is doing overall. Research from a large Canadian study found that a low score at 5 minutes was more strongly linked to later developmental concerns than a low score at 1 minute alone.
If the 5-minute score is still low, the medical team will continue scoring every 5 minutes, up to 20 minutes after birth. A score that stays at 0 for 10 minutes or longer carries the most serious implications. Very few infants with a 10-minute score of 0 survive with a normal neurological outcome, and clinical guidelines consider this a point where the care team may discuss whether to continue resuscitation efforts.
The trend matters as much as any single number. A baby who scores 3 at 1 minute but climbs to 7 by 5 minutes is in a very different situation than one whose score remains at 3. A score that drops between time points also raises concern and prompts the team to look for underlying issues like a congenital condition or breathing difficulty.
Common Reasons for a Low Score
More than a third of low Apgar scores are attributed to oxygen deprivation during labor or delivery. When a baby doesn’t get enough oxygen in the womb, the heart rate, breathing, and muscle tone all suffer, dragging multiple components of the score down at once. Several specific factors increase the risk:
- Prolonged labor: Labor lasting more than 24 hours is one of the strongest predictors, linked to roughly 11 times the odds of a low 5-minute score in one study.
- Abnormal fetal heart rate: A heart rate that is too slow or too fast before delivery signals that the baby is under stress. Slow heart rate alone was associated with about 9 times the odds of a low score.
- Meconium in the amniotic fluid: When a baby passes stool before birth, it can block the airway or signal distress. This roughly triples the risk of a low 5-minute score.
- Low birth weight and prematurity: Smaller, earlier babies have about 4 times the odds of scoring low, largely because their lungs and circulatory systems aren’t fully developed.
- Type of anesthesia: Certain medications given to the mother during delivery can temporarily depress the baby’s nervous system, lowering muscle tone and reflexes.
Infection, congenital abnormalities, and complications of cesarean delivery can also play a role. In many cases, the cause is temporary and the baby responds quickly to basic support like warming, drying, and gentle stimulation.
What a Low Score Does and Doesn’t Predict
A low Apgar score is not a diagnosis. ACOG is explicit on this point: the score alone should not be used to predict whether any individual baby will have long-term neurological problems. It was designed as a quick snapshot of how a newborn is transitioning to life outside the womb, not as a forecast of future health.
That said, population-level research does show real statistical associations. A 5-minute score below 7 is linked to a 20- to 100-fold increased relative risk of cerebral palsy compared to babies who score 7 to 10. The risk of epilepsy roughly doubles, and the risk of being diagnosed with a neurological disability is about four times higher. A threefold increase in the risk of autism has also been reported. These numbers sound alarming, but context matters: the absolute risk of conditions like cerebral palsy is very small to begin with. Most babies with low Apgar scores do not develop cerebral palsy or any lasting neurological condition.
The effect on cognitive ability is modest. Large studies following over 170,000 individuals found that a 5-minute score below 7 was associated with an average IQ decrease of only 1.2 to 1.8 points, a difference too small to notice in everyday life. Babies whose scores were low only briefly (recovering before the 5-minute mark) showed virtually no association with later cognitive performance.
Limitations for Premature Babies
The Apgar score was developed for full-term newborns, and it doesn’t translate cleanly to premature infants. A baby born at 28 weeks will almost always have weaker muscle tone, slower reflexes, and less vigorous breathing than a full-term baby, simply because of immaturity rather than illness. This means premature babies routinely score lower even when they’re doing as well as expected for their gestational age.
There’s also an inherent subjectivity problem. Scoring often happens while the medical team is actively helping the baby breathe, making it hard to separate the baby’s own efforts from the support being provided. In some cases, scores are assigned after the fact, during or after a hectic resuscitation. Because of these issues, a joint statement from the American Academy of Pediatrics and ACOG recommends that Apgar scores in preterm infants not be used for any purpose beyond guiding immediate care in the delivery room.
What Happens When a Score Is Low
The Apgar score itself doesn’t dictate what the medical team does. Resuscitation decisions are based on real-time observation of the baby’s breathing, heart rate, and color, not on waiting for a formal score to be tallied. In practice, though, the interventions a baby receives map closely to the problems the score reflects. A baby who isn’t breathing may be gently stimulated, have their airway cleared, or receive supplemental oxygen. A baby with a very slow or absent heartbeat may need chest compressions or additional support.
For most babies with moderately low scores (4 to 6), basic warming, drying, and stimulation are enough to bring the score up within minutes. Babies with critically low scores (0 to 3) need more intensive help. The medical team will continue reassessing every 5 minutes to track whether the baby is responding. A rising score is a good sign and is the most common trajectory, even for babies who start out with very low numbers.