Babies With Low Apgar Scores May Have Greater Cerebral Palsy Risk
Once a baby is born, one of the first things that occurs is the healthcare team assessing the infant’s condition using a scale called the Apgar score. Based on criteria such as complexion, pulse rate, reaction time, muscle tone, and breathing, a low score has been associated with cerebral palsy in childhood, according to new research published in BMJ.
The Apgar Score was devised in 1952 by Dr. Virginia Apgar, an anesthesiologist. The test is performed at one minute and five minutes after birth for all infants, but may be repeated later for infants who score low on the first two assessments.
Using data from the Medical Birth Registry of Norway and the Norwegian Registry of Cerebral Palsy in Children, researchers studied the five-minute Apgar scores of just over 543,000 children born between 1986 and 1995. A total of 988 of the children were diagnosed with cerebral palsy before the age of five years, a low Apgar score (less than 3) being strongly associated with the later diagnosis.
The association was found in both normal weight and low birth-weight babies.
Cerebral palsy is a rare neurological disorder that affects muscles and nerves of the body. About two to three infants in every 1000 children in Western countries are affected. There are several different types of cerebral palsy, including spastic, dyskinetic, ataxic, hypotonic, and mixed. Low Apgar score was associated with all subgroups of spastic cerebral palsy, which is characterized by tight muscles, abnormal walk, joint contracture, and paralysis of a group of muscles.
The Apgar score is calculated using the following criteria:
• Appearance: Skin color across the body and extremities should be pink, which leads to a score of 2. If the body is pink, but the extremities are blue, the infant receives a score of 1. If the baby is blue or pale all over, the score is 0.
• Pulse: A pulse rate of greater than or equal to 100 receives a score of 2. Pulse above 60 but below 100 receives a score of 1. Pulse rate below 60 receives a score of 0.
• Grimace (or Reflex Irritability): If the baby cries or pulls away when stimulated, the score is 2. If the cry is feeble, but the baby does respond, the score is 1. If the baby has no response to stimulation, score is 0.
• Activity (Muscle tone): A score of 2 means the baby has flexed arms and legs that resist extension. Score of 1 means the baby has some flexion, but if there is none, the score is 0.
• Respiration (breathing): A strong, lusty cry is desirable (2). If the breathing is weak, irregular or gasping, score is 1. If there is no respiration detected, score is 0.
A total is derived by adding together each of the 5 areas. Total Apgar score of 3 or below is generally regarded as critically low, 4 to 6 fairly low and 7 to 10 generally normal.
Although a low score is certainly cause for concern, Professor Nigel Paneth of Michigan State University, who wrote an accompanying editorial, said that most infants with such scores recover quickly and do well. Despite the strong association of low Apgar score with cerebral palsy, it is encouraging that almost 90% of children with an Apgar score of less than 4 at birth did not develop cerebral palsy.
Lie K, et al "Association of cerebral palsy with Apgar score in low and normal birthweight infants: population-based cohort study" BMJ 2010; DOI: 10.1136/bmj.c4990.
Paneth N "Apgar score and risk of cerebral palsy" BMJ 2010; DOI: 10.1136/bmj.c5175