For years, obstetricians and hospitals have tried to deflect attention from their mistakes by claiming that negligence during labor and delivery — like prolonged labor where a baby is deprived of oxygen, or where the delivery is traumatic — can’t cause cerebral palsy. I’ve written before about the problems with the American College of Obstetricians and Gynecologists’ guidelines on “Neonatal Encephalopathy and Cerebral Palsy.” Now there’s a new study of over a million births confirming that a lack of oxygen during birth is by far the most common cause of cerebral palsy.

On March 7, 2017, the Journal of the American Medical Association published the results of a study of over 1.4 million births in Sweden. The purpose of the study was to look for any connection between overweight or obese mothers and cerebral palsy. The authors found a link, but, as they say, “the effect of maternal obesity on cerebral palsy” was “small compared with other risk factors.”

So what really causes cerebral palsy? The biggest culprit is a lack of oxygen. As the medical researchers found,

  • Hypoxic-ischemic encephalopathy made cerebral palsy 108 times more likely.
  • Extreme prematurity (22-27 weeks) made cerebral palsy 57 times more likely.
  • Very preterm birth (28-31 weeks) made cerebral palsy 31 times more likely.
  • Meconium aspiration made cerebral palsy 15 times more likely.
  • Neonatal infection made cerebral palsy 9 times more likely.
  • Traumatic delivery made cerebral palsy twice as likely.

(Read more about the connection between hypoxia and cerebral palsy here.)

The study also confirmed the conditions the best predictors for when a child will have cerebral palsy: neonatal seizures and low Apgar scores.

  • If a baby had seizures after birth, they were 119 times more likely to be diagnosed with cerebral palsy.
  • If a baby had an Apgar score of 0-3 after 5 minutes, they were 65 times more likely to have cerebral palsy.
  • If a baby had an Apgar score of 4-6 after 5 minutes, they were 19 times more likely to have cerebral palsy.

The authors tried to explain this result away as “a matter of debate”:

More than 70% of cerebral palsy cases occur in children born at full term … The relative contribution of asphyxia to the etiology of cerebral palsy is a matter of debate. In a review of 23 studies, the proportion of cerebral palsy cases with asphyxia varied from 3% to 56%, probably due to differences in operational definitions of asphyxia, cerebral palsy, or both; small sample sizes; and selection problems. The conditions commonly used to define asphyxia, including hypoxic ischemic encephalopathy, seizures, and low Apgar score, are not necessarily specific for fetal hypoxia, but could be the result of other pathologies including chorioamnionitis, stroke, or inflammation.

But there’s no denying what their own data found. And conditions like “chorioamnionitis, stroke, or inflammation” are themselves reasons for doctors to change what they’re doing and protect the mother and the baby, such as through an emergency c-section.

It’s good to see more scientific analysis of the causes of cerebral palsy. It would be even better if medical researchers could see what the evidence is telling them: medical malpractice, like preventable hypoxia, causes thousands of children every year to develop cerebral palsy.