In the study, McKinlay’s team followed 477 infants who were born between December 2006 and November 2010. About half of the babies were diagnosed with low blood sugar at birth and treated. Most of those in the study received continued monitoring of the blood sugars; some infants whose low blood sugar was not detected at birth turned out to have it later.
At a follow-up at the age of about 4.5 years, the researchers found that low blood sugar levels were linked with certain brain function difficulties. However, the study only found an association and couldn’t prove a cause-and-effect relationship.
For the study, low blood sugar was defined as at least one episode of blood sugar concentration less than 47 milligrams per deciliter (mg/dL), a severe episode with blood sugar under 36 mg/dL, or recurrent (three or more) hypoglycemic episodes.
The important finding is that the effects of low blood sugar in newborns may show up later, said Dr. Saima Aftab, medical director of the Fetal Care Center at Nicklaus Children’s Hospital in Miami. She reviewed the study findings but was not involved in the research.
McKinlay tells parents to be aware of the risk factors for low blood sugar, and be sure your newborn has blood glucose measured. If the values are low, he said, ask for that test to be confirmed. He recommends asking for it be confirmed by a lab glucose test rather than a bedside strip meter test.
Aftab tells parents to pay close attention if the pediatrician tells you that your newborn has low blood sugar. “As a parent, you know you have to work very closely with your pediatrician to make sure your child is reaching developmental milestones at the right time,” she said.
Blood glucose “is fuel for the brain,” she explained. It’s crucial to help the brain grow and develop, especially in the newborn periods, when numerous connections are being made.
The study was published online Aug. 7 in JAMA Pediatrics.
Visit the U.S. National Institutes of Health for more on newborn low blood sugar.