Neonatal Hypoglycemia Exposure Not Associated with Lower Academic Achievement

Christopher J. D. McKinlay, PhD

Recent findings from a cohort study of infants born at risk of hypoglycemia suggested that exposure to neonatal hypoglycemia compared to no exposure was not significantly associated with lower educational achievement in mid-childhood.

Moreover, each cohort did not significantly differ on rates of low educational achievement, while children exposed to hypoglycemia were significantly less likely to be rated by teachers as being below or well below the curriculum level for reading.

“While exposure to hypoglycemia may alter the shape of the early developmental course, this study suggests that at-risk children reach similar end points by the end of primary schooling,” wrote study author Christopher J. D. McKinlay, PhD, Liggins Institute, University of Auckland.

The longitudinal cohort study included infants born at or after 32 weeks’ gestation recruited to 2 neonatal studies conducted from December 2006 - November 2010 at Waikato Women’s Hospital in Hamilton, New Zealand.

Eligibility included infants born with at least 1 risk factor for neonatal hypoglycemia, such as mother with diabetes, preterm (<37 weeks), small (<10th percentile or <2500 g), or large (>90th percentile or <4500 g).

Masked continuous glucose monitoring was performed for up to 7 days. A hypoglycemic episode was defined as at least 1 consecutive blood glucose concentration less than 47 mg/dL and an interstitial episode as a sensor glucose concentration less than 47 mg/dL for at least 10 minutes.

At 9 and 10 years, children underwent in-depth assessment by trained assessors, who targeted 5 key domains including academic achievement, executive function, visual-motor function, psychosocial adaptation, and general health. The primary outcome was categorized as low educational achievement, performing below or well below the normative curriculum level in standardized tests of reading comprehension or mathematics.

From 587 eligible children (n = 230 female [48%]), 480 (82%) were assessed at a mean age of 9.4 years. Investigators observed neonatal hypoglycemia occurred in 304 children (63%), of whom 111 (37%) had at least 1 severe event and 165 (54%) had recurrent events (198 [65%] had severe or recurrent hypoglycemia).

Data show exposure to neonatal hypoglycemia compared with no exposure was not significantly associated with low educational achievement (138/296 [47%] versus 82/172 [48%]; adjusted risk difference -2% [95% CI, -11% to 8%]; adjusted risk ratio, 0.95 [95% CI, 0.78 - 1.15]).

Then, children who were exposed to neonatal hypoglycemia compared to those who are not, were significantly less likely to be rated by teachers as being below or well below the curriculum level for reading (68/281 [24%] versus 49/157 [31%]; adjusted risk difference, -9% [95% CI, -17% to -1%]; adjusted risk ratio, 0.72 [95% CI, 0.53 - 0.99; P = .04)]).

However, there were no significant differences between exposure groups in any other secondary outcomes, including low achievement in reading comprehension or mathematics z scores, learning support, and teacher-rated educational performance.

The team noted it is unlikely that the findings are unique to the current cohort, due to high rates of neurodevelopmental impairment observed in other cohorts of infants born at risk of transitional neonatal hypoglycemia.

“Therefore, efforts to prevent and optimize adverse pregnancy conditions remain important, and developmental surveillance after birth should be considered for at-risk infants,” McKinlay concluded.

The study, “Association of Neonatal Hypoglycemia With Academic Performance in Mid-Childhood,” was published in JAMA.