Novel Characterization of the Incidence and Risk Factors for Neonatal Hypoglycemia in the Premature Infant <33 Weeks

Student Researcher:
Nikki Mitchell

Supervisor / Principle Investigator:
Dr. Georg Schmölzer

MD Class of 2020


Objective: To determine incidence and risk factors associated with neonatal hypoglycemia in the premature population <33 weeks gestational age.

Methods: Retrospective analysis of 175 infants <33 weeks gestational age enrolled in the Sustained Inflation Study were combined with maternal demographics from chart review. Hypoglycemia (blood glucose <2.6mmol/L) determined via glucose oxidase method on cord blood gas was stratified into mild (2.2-2.6mmol/L), severe (1.1-2.2mmol/L), and extreme (<1.1mmol/L). Birth weight subgroups included small for gestational age (SGA, birth weight <10%ile for gestational age) and large for gestational age (LGA, birth weight >97%ile for gestational age). Maternal hypertension was systolic blood pressure >140mmHg, and maternal obesity was body mass index >35.

Results: Hypoglycemia occurred in 59 infants (33.7%) [mild n=16 (9.1%), severe n=34 (19.4%), extreme n=9 (5.1%)]. Risk factors for hypoglycemia included SGA or LGA infants (OR 6.34, 95% CI 2.00-24.10, p=0.003), and maternal hypertension (OR 3.07 , 95% CI 1.51-6.30, p=0.002). Protective factors for hypoglycemia included in labour at time of delivery (OR 4.51, 95% CI 2.29-9.18, p <0.0001), and antenatal magnesium sulphate (OR 2.53, 95% CI 1.23-5.50, p = 0.01). There was no significant difference between hypoglycemic and euglycemic infants in sex (OR 0.92, 95% CI 0.49-1.73, p=0.79), gestational age (OR 1.09, 95% CI 0.96-1.24, P=0.18), antenatal steroids (OR 0.67, 95% CI 0.31-1.41, p=0.30), vaginal birth (OR 2.17, 95% CI 0.96-5.43, p=0.08), maternal obesity (OR 0.59, 95% CI 0.31-1.12, p=0.11), or maternal diabetes (OR 0.66, 95% CI 0.31-1.47, p=0.30). Risk factor analysis between severity levels of hypoglycemia was not completed due to small sample size in some subgroups.

Conclusion: Premature infants <33 weeks are at increased risk of hypoglycemia. SGA or LGA infants and maternal hypertension increase hypoglycemia risk. Antenatal magnesium sulphate administration or labour at time of delivery decrease hypoglycemia risk.