Hypoglycemia in unmonitored full-term newborns-a surveillance study

Fitness of INTERGROWTH-21st birth weight standards for Chinese-ethnicity babies

OBJECTIVE

To determine the fitness of the INTERGROWTH-21st birth weight standards (INTERGROWTH21) for ethnic Chinese babies compared with a local reference (FOK2003).

DESIGN

Population-based analysis of territory-wide birth data.

SETTING

All public hospitals in Hong Kong.

PARTICIPANTS

Live births between 24 and 42 complete weeks' gestation during 2006-2017.

MAIN OUTCOME MEASURES

Babies' birth weight Z-scores were calculated using published methods. The two references were compared in three aspects: (1) the proportions of large-for-gestational-age (LGA) or small-for-gestational-age (SGA) infants, (2) the gestation-specific and sex-specific mean birth weight Z-scores and (3) the predictive power for SGA-related complications.

RESULTS

488 896 infants were included. Using INTERGROWTH21, among neonates born <33 weeks' gestation, the mean birth weight Z-scores per week were closer to zero (-0.2 to 0.05), while most of them were further from zero (0.06 to 0.34) after excluding infants with a high risk of abnormal intrauterine growth. Compared with FOK2003, INTERGROWTH21 classified smaller proportions of infants as SGA (8.3% vs 9.6%) and LGA (6.6% vs 7.9%), especially SGA among preterm infants (13.1% vs 17.0%). The area under the receiver operating characteristic curve for predicting SGA-related complications was greater with FOK2003 (0.674, 95% CI 0.670 to 0.677) than INTERGROWTH21 (0.658, 95% CI 0.655 to 0.661) (p<0.001).

CONCLUSIONS

INTERGROWTH21 performed less well than FOK2003, a local reference for ethnic Chinese babies, especially in infants born <33 weeks' gestation. Although the differences are clinically small, both these references performed poorly for extremely preterm infants, and thus a more robust chart based on a larger sample of appropriately selected infants is needed.

A case of severe neonatal transient hyperinsulinemic hypoglycaemia without identifiable risk factors: a case report

Background

Neonatal hypoglycaemia is one of the major metabolic disorders that causes irreversible brain injury. Assessing for maternal glucose metabolism disorders can predict and avoid this perinatal complication. Accordingly, diagnosing maternal gestational diabetes mellitus (GDM) is important in protecting neonatal neurological prognosis. However, there are various methods of screening for maternal GDM. The intervention for neonatal hypoglycaemia also varies within each guideline.

Case presentation

A female infant was born at 37 weeks of gestation by vaginal delivery with no asphyxia. Her mother had no abnormal findings, including glucose metabolism disorders, upon periodic prenatal visits. Upon routine examination at the first hour of life, the baby was lethargic, pale, hypotonic, and rarely cried. An emergent systemic evaluation was performed, and she was diagnosed with severe hyperinsulinemic hypoglycaemia with blood glucose of 11 mg/dL and insulin of 2.7 µU/mL. She was soon fed with milk and her symptoms of hypoglycaemia was resolved before receiving intravenous glucose infusion. Her blood glucose level reached 78 mg/dL 3 h after delivery. She was discharged home with her mother on day 6 of age without relapse of hypoglycaemia. Upon review, we determined that the mother was diagnosed with GDM during her previous pregnancy but not during this current pregnancy. The infant had no developmental delay upon check-up at 6 months.

Conclusions

The infant of this case was not a candidate for neonatal hypoglycaemia screening since her mother had no identifiable risk factors. This case suggests that previous maternal history of GDM might be the cause of neonatal hyperinsulinemic hypoglycaemia. Clinicians need to be aware of the possibility of hypoglycaemia among newborns with a maternal previous history of GDM, regardless of the mother’s current diagnosis. Immediate oral feeding can be one of the treatments, even for symptomatic neonatal severe hypoglycaemia, when rapid intravenous access is difficult. The present case also suggests the necessity of considering neonatal outcomes as well as maternal ones when screening for maternal disorders of glucose metabolism.