Perinatal Risk Factors for Early Onset Hypocalcemia in Moderate-to-Late Preterm Infants

Abstract

Objective: Early onset neonatal hypocalcemia (ENH) occurs within 72 hours after birth and screening is recommended for high-risk infants. This study aimed to analyze the risk factors predictive of ENH and evaluate the effectiveness of intervention for ENH in moderate-to-late preterm infants. Methods: This was a retrospective study, examining moderate-to-late preterm infants at 32-36 weeks of gestational age. Perinatal factors were compared between infants with and without hypocalcemia. Related factors were further analyzed to evaluate the validity of the predictive factors for ENH. The effect of intervention was analyzed by comparing changes in serum calcium levels on day 3 and day 7. Results: A total of 112 infants were enrolled. There were 65 infants in the non-hypocalcemic group and 47 in the hypocalcemic group. Between the two groups, only lower magnesium levels on day 1 were related to ENH with an odds ratio of 0.247 using a cutoff value of 1.7 mmol/L for hypocalcemia (sensitivity 42.6%, specificity 80.0%, P=0.005). No infant with hypocalcemia exhibited clinical seizures. Intervention was performed with oral calcium supplements or low-phosphorus milk feeding in 30 infants. The intervention was more effective in resolving hypocalcemia than no intervention (n=17). Conclusion: Lower magnesium levels on day 1 were related to lower calcium levels and a 4-fold higher risk for hypocalcemia. Moderate-to-late preterm infants with hypomagnesemia should be closely monitored for ENH. Additionally, interventions were found to be effective in restoring calcium levels in ENH.