Evaluation of clinical and laboratory related factors of early-onset hypocalcemia in term neonates

Objective: Early-onset hypocalcemia (EOH) is a common metabolic disorder in neonates, which occurs during the first three days of life. The purpose of the study is to define the hypocalcemia characteristics, its clinical presentations, laboratory findings, and treatment for early-onset hypocalcemia in newborns. Method: This is a cross sectional study obtaining the patient’s data retrospectively from the Neonatal Intensive Care Unit at İzmir Buca Seyfi Demirsoy Training and Research Hospital. Fifty-one neonates born with ≥ 37 weeks of gestation who were diagnosed with hypocalcemia within the first three days of life between 2022-2024 were included in the study. The study analyzed demographic characteristics, laboratory values, timing and severity of hypocalcemia, treatment methods, and discharge details. Results: The study found no significant association between 25-OH vitamin D levels and birth weight or gestational age in neonates with EOH. Neonatal hypocalcemia onset on the 2nd and 3rd days of life showed higher initial calcium levels, suggesting early calcium levels may play a role. No significant association was found between 25-OH vitamin D levels and serum calcium, ionized calcium, or albumin levels, and hospitalization length. The use of calcium or vitamin D supplements did not influence 25-OH vitamin D levels or hypocalcemia outcomes. Conclusion: Gestational age and initial calcium levels are predictive of the timing and severity of EOH. However, 25-OH vitamin D levels were not significantly associated with birth weight, blood calcium, ionized calcium, or albumin levels in this population. These findings suggest that other factors influencing vitamin D metabolism in neonates with EOH require further investigation.