Late-onset neonatal hypocalcemia in a 9-days-old baby because of vitamin D deficiency and hypoparathyroidism a case report

ABSTRACT Background: Neonatal hypocalcemia is a metabolic abnormality commonly reported. Late onset hypocalcemia usually manifests after 7 days and requires a long-term therapy. Neonatal hypocalcemia due to hypoparathyroidism can manifest as life-threatening seizures or tetany. Initial management is important to prevent any complication due to this condition. However, the initial management to correct hypocalcemia with the administration of calcitriol, high dose intravenous and oral calcium may take longer to achieve because of hypoparathyroidism. Case summary: We report a case of late onset neonatal hypocalcemia in a nine-days-old baby. He was born on the 35-36 week of gestational age by Caesarean section, without asphyxia nor neonatal infection. The baby had a refractory seizure with low serum calcium and magnesium, high phosphate, normal alkaline phosphatase (ALP) and low calcium creatinine urine ratio. His 25-hidroxy vitamin D (25-OHD) total was as low as 12.9 ng/mL. And, he has a low level of parathyroid hormone (PTH). Adequate correction for hypocalcemia and hypomagnesemia failed to maintain calcium and magnesium to their normal value. Oral calcium gluconolactate and carbonate were added after calcitriol supplementation, but seizure still noticed. After magnesium oxide supplementation was given, another seizure had never occurred. A long-term follow-up on vitamin D and calcium level were required. Conclusion: In a hypocalcemic newborn patient, assessment of the magnesium, vitamin D, and PTH status are needed. Keywords: neonatal, hypocalcemia, parathyroid, vitamin D Cite This Article: Arimbawa, I., Utami, D., Suryawan, I. 2016. Late-onset neonatal hypocalcemia in a 9-days-old baby because of vitamin D deficiency and hypoparathyroidism: a case report. Bali Medical Journal 5(3): 208-213. DOI:10.15562/bmj.v5i3.355 INTRODUCTION Electrolyte imbalance occurs frequently in neonates. One of the essential electrolytes is calcium. Calcium ion is crucial for many biochemical processes including blood coagulation, neuromuscular excitability, cell membrane integrity, and many of the cellular enzymatic activities. A major part of the body calcium exists in bones and muscles (99%) and the rest of the calcium is present in the extracellular fluid (1%). Around 40% of calcium binds with albumin and becomes crystal with anion phosphorus and therefore becomes inactive. But, 50% exists in a free ionized form. Healthy term infants undergo a physiological lowest point in serum calcium by 24-48 hours of age. The nadir may drop to hypocalcemic level in high-risk neonates, for example in the infants of diabetic mothers, preterm infants, and infants with perinatal asphyxia.1-3 Neonatal hypocalcemia is classified into early onset hypocalcemia which presents within 72 hours after birth and requires treatment with calcium supplementation for at least 72 hours. In contrast, late onset hypocalcemia usually presents after 7 days and requires long-term therapy.4 Hypocalcemia is an uncommon problem in term and near-term neonates. A study showed a significant increase in urinary calcium to creatinine ratio and fractional excretion of sodium in full-term neonates who were treated with gentamicin (2.5 mg/kg of body weight every 12 hours). These changes were not seen in infants who received amikacin or netilmicin. Birth asphyxia is associated with lower serum calcium level in the newborn period. Other factors such as increased bicarbonate therapy, phosphate loads, and functional hypoparathyroidism are possible pathogenetic mechanisms for the hypocalcemia.2 Neonatal hypocalcemia due to hypoparathyroidism is rare and may manifest as life-threatening seizures or tetany. The initial management is by administering calcitriol and high dose calcium. But hypocalcemia correction in hypoparathyroidism using intravenous and oral calcium takes longer to achieve. The use of recombinant parathyroid hormone to correct hypocalcemia due to hypoparathyroidism has been proposed, but still lacking supporting evidence.4-8 A proper handling of late-onset neonatal hypocalcemia will have a good outcome. CASE PRESENTATION March 25, 2016 A 2900 gram, preterm male neonate with gestation age 35-36 week was born to a gravida 2 mother by a Caesarean section. He had a normal extra-uterine transition (Apgar score was 8 and 9 at the 1st and