Background: Neonatal hypocalcemia is defined when the total calcium levels are under 8 mg/dl (Ionic Ca < 1.1 mmol/l) in the full-term newborn, and under 7 mg/dl (Ionic Ca < 1 mmol/l) in the preterm. The fetus entirely depends on the maternal contributions of 25-OH-vitamin D, whose levels are directly correlated with diet and solar exposure. The largest transfer in calcium and vitamin D occurs in the third trimester of gestation, so prematurity is an important risk factor.
Objective: To evaluate the clinical characteristics of 11 neonates diagnosed with hypocalcemia due to maternal hypovitaminosis D in the last 3 years.
Method: Retrospective study of medical records. Statistical analysis with SPSS v.24.
Results: 11 patients: five females, six males. Gestational age: seven full-term and four preterm neonates. Discrete winter predominance (four cases). All appropriate for gestational age (AGE). Only two mothers received vitamin D supplements during pregnancy (200 UI per day). Feeding: seven formula feeding, four cases breastfeeding plus formula. Average age at diagnosis 3.8 days. Clinical presentation: three distal fine tremor; eight asymptomatic, diagnosed in blood test for another reason. All cases: total calcium at lower limit of normality, mean 7.2±0.5 mg/dl (average ionic Ca 0.99±0.05 mmol/l). 25-OH-vitamin D median 10 ng/ml (range 726 ng/ml), a case of insufficiency (2030 ng/ml) and 10 deficiencies (<20 ng/ml). PTHi median 52.4 pg/ml (range 6165 pg/ml) (normal value 1045 pg/ml). Maternal study: 25-OH-vitamin D mean 11, 1±4.5 mg/dl, deficiency in all cases. Treatment: four intravenous calcium (mean 6 days) and three oral calcium. Vitamin D supplements, doses of 800 IU/day in 10 cases and 400 UI/day in the patient with insufficiency. Ten patients in follow-up by pediatric endocrinology, six with normal values of 25-OH-vitamin D at 2 months, four patients at 5 months.
Discussion: Although current recommendations in our country only include maternal supplementation with iodine and folic acid during normal pregnancy, it may be necessary to modify them in the contribution of vitamin D, especially in regions of northern Spain where there is scarce solar exposure. It is important to consider that the effects of the vitamin D deficiency are extended far beyond the phospho-calcium metabolism. Longer studies are required. Many cases of neonatal hypocalcemia and hypovitaminosis course asymptomatically, so it could be an underdiagnosed entity.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology