[Early hypophosphataemia in at risk newborns. Frequency and magnitude].

Objective: To determine the frequency and magnitude of neonatal hypophosphataemia (<4mg/dL) in a neonatal Intensive Care Unit and to describe risk groups.
Patients and Methods: Retrospective study of hospitalised newborns over a 44 month period (phase 1). Retrospective study of <1,500g/<32 weeks of gestation newborns over a 6 month period (phase 2). Prospective study of <1,500g or 1,550-2,000g, and intrauterine growth restriction (IUGR) newborns. Measurements were made on the 1st, 3rd, 7th, and 14th days of life (phase 3).
Results: Phase 1: 34 (2.4%) of 1,394 patients had a diagnosis of hypophosphataemia, 76% of them ≤32 weeks of gestation and <1500 grams, and 24% >32 weeks with weight<P10. Phase 2: 12 (16.4%) of 73 patients had a diagnosis of hypophosphataemia, with <2mg/dL in 5 (6.8%). Eight (75%) of those with hypophosphataemia had IUGR, and 4 (25%) weighed <1,000g. Five cases had associated hypokalaemia, and three hypercalcaemia. Phase 3: 9 (45%) of 20 patients had hypophosphataemia, all of them <1,000g or<1,200g and weight percentile <10. Thirty-three percent of samples on days 1, 3, and 7 showed hypophosphataemia, four of them <2mg/dL. There was mild hypokalaemia in 5 (55%), and mild hypercalcaemia in 2 (22%) cases. Hypophosphataemia was associated with lower enteral nutrition and higher parenteral amino acid intake in the early days of life.
Conclusions: Hypophosphataemia is common, and can be severe, in the first week of life in premature infants <1,000 grams, and newborns<1,200g with foetal malnutrition and receiving amino acids in early parenteral nutrition.
(Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.)