018 - Copeptin in cord blood: A marker of urinary concentration capacity in premature infants?

Publication Number: 18.4213

Astrid C. Viennet, Universite de Montreal Faculty of Medicine, PARIS, Ile-de-France, France; Anik Cloutier, CHU Sainte-Justine, Montreal, PQ, Canada; Adrien Flahault, Université de Lorraine, Vandoeuvre les Nancy, Lorraine, France; Mi-Suk Kang Dufour, University of montreal, Montreal, PQ, Canada; Rafael Oliveira. Fernandes, Universite de Montreal Faculty of Medicine, Montreal, PQ, Canada; Daniela Ravizzoni Dartora, CHU Sainte Justine, Montreal, PQ, Canada; Pierre-Emmanuel Girault Sotias, Universite de Montreal Faculty of Medicine, Montreal, PQ, Canada; Coraline De Sousa Do Outeiro, Research center - CHU Sainte-Justine, Montreal, PQ, Canada; Maily Fradette, Universite de Sherbrooke Faculty of Medicine, Boucherville, PQ, Canada; Sandrine Wavrant, sainte Justine Hospital, université de Montréal, montreal, PQ, Canada; Thuy Mai Luu, Centre Hospitalier Universitaire Sainte-Justine, Montreal, PQ, Canada; Anne-Monique Nuyt, Universite de Montreal Faculty of Medicine, Montreal, PQ, Canada

Background:

Background: Due to renal immaturity, water-sodium (WS) imbalance is a major issue in the management of newborn preterm infants, which can lead to neurological and respiratory complications and even death. Vasopressin (AVP) is involved in fine WS regulation in older children, but its contribution in the first days of life is less known.

Objective:

Objective: The aim of this study was to assess the renal response to AVP in preterm infants to determine whether its measurement at the cord could guide the clinician in the WS management of the preterm newborn.

Design/Methods: METHODS: This single-center prospective cohort conducted at Sainte-Justine Hospital, Montreal, Canada, included a group of preterm infants ( < 37 weeks gestation - wks) and a group of term controls. Cord plasma copeptin, a stable biomarker of AVP, and osmolality were measured at birth, as well as natremia between day (D) 1 and D3 and urinary osmolality at D1.

Results:

Results: 112 neonates were included (76 preterm). The median gestational age was 32.0wks (+/- 2.9wks) in preterm group and 38.6wks (+/- 1.0wk) in full-term group. The mean birth weight was 1592g (+/- 546g) corresponding to 38th percentile in preterm group and 3395g (+/- 493g) corresponding to 57th percentile in full-term group. The median cord copeptin value was similar in both groups (p=0.448), and statistically higher in cases of vaginal or emergency caesarean delivery (p < 0.001). There was no association between cord copeptin and plasma osmolality in all neonates (R²=0.11, p=0.237). Because few term infants had measured natremia, further analyses were conducted only on preterm group: there was no association between cord copeptin and urine osmolality at D1 (R²=0.04, p=0.764) and no association between cord copeptin and natremia variations (DeltaMaxNa+) in the three first days of life (R²=-0.01, p=0.795).

Conclusion(s):

Conclusion: In preterm infants, there was no association between AVP at birth and urinary osmolality at D1. This indicates that AVP has no effect on WS regulation in the first days of life in this population. Further studies are needed to explore mechanisms of WS imbalance in preterm infants. Whether similar renal insensitivity to AVP early in life is present in term infants is probable but remains to be demonstrated.