Résumé
The advantage of weight loss in extreme preterm infants during the first days of life is discussed in the literature. The study aimed to assess the impact of weight loss during the first week on mortality and main morbidities of prematurity. Materials and methods: we retrospectively included preterm infants <27 weeks gestational age admitted to Neonatal Intensive Care Unit of Montpellier University Hospital from January 2012to December 2021. The optimal weight profile was defined by infants with weight loss between 5 and 15% of their birth weight during the first week of life (from D0 to D7). The primary endpoint was survival without severe morbidity. The relationship between the initial weight profile and its post-natal consequences was assessed by unadjusted and adjusted odds ratio (OR/aOR) on a propensity score with matching, derived from a logistic regression model based on perinatal data. Results: 245 infants were included, 112 had an optimal weight profile (45.7%). Survival without severe morbidity was similar, with 49/112 (43.7%) in the optimal weight profile group, and 32/133 (24.1%) in the non-optimal weight profile group, after adjustment [aOR 0.57 (0.30-1.11)]. aOR were comparable for severe morbidities and mortality, except for the BDP rate, which was significantly higher in the non-optimal weight profile group (41/90 (45.6%), compared with 21/88 (23.9%) in the optimal weight profile group [aOR 2.29 (1.06-4.94)].Conclusion: according to this cohort, weight loss of between 5 and 15% of birth weight of extreme preterm infants during the first week of life did not appear to influence survival without severe comorbidity rates in adjusted analyses. Further studies are needed to confirm this hypothesis, to better understand the determinants of this initial weight loss, and to define its optimal range.