Outcomes of neonatal hypothermia among very low birth weight infants: a Meta-analysis

Neonatal admission hypothermia (HT) is a frequently encountered problem in neonatal intensive care units (NICUs) and it has been linked to a higher risk of mortality and morbidity. However, there is a disparity in data in the existing literature regarding the prevalence and outcomes associated with HT in very low birth weight (VLBW) infants. This review aimed to provide further summary and analyses of the association between HT and adverse clinical outcomes in VLBW infants.

In July 2020, we conducted this review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic database search was conducted in MEDLINE (PubMed), Google Scholar, ScienceDirect, World Health Organization Virtual Health Library, Cochrane Library databases, and System for Information on Grey Literature in Europe (SIGLE). We included studies that assessed the prevalence of HT and/or the association between HT and any adverse outcomes in VLBW infants. We calculated the pooled prevalence and Odds Ratio (OR) estimates with the corresponding 95% Confidence Interval (CI) using the Comprehensive meta-analysis software version 3.3 (Biostat, Engle-wood, NJ, USA; http://www.Meta-Analysis.com ).

Eighteen studies that fulfilled the eligibility criteria were meta-analyzed. The pooled prevalence of HT among VLBW infants was 48.3% (95% CI, 42.0-54.7%). HT in VLBW infants was significantly associated with mortality (OR = 1.89; 1.72-2.09), intra-ventricular hemorrhage (OR = 1.86; 1.09-3.14), bronchopulmonary dysplasia (OR = 1.28; 1.16-1.40), neonatal sepsis (OR = 1.47; 1.09-2.49), and retinopathy of prematurity (OR = 1.45; 1.28-1.72).

Neonatal HT rate is high in VLBW infants and it is a risk factor for mortality and morbidity in VLBW infants. This review provides a comprehensive view of the prevalence and outcomes of HT in VLBW infants.