Growth phenotypes of very low birth weight infants for prediction of neonatal outcomes from a Brazilian cohort: comparison with INTERGROWTH.

OBJECTIVE: To assess the predictive value of selected growth phenotypes for neonatal morbidity and mortality in preterm infants < 30 weeks and to compare them with INTERGROWTH-21st (IG21). METHOD: Retrospective analysis of data from the Brazilian Neonatal Research Network (BNRN) database for very low birth weight (VLBW) at 20 public tertiary-care university hospitals. OUTCOME: the composite neonatal morbidity and mortality (CNMM) consisted of in-hospital death, oxygen use at 36 weeks, intraventricular hemorrhage grade 3 or 4, and Bell stage 2 or 3 necrotizing enterocolitis. Selected growth phenotypes: small-for-gestational-age (SGA) defined as being < 3rd (SGA3) or 10th (SGA10) percentiles of BW, and large-for-gestational-age (LGA) as being > 97th percentile of BW. Stunting as being < 3rd percentile of the length and wasting as being < 3rd percentile of BMI. Single and multiple log-binomial regression models were fitted to estimate the relative risks of CNMM, comparing them to IG21. RESULTS: 4,072 infants were included. The adjusted relative risks of CNMM associated with selected growth phenotypes were (BNRN/IG21): 1.45 (0.92-2.31)/1.60 (1.27-2.02) for SGA; 0.90 (0.55-1.47)/1.05 (0.55-1.99) for LGA; 1.65 (1.08-2.51)/1.58 (1.28-1.96) for stunting; and 1.48 (1.02-2.17) for wasting. Agreement between the two references was variable. The growth phenotypes had good specificity (>95%) and positive predictive value (70-90%), with poor sensitivity and low negative predictive value. CONCLUSION: The BNRN phenotypes at birth differed markedly from the IG21 standard and showed poor accuracy in predicting adverse neonatal outcomes.

Sequential changes of longitudinal and radial myocardial deformation indices in the healthy neonate heart.

BACKGROUND: Significant hemodynamic changes, including preload and afterload modifications, occur during the transition from the fetal to the neonatal environment. The ductus arteriosus closes, pulmonary vascular resistance decreases, and pulmonary blood flow increases. Strain rate (SR) and strain (epsilon) have been proposed as ultrasound indices for quantifying regional wall deformation. This study was designed to determine if these indices can detect variations in regional deformation between early and late neonatal periods. METHODS: Data were obtained from 30 healthy neonates (15 male). The initial study was performed at a mean age of 20.1+/-14 hours (exam 1) and the second at 31.9+/-2.9 days (exam 2). Apical and parasternal views were used to quantify regional left ventricular (LV) and right ventricular (RV) longitudinal and radial SR and epsilon, and systolic, early, and late diastolic values were calculated from these curves. A paired-samples t test was performed comparing the two groups. RESULTS: Compared with exam 1, LV radial deformation showed significant reductions in peak systolic epsilon in the basal and mid segments (51+/-15% vs 46+/-9%, P<.01). LV longitudinal deformation behaved similarly, showing significant peak systolic epsilon reductions in all measured segments. Systolic SR showed reductions only in the basal and apical segments of the lateral wall and in the mid portion of the inferior wall (-1.9+/-0.5 vs -1.7+/-0.3 s(-1) and -1.9+/-0.4 vs -1.7+/-0.2 s(-1), respectively, P=.03). RV longitudinal free and inferior wall systolic SR and epsilon values were significantly higher in exam 2. CONCLUSIONS: LV peak systolic epsilon decreases in exam 2 were possibly due to afterload increase and preload decrease. The lower RV initial deformation indices could be attributed to increased afterload caused by physiologic pulmonary hypertension or immature RV contractile properties. SR seemed to be a more robust index than epsilon and less influenced by preload and afterload hemodynamic alteration.