Background: Late-onset neonatal sepsis (LONS) remains a major cause of morbidity in preterm neonates admitted to the neonatal intensive care unit (NICU), yet the contribution of vitamin D status to neonatal infectious susceptibility remains uncertain. Objective: To evaluate clinical and demographic variables and serum vitamin D levels assessed at birth in preterm neonates with and without LONS. Methods: A retrospective observational cohort study was conducted in a tertiary NICU in northeastern Mexico between May 2023 and October 2024. Preterm neonates (<37 weeks of gestation) with serum 25(OH)D measured within the first hour of life were included. Vitamin D status was classified as sufficient (≥30 ng/mL), insufficient (20–29 ng/mL), or deficient (<20 ng/mL). LONS was defined as sepsis occurring after 72 h of life. Comparisons between neonates with and without LONS were performed using Fisher’s exact test for categorical variables and Student’s t-test or Mann–Whitney U test for continuous variables, as appropriate. Results: Twenty-nine preterm neonates were included (mean gestational age: 32.0 ± 2.6 weeks; mean birth weight: 1748 ± 545 g). The mean serum 25(OH)D level at birth was 35.5 ± 13.0 ng/mL. LONS occurred in 31% (9/29) of neonates, of which 55% were microbiologically confirmed. No significant differences were observed in vitamin D levels between neonates with and without LONS (35.0 ± 12.0 vs. 35.7 ± 13.7 ng/mL; p = 0.899). Vitamin D deficiency was not associated with LONS (OR 1.13, 95% CI 0.09–14.28). The prevalence of vitamin D deficiency was low (10%) in this cohort. Conclusions: A clear association between serum 25(OH)D levels at birth and the development of LONS could not be demonstrated in this small exploratory cohort. Given the limited sample size and low prevalence of vitamin D deficiency, further multicenter prospective studies are required to better understand the potential relationship between vitamin D status and neonatal infectious outcomes.

Congenital heart disease (CHD) is the most common congenital malformation worldwide and remains a major cause of neonatal morbidity and mortality, particul

Background: Suboptimal growth velocity (GV)—weight < 15 g/kg/day, head circumference (HC) < 0.9 cm/week, and length < 1 cm/week—are related to neurodevelopmental problems. Comorbidities such as sepsis, patent ductus arteriosus, bronchopulmonary dysplasia, hemodynamic instability with use of inotropes, and necrotizing enterocolitis, among others, have been related to suboptimal GV. Therefore, this study aimed to evaluate GV in preterm newborns in the Neonatal Intensive Care Unit of a tertiary-level hospital in Mexico in the first 28 days of life and determine the main factors related to suboptimal GV. Methods: This was an observational, descriptive, retrospective, and longitudinal study. Thirty-one PNBs admitted to the NICU from March 2021 to February 2023 were included. Descriptive statistics were used for neonatal characteristics and factors. They were classified into group 1 (GV < 15 g/kg/day) and group 2 (>15 g/kg/day) and compared with Fisher’s exact test. Multivariate linear regression analysis was performed for factors related to suboptimal GV. Results: Among 31 preterm infants (mean GA 30 ± 3 weeks; birth weight 1241 ± 377 g), the mean growth velocity (GV) at 28 days was 16.5 ± 10 g/kg/day for weight (optimal), while length (0.7 ± 0.4 cm/week) and head circumference (0.41 ± 0.28 cm/week) remained suboptimal. Overall, 42% showed GV < 15 g/kg/day, and 58% achieved optimal GV. Multivariate analysis revealed that apnea of prematurity (β = –9.8; p = 0.023) and birth weight < 1000 g (β = –6.3; p = 0.026) were negatively associated with GV, whereas mixed feeding (breast milk + formula) had a positive effect (β = +6.3; p = 0.008). Conclusions: The 31 PNBs studied had a mean GV of optimal weight, and a mean GV of length and HC suboptimal to that suggested by the guidelines. The degree of low birth weight (LBW) and apnea of prematurity had a negative relationship with GV, while the type of feeding showed a positive relationship (p = 0.026, 0.023, and 0.008, respectively).

Background: Prematurity remains a major global health challenge and is a leading cause of neonatal morbidity and mortality worldwide. The risk of adverse outcomes is inversely associated with gestational age and birth weight. Although advances in neonatal intensive care have improved survival rates over recent decades, very-low-birth-weight (VLBW) preterm neonates continue to experience substantial morbidity and remain vulnerable to long-term complications. Objective: This study aimed to evaluate the morbidity and mortality of very-low-birth-weight preterm neonates (<1500 g) admitted to the Neonatal Intensive Care Unit (NICU) of the Hospital Regional de Alta Especialidad de Ciudad Victoria (HRAEV), Mexico. Materials and Methods: A retrospective observational cohort study was conducted through a review of medical records of VLBW preterm neonates admitted to the NICU between January 2019 and December 2023. Demographic, perinatal, clinical, and outcome-related data were collected and analyzed. Results: A total of 58 VLBW preterm neonates were included. Mean gestational age was 29.8 ± 2.7 weeks, and mean birth weight was 1109 ± 238 g. The most common morbidities were respiratory distress syndrome (81.0%), apnea of prematurity (72.4%), hyperbilirubinemia (68.9%), pneumonia (34.5%), sepsis (32.7%), patent ductus arteriosus (25.8%), bronchopulmonary dysplasia (26.9% among infants who survived to 36 weeks’ PMA), necrotizing enterocolitis (15.5%), and intraventricular hemorrhage (12.0%) and retinopathy of prematurity (8.6%). Overall mortality was 10.3%. Conclusions: VLBW preterm neonates remain at high risk for significant morbidity despite relatively favorable survival rates. Respiratory distress syndrome, apnea of prematurity, hyperbilirubinemia, and sepsis were the most frequent complications, whereas deaths occurred mainly in the context of severe respiratory and systemic complications, including neonatal asphyxia, pulmonary hypertension, sepsis, shock, and multiple organ failure. Survival outcomes should be interpreted cautiously because of differences in study populations, referral patterns, local viability practices, and study design across neonatal settings.