Preterm neonates are at high risk of infectious and inflammatory diseases which require antibiotic treatment. Antibiotics influence neonatal gut microbiome development, and intestinal dysbiosis has been associated with delayed gastrointestinal transit. Neonates who take less time to pass meconium have a better tolerance to enteral feeding. We analyzed the effect of neonatal antibiotic treatment on the stool pattern and oral tolerance in 106 preterm infants < 33 weeks gestational age. Neonates were classified in 3 groups according to neonatal antibiotic (ABT) treatment days: no antibiotics, 3–7 d ABT, and ≥8 d ABT. Preterm infants from the ≥8 d ABT group took longer to pass meconium and to start green and yellow stools, took longer to reach 100 and 150 mL/kg/day, and reached reduced volumes in enteral feeds at day of life 14 and 28 than infants from no ABT and 3–7 d ABT groups. Multiple linear regression models showed that neonatal antibiotic treatment, birth weight, invasive mechanical ventilation, surfactant, enteral feeding start day, neonatal parenteral nutrition, and neonatal fasting days are associated with the stool pattern and oral tolerance in preterm infants.

Background/Objectives: Overweight and obesity during pregnancy are metabolic risk factors that may compromise offspring brain development. The first 1000 days of life represent a critical window in which neurodevelopmental trajectories are shaped by intrauterine and early-life exposures. The 6- and 12-month milestones are key checkpoints where deviations may emerge, and interventions are most effective. This study evaluated the association between maternal pregestational weight status and infant neurodevelopment at 6 and 12 months of age. Methods: Mother and infant pairs from the OBESO perinatal cohort in Mexico City were included. Women in the first trimester of pregnancy were classified as normal weight and overweight/obesity according to their pregestational body mass index (pBMI), calculated from self-reported pre-pregnancy weight. Infant neurodevelopment was assessed at 6 and 12 months using the Bayley Scales of Infant Development III, Third Edition (BSID-III). Descriptive, bivariate and multiple linear regression analyses with mixed effects correction were conducted. Results: Among 97 mother–infant pairs, infants of mothers with overweight/obesity had lower language and socio-emotional scores at 12 months. Higher maternal pBMI was correlated with lower motor scores at 6 and 12 months, and with lower language scores at 12 months. Longitudinal analysis showed that maternal overweight/obesity was associated with a significant decline in language development from 6 to 12 months. (p = 0.002). Conclusions: Maternal pregestational overweight or obesity may negatively influence early neurodevelopment, particularly affecting language and cognitive domains during the first year of life. These early deficits could reflect alterations in intrauterine programming associated with maternal metabolic status.

Prenatal exposure to air pollution is a major public health concern due to its potential to impair fetal brain development. This study examined whether maternal inflammatory and oxidative stress biomarkers mediate the association between trimester-specific air pollutant exposure during pregnancy and infant neurodevelopment at one year. We analyzed 87 mother–infant pairs from the OBESO perinatal cohort in Mexico City. Trimester-specific exposure to CO, PM₁₀, PM_2.5, SO₂, and O₃ was estimated using residential geolocation. Biomarkers were measured in the first and third trimesters by protocol, and intra-pregnancy change was calculated as Δ(3T–1T) for cytokines (IL-1β, IL-6, TNFα) and oxidative stress markers (malondialdehyde (MDA), protein carbonyls (PC), and total antioxidant capacity (TAC). Infant neurodevelopment at 12 months was assessed using Bayley-III. Exploratory mediation analyses were conducted, adjusting for gestational age at birth, pre-eclampsia, gestational diabetes, fetal growth restriction, marital status, mode of delivery, and infant sex; bootstrapping was applied to obtain robust estimates. Third-trimester CO exposure was associated with poorer receptive language (coef = 0.754, p = 0.02). PM_2.5 exposure showed direct effects on expressive language in the first (coef = 0.01, p = 0.04) and third trimesters (coef = 0.007, p = 0.015) in models including IL-1β. Third-trimester O₃ and SO₂ exposures were linked to lower expressive scores in models including TNFα (coef = 0.007, p = 0.02), MDA (coef = 0.008, p = 0.04), and PC (coef = 0.007, 95% p = 0.04). Meanwhile PM₁₀ exposure was associated with socio-emotional outcomes in models with IL-6 and TAC (coef = 0.003, p = 0.04). These findings indicate that maternal inflammation and oxidative stress biomarkers did not mediate the associations between prenatal air pollution exposure and infant neurodevelopment, and this study cannot elucidate their specific biological role in neurodevelopment.

Background: COVID-19 has become a threat to global public health. However, severe forms of COVID-19 presentation in children are rare. We present the case of an infant with COVID 19-related multisystem inflammatory syndrome. Case report: We describe the case of an 8-month-old infant who had contact with COVID-19 positive adults. The infant began with mild symptoms of the disease but rapidly progressed to a critical form of presentation: initially with epileptic status, and upon admission with laboratory evidence of inflammation, severe systemic condition with multiple organ failure, and a positive nasopharyngeal SARS-CoV-2 PCR test. The infant died 7 days after admission. Conclusions: The spectrum of COVID-19 presentation in children under one year of age is variable, and there are still no established criteria for diagnosis and treatment. All infants presenting a severe disease with multiple organ involvement at admission in times of pandemic require a thorough medical history to consider SARS- CoV-2 infection until proven otherwise.