Background: Chorioamnionitis is a recognized risk factor of preterm delivery; however, controversy still persists concerning the relationship between maternal inflammation and neonatal morbidity and mortality. Objective: To determine the incidence of clinical chorioamnionitis and its relationship to morbidity and mortality among very-low-birth-weight (VLBW) infants. Methods: This was a retrospective analysis of prospectively collected data of VLBW neonates ≤32 weeks' gestational age (GA) admitted to collaborating units in the Spanish SEN1500 Network between January 2008 and December 2011. Clinical chorioamnionitis was defined by obstetricians based on clinical findings, and neonatal outcomes were compared between exposed and non-exposed infants by multivariate logistic regression analysis. Results: During the study period, 11,464 VLBW newborns were admitted to our units and 10,026 were ≤32 weeks' GA. Among them, 8,330 (83.1%) had complete data and were included. Of these, 1,480 (17.8%) were exposed to maternal clinical chorioamnionitis. The incidence was higher at lower GA and, after adjusting for confounding factors, exposed infants had higher risks of early-onset neonatal sepsis (EONS) (10.0 vs. 2.8%; aOR 3.102; 95% CI 2.306-4.173; p < 0.001) and necrotizing enterocolitis (NEC) (11.2 vs. 7.7%; aOR 1.300; 95% CI 1.021-1.655; p < 0.033), but lower risks of patent ductus arteriosus (PDA) (43.2 vs. 34.9%; aOR 0.831; 95% CI 0.711-0.971; p < 0.02) and late-onset bacterial sepsis (LONS) (36.6 vs. 32.5%; aOR 0.849; 95% CI 0.729-0.989; p < 0.035). There were no differences in mortality between the groups. Conclusions: The incidence of maternal clinical chorioamnionitis is inversely related to GA at delivery, and in VLBW infants ≤32 weeks' GA it is associated with higher risks of EONS and NEC, but lower risks of PDA and LONS. We did not found differences in survival.

Background: Advances in perinatal care can influence morbidity and mortality in newborns at the limit of viability. Knowledge of these changes over time may help improve clinical decision making, optimize resource allocation and increase quality of care. Objectives: To evaluate the influence on morbidity and mortality of changes introduced in the perinatal care of preterm infants (22-26 weeks' gestational age, GA) in Spain between two consecutive periods (2002-2006 and 2007-2011). Methods: An analysis of prospectively collected data in a national database network (SEN1500) was performed. All live newborn infants of 22-26 weeks' GA born in or transferred to referral centers of the SEN1500 network in the first 28 days of life were included. Perinatal interventions, clinical management, neonatal morbidity, and survival until hospital discharge were retrieved. Results: A total of 5,470 newborns were included (2,533 and 2,937 in each period, respectively). The major changes introduced during the second period were as follows: (1) lower proportion of extramural births (11.0 vs. 8.9%, p = 0.01), (2) increase in antenatal steroids (69.5 vs. 80.8%, p < 0.001), (3) delivery by C-section (41.8 vs. 48.3%, p < 0.001) and (4) use of CPAP during resuscitation (7.8 vs. 20.7%, p < 0.001). Death in the delivery room decreased from 5.1 to 3.2% (p < 0.001). Survival increased from 49.9 to 57.9% (p < 0.001), and survival without major morbidity increased from 18.1 to 21.2% (p = 0.006). Conclusions: During the second period, a greater attachment to practices proven to have a beneficial impact on survival and reduction of morbidity in the extremely preterm infant was noted, and survival and survival without major morbidity increased. A more conservative approach was detected for newborns of 22 weeks' GA.

Objective: To evaluate trends in respiratory care practices and bronchopulmonary dysplasia (BPD) among very preterm infants born in Spain between 2010 and 2019. Study design: This was a retrospective cohort study of data obtained from a national population-based database (SEN1500 network). Changes in respiratory care and BPD-free survival of infants with gestational age (GA) of 23⁰–31⁶ weeks and <1500 g were assessed over two 5-year periods. Temporal trends were examined by joinpoint and Poisson regression models and expressed as the annual per cent change and adjusted relative risk (RR) for the change per year. Results: A total of 17 952 infants were included. In the second period, infants were less frequently intubated in the delivery room and during neonatal intensive care unit stay. This corresponded with an increase in use of non-invasive ventilation techniques. There were no significant differences between the periods in BPD-free survival or survival without moderate-to-severe BPD. After adjusting for covariates, the RR for the change per year was significant for the following variables: never intubated (RR 1.03, 95% CI 1.02 to 1.04); intubation in the delivery room (RR 0.98, 95% CI 0.97 to 0.99); use of nasal intermittent positive pressure ventilation (RR 1.08, 95% CI 1.05 to 1.11); and BPD-free survival (only in the group with the lowest GA; RR 0.98, 95% CI 0.97 to 0.99). Conclusion: Our findings reveal significant changes in respiratory care practices between 2009 and 2019. Despite an increase in use of non-invasive respiratory strategies, BPD-free survival did not improve and even worsened in the group with the lowest GA (23⁰–25⁶).

Background: Extrauterine growth restriction is common in the preterm infant, and it is associated with poor neurodevelopment. Nutrition plays an important role in postnatal growth, but growth is also influenced by other factors like co-morbidity, and, also, there might be sex differences. Methods: This is a cohort study including preterm infants < 32 weeks at birth (n = 21,825) from the Spanish Neonatal Network database. The effect of sex and morbidity (patent ductus arteriosus, bronchopulmonary dysplasia, necrotizing enterocolitis and late-onset sepsis) on weight gain as well as linear and head growth from birth to discharge/death was assessed with linear regression models adjusted by gestational age and Z-scores at birth. Results: The 4 selected morbidities had an independent effect on all 6 growth parameters studied, which was greater in the case of necrotizing enterocolitis: changes in weight, length and head Z-scores were –0.60 (95% CI: –0.66 to –0.55), –0.62 (95% CI: –0.70 to –0.54) and –0.63 (95% CI: –0.71 to –0.56), respectively. Weight gain and linear growth were overall more affected than head growth. Girls lost slightly more weight Z-scores (–0.03; 95% CI: –0.06 to –0.002) than boys after adjustment by morbidity. There were no significant gender differences regarding linear and head growth velocity (cm/week), although girls lost more head Z-scores (–0.14; 95% CI: –0.18 to –0.10). Conclusions: Main co-morbidities associated with prematurity have an impact on postnatal growth. Head growth is less affected than length and weight. Girls are at slightly higher risk of postnatal weight and head restriction after adjustment by morbidity.

Background: Public health measures (PHM) designed to contain the spread of COVID‐19 pandemic have influenced the epidemiological characteristics of other viral infections. Its impact on acute RSV bronchiolitis in infants of ≤24 months old has not been systematically studied in our setting.Objectives: To describe the monthly pattern of visits to the Paediatric Emergency Department (PED) of patients 0 to 14 years of age, the rate of patients diagnosed with RSV acute bronchiolitis per thousand inhabitants of 0 to 24 months, and the rate of them requiring hospital admission during the winter 2020–2021, in the context of local and national COVID‐19 restrictions and compare them to the four previous seasons.Methods: Interrupted time series analysis of patients assisted in the PED and diagnosed with or admitted for RSV acute bronchiolitis in a tertiary University Hospital from January 2016 to February 2020 (pre‐intervention period) and from March 2020 to June 2021 (post‐intervention period). Intervention: Preventive PHM implemented by the Spanish government weighted by the Containment and Health Index of the Oxford COVID‐19 Government Response Tracker.Results: The intervention was followed by an immediate reduction of the rate of visits to the PED of –19.5 (95% confidence interval [CI] –24.0, –14.9) per thousand, and the rate of diagnoses and admissions for RSV acute bronchiolitis of –44.3 (95% CI –73.8, –14.8) and –1.4 (95% CI –2.7, –0.1) per thousand, respectively, with a delayed rebound.Conclusions: After the implementation of PHM to prevent the spread of SARS‐CoV‐2 infection, an immediate and important decline in the visits to the PED was observed, with an upward change thereafter. There was also an initial reduction in the diagnoses of and admissions by RSV acute bronchiolitis. An upward trend was observed six to nine months after the usual time of the winter RSV epidemic, coinciding with the relaxation of the preventive PHM.