746 - Major congenital anomalies: 23 years of incidence and postnatal outcomes in the NEOCOSUR neonatal network.

Publication Number: 746.5979

Ivonne L. D'Apremont, Pontificia Universidad Católica de Chile, SANTIAGO, Region Metropolitana, Chile; Alberto Toso, Pontificia Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile; Claudia A. Musalem, Red Neonatal NEOCOSUR, Santiago, Region Metropolitana, Chile; Paulina A. Toso, Pontificia Universidad Catolica de Chile, Santiago, Region Metropolitana, Chile; Maria Eugenia. Hubner, Clinica Alemana, Santiago, Region Metropolitana, Chile

Background: Major Congenital Anomalies (MCA) are a relevant cause of infant mortality, generally underestimated. WHO reports 8,000,000 cases per year but local registers are scarce. Also, there is a lack of data and reports in our region.

Objective: To describe the incidence, general characteristics, and mortality of very-low-birth-weight (VLBW) infants with MCA in the NEOCOSUR neonatal network between 2001 and 2023.

Design/Methods: Retrospective cohort study, employing prospectively collected data, including infants between 23 to 36 weeks' gestation, weighing 400-1500 g and born at 40 South American Neonatal Intensive Care Units (NICU) from the NEOCOSUR Neonatal Network between 2001 and 2023.
The incidence of MCA was analyzed according to gestational age and birth weight. The incidence of MCA by system involved was also described. The overall mortality of patients with MCA and the site of occurrence (delivery room/post-admission) were described. Postnatal age at death was determined by Kaplan-Meier analysis.

Results: A total of 32,863 VLBW infants were born in the NEOCOSUR network centers during the study period, of which 1810 patients presented MCA (5.5%). The incidence according to gestational age and birth weight is shown in Table 1. An increase in the proportion of infants < 1500 g with MCA was observed with higher gestational ages. No differences were observed by birth weight range. Table 2 describes the types of MCA (data since 2012, 66% had a specific ACM recorded). Cardiac defects (20%), central nervous system defects (18%), and chromosomal anomalies (17%) are more frequent. Overall mortality was 61.4% (n=1111); 35% died in the delivery room, and 65% died post-admission. Figure 1 shows Kaplan-Meier analysis of age at death of all patients with MCA. The median time of death in infants with MCA was 9 days. In contrast, the median number of days to discharge of surviving children with MCA was 66 days.

Conclusion(s): The overall incidence of MCA in the NEOCOSUR neonatal network is 5.5%. There is an increase in the proportion of VLBW infants with MCA at higher gestational ages and cardiac defects stand out as the main MCA. Mortality in this population is 61.4%, with 35% of deaths in the delivery room. Survivors have a prolonged length of stay with a median hospital stay of 66 days. It is necessary to continue working locally and in networks to improve the data of ACM and the characterization of this relevant population.

Table 1. Incidence of major congenital anomalies (MCA) by gestational age and birth weight in VLBW infants of the NEOCOSUR neonatal network between 2001 and 2023.


Table 2. Major congenital anomalies and incidence by type of anomaly. Data available since 2012. Patients with at least one anomaly= 773; Total anomalies recorded= 1167.


Figure 1. Age of death among infants with major congenital anomalies (MCA). Kaplan-Meier analysis of non-survivors infants (n=1111). The median time to death of infants with MCA was 9 days.