Temporal and seasonal variations in incidence of stage II and III NEC-a 28-year epidemiologic study from tertiary NICUs in Connecticut, USA

Objective To investigate seasonality and temporal trends in the incidence of NEC. Study design A retrospective cohort study from two tertiary NICUs in northern and central Connecticut involving 16,761 infants admitted over a 28-year period. Various perinatal and neonatal risk factors were evaluated by univariate, multivariate, and spectral density analyses. Results Incidence of NEC was unchanged over the 28 years of study. Gestational age, birth weight, and birth-months (birth in April/May) were independently associated with stage II or III NEC even after adjusting for confounding factors (p < 0.05). Yearly NEC incidence showed a multi-modal distribution with spectral density spikes approximately every 10 years. Conclusion(s) Temporal and seasonal factors may play a role in NEC with a peak incidence in infants born in April/May and periodicity spikes approximately every 10 years. These trends suggest non-random and possibly environmental factors influencing NEC.

Automated summary

The study found that the incidence of NEC remained stable over a 28-year period, with gestational age, birth weight, and specific birth months being independently associated with NEC risk. Additionally, NEC incidence showed multi-modal distribution with periodic spikes approximately every 10 years, indicating potential non-random and environmental factors influencing NEC.