Hypoxic ischemic encephalopathy: Do peripartum risk factors account for observed changes in incidence?

Analyze the temporal trends in hypoxic ischemic encephalopathy (HIE) and peripartum risk factors from 2010-2019. This is a secondary analysis of a prospective cohort in the California Perinatal Quality Care Collaborative (CPQCC), which includes infants with qualifying conditions, and is linked to the California Department of Public Health Vital Statistics birth cohort. This analysis includes live births ≥ 36 weeks’, born 2010-2019, and excluded delivery room deaths or those with unknown HIE status. We performed a trend analysis with linear regression to analyze the rate of peripartum risk factors, mild, moderate and severe HIE (based on Vermont Oxford Criteria). We compared peripartum characteristics between those with and without HIE. Unadjusted and multivariable hierarchical logistic regression were performed to determine factors associated with any or moderate or severe HIE. 62,888 infants met inclusion criteria and 4,193 were diagnosed with HIE. Over a 10-year period, the incidence of HIE more than doubled, with the greatest increase in moderate HIE (Figure 1). Chorioamnionitis, diabetes, obesity, hypertension (HTN), antepartum bleeding, fetal distress, operative vaginal delivery and prolonged rupture of membranes ( >18 hours), significantly increased. The prevalence of cesarean delivery (CD) is higher among neonates with HIE than without HIE. Overall, the rate of CD is decreasing, but it has decreased more in those diagnosed with HIE than those without HIE. In the multivariable analysis, birth year, small for gestational age, patients with chorioamnionitis, HTN, antepartum bleeding, CD and higher education were associated with increased odds of any HIE or moderate or severe HIE (p-values < 0.05, Table 1). Neonatal HIE and peripartum risk factors have steadily increased in this population. Maternal bleeding, CD, chorioamnionitis and HTN are most strongly associated with HIE. The rate of CD has decreased more in those with HIE versus those without HIE. These associations should be investigated further, accounting for labor characteristics and ascertainment bias.View Large Image Figure ViewerDownload Hi-res image Download (PPT)