Maternal and neonatal exposure to risk factors for neonates with moderate or severe hypoxic ischemic encephalopathy: a cross-sectional study

Background To investigate the association between maternal and neonatal exposure to the relevant influencing factors and risk of moderate or severe hypoxic ischemic encephalopathy (HIE), and the possible interactions in the Chinese population. Methods A cross-sectional study comprising 228 neonates from Henan Children's Hospital during the five-year period 2015-2020 in China was conducted. All neonatal basic demographic information and clinical records were documented from the neonatal HIE database. Comparisons between mild HIE and moderate or severe HIE were conducted with the t-test or Wilcoxon rank-sum test for continuous variables and the Chi-square test for categorical variables. Unconditional multiple logistic regression models were used to generate the odds ratios(ORs) and 95% confidence intervals(CIs). In addition, we also used an additive model to test for possible biological interactions among the factors. Results Of the 228 neonates, the males had a statistically significantly higher frequency compared with the females between the two groups (P = 0.030). Trend analysis results found that with the decreased of the neonatal birth weight, the detection rates of moderate or severe HIE in males and females were gradually increased (P-trend < 0.05). The detection of moderate or severe HIE in males and females increased with the decreased of neonatal gestational age at birth(P-trend < 0.05). However, no interaction was detected between neonatal birth weight and gestational age at birth based on the additive model, the Relative Excess Risk of Interaction and 95% CI was 0.821(-0.046,1.687). The adjusted multiple logistic regression model showed that low birth weight(ORadj:1.965, 95%CI:1.086-4.127),premature infant(ORadj:1.557, 95%CI:1.589-4.862),1-min Apgar's score < 7(ORadj:5.618, 95%CI:3.724-7.353),intrauterine distress(ORadj:4.916, 95%CI:3.431-7.398),amniotic fluid contamination (ORadj:3.965, 95%CI:2.153-5.782) significantly increased the risk of neonatal moderate or severe HIE. Conclusion Neonates with low birth weight, premature infant,1-min Apgar's score < 7, intrauterine distress, amniotic fluid contamination are risk factors for moderate or severe HIE. Notably, we found no biological interaction between risk factors based on the additive model, these findings may help to inform prevention strategies, as this may effectively reduce the incidence of neonatal moderate or severe HIE.