Epidemiology and region-specific risk factors for low Apgar scores in China: a nationwide study.

BACKGROUND: Neonatal asphyxia is a serious public health issue. This study aimed to determine the epidemiology and region-specific risk factors for low Apgar scores, an important proxy for neonatal asphyxia, in China from 2015 to 2016. METHODS: The China Labor and Delivery Survey was a multicenter cross-sectional study including 96 hospitals distributed in 24 (out of 34) provinces. Logistic regression analysis was performed to examine the risk factors for a low Apgar score (< 7). Correspondence analyses were performed among neonates with low Apgar scores to explore the relationship between risk factors and geographical regions. The population attributable risk percentage (PAR%) was calculated for each region-specific risk factor. RESULTS: A total of 72,073 live births, including 320 births with low Apgar scores, were used for the analysis, giving a weighted rate of 3.9/1000 live births. There was a substantial difference in the incidence of low Apgar scores by geographic region, from 2.3/1000 live births in East China to 10.9/1000 live births in Northeast China. Maternal and obstetric factors are the major region-specific risk factors. In Southwest China, hypertensive disorders in pregnancy were more important contributors, with PAR% being 74.47%; in North and Northwest China, pre-pregnancy underweight was a more significant factor, with PAR% of 62.92%; in East China, infants born between 0:00 a.m. and 7:59 a.m. were a key factor, with PAR% of 80.44%. CONCLUSION: Strategies based on region-specific risk factors should be considered to reduce the burden of low Apgar scores in China.