Abstract: ObjectiveTo explore clues to teratogenic factors of birth defects using flexible spatial scan statistic, so as to provide a new method for identifying teratogenic factors and reference for strengthening the comprehensive prevention and control measures of birth defects.MethodsData of birth defects in 2014 were derived from the Birth Defects Surveillance System in Guangdong Province (BDSSGP). Data of population density, industrial enterprises, waste gas emissions and waste water emissions were extracted from Guangdong Statistical Yearbook 2015. Spatial correlation and hot spot detection method of flexible spatial scan were used to observe the spatial clustering characters of birth defects and determine the relationship between society-economic indexes and birth defects.ResultsA total of 7 638 cases of birth defects were observed among 244 363 cases of perinatal infants reported in BDSSGP in 2014, with an incidence rate of 31.26 per thousand. The incidence of birth defects in males was 34.11‰, higher than that in females (27.69‰), and in urban area was 32.92‰, higher than that in rural area (29.82‰). The incidence rates of birth defects in puerperants aged less than 20 years and 35 years or above were higher than those in other age groups. The incidence rates of birth defects varied greatly in prefecture-level cities (P < 0.01). Flexible spatial scan analysis showed that the spatial distribution of birth defects in the whole province was clustered (P<0.05). Seven cities of Shenzhen, Dongguan, Zhuhai, Zhongshan, Foshan, Guangzhou, and Jieyang were highly clustered, with the RR values ranging from 1.14 to 2.53, while the rest of the 14 cities were not clustered. The population density, number of industrial enterprises, total amount of emission for industrial waste gases, total amount of industrial waste water discharge in clustered area were higher than those in non-clustered one (all P < 0.05).ConclusionThe incidence of birth defects was high in some area with obvious spatial distribution in Guangdong Province. The correlation between birth defects and socio-economic factors should be further researched in clustered area.