Objective To analyze the trend and related factors of perinatal birth defects in Huangshan City from 2019 to 2021. Methods According to the monitoring data of perinatal birth defects reported by 17 hospitals in Huangshan City from 2019 to 2021,the level of perinatal birth defects was analyzed. Results From 2019 to 2021,a total of 31 534 perinatal infants were monitored,683 cases of birth defects were reported,and 674 cases were verified and confirmed.The incidence of birth defects in the whole pregnancy week was 21 373/10 000 (674/31 534),and the incidence of birth defects in perinatal infants was 14 365/10 000 (453/31 534),with an increasing trend year by year (χ²_trend =5.137,P=0.023).The incidence of perinatal birth defects in urban areas was higher than that in rural areas (χ²=24.096,P<0.001).The incidence of birth defects at different maternal ages was different (χ²=7.698,P=0.006).Among the birth defects in the whole gestational week,the chromosomal abnormalities of the children over 35 years old in the elderly group were 3.286 (95％CI:1.802-6.024) times higher than those in the age group.The first five birth defects in the whole pregnancy are congenital heart disease,other malformations of the outer ear,multiple digits,chromosome abnormality and total cleft lip.Congenital heart disease ranked first in the birth defect sequence of the whole pregnancy week,and chromosome abnormality ranked first in the birth defect sequence of <28 weeks. Conclusion The incidence of perinatal birth defects in Huangshan is increasing.We should improve the rate of prenatal screening and prenatal diagnosis,enhance the diagnostic level of fetal cardiac ultrasound,strengthen comprehensive prevention and control of birth defects,and reduce the incidence of birth defects.