Objective: To explore the correlation between air pollution and birth defects during early pregnancy in Hefei area, and provide a basis for effective prevention and control of birth defects. Methods: The data on 48 131 perinatal births delivered from October 2015 to September 2017 in Hefei were collected by using the direct report system of China’s Maternal and Child Health Monitoring Data, including 1 530 cases of birth defects. We also collected data on ambient air pollution during the same period from 10 monitoring sites in Hefei to analyze the correlation between birth defects and the concentration of each pollutant by using Spearmen correlation analysis. Results: The incidence of birth defects during the study period was 31.79‰, and the top six perinatal birth defects were congenital heart disease (9.49‰), external ear deformity (2.87‰), polydactyly (toe) (2.16‰), cleft lip and palate (1.56‰), Down’s syndrome (1.04‰), and congenital hydrocephalus (0.91‰). The incidence of congenital heart disease was related to the exposure to nitrogen dioxide (NO2) during the first month of pregnancy, particulate matter less than 10 μm in aerodynamic diameter (PM10) and carbon monoxide (CO) during the fourth month of pregnancy. The incidence of external ear deformity was correlated with exposure to PM10 during the fourth month, CO during the sixth month of pregnancy. The incidence of cleft lip and palate was correlated with exposure to CO during the third month, and ozone (O3) during the sixth month of pregnancy. The incidence of congenital hydrocephalus was correlated with exposure to NO2 during the fifth month of pregnancy. Conclusion: Exposure to air pollutants during part of pregnancy is associated with the incidences of some birth defects.