[Prevalence of birth defects in the Tongzhou District of Beijing between 2006 and 2012]

To study the dynamic prevalence and epidemiological characteristics of birth defects distribution in the Tongzhou District of Beijing between 2006 and 2012.

Data collected from the birth defects surveillance system in the Tongzhou District of Beijing between 2006 and 2012 were used. The prevalence and trends of birth defects were analyzed, also the proportion of birth defects in prenatal diagnosis was calculated.

Between 2006 and 2012, 1,165 cases of birth defects were identified among 92,340 births, with a prevalence of 12.62‰. The prevalence of birth defects showed an increased trend during the seven years (χ2=6.77, P<0.01). The prevalence in the flowing population (13.27‰) was higher than that in the permanent residents (11.55‰), and the former showed an upward trend during the seven years (χ2=25.02, P<0.01). The top five birth defects were congenital heart defects, polydactyly, cleft lip and/or palate, neural tube defects, and external ear malformation in turn. The prevalence of congenital heart defects and the unspecified congenital malformation increased while that of neural tube defects decreased. There was also an upward trend of the prenatal diagnosis for congenital heart defects (χ2=14.80, P<0.01).

The prevalence of birth defects increased in the Tongzhou District of Beijing from 2006 to 2012, and it was mainly caused by the increased prevalence of birth defects in the flowing population, the increased number of unspecified birth defects and the improvement of diagnosis technology for congenital heart defects.