Related thematic articles: Beijing newborn birth defect rate doubled in 10 years & nbsp; Low premarital examination rate is the main cause. A reporter learned from Dongcheng District yesterday that according to the monitoring of 23 kinds of birth defects by the Beijing Health Bureau, the birth defect rate of newborns in Beijing has increased by nearly one time in the past ten years. A person in charge of the Dongcheng Family Planning Commission introduced that the top five birth defects respectively are congenital heart disease, limb malformation, urogenital malformation, lip cleft, and neural tube malformation. The birth defect rate of newborns in this city was 90.78/10,000 in 1997 and 170.82/10,000 in 2008, which increased by nearly one time in ten years. The main reason for the increase in the birth defect rate is the decrease in voluntary premarital examination rates among young men and women after the cancellation of mandatory premarriage examinations. The citywide premarital examination rate is less than 30%, and the number of advanced maternal age parturient women also increases year by year.