A recent paper in the British Medical Journal provided the first hard data on China’s male-female gap.  The study found that China now has 32 million more boys under the age of 20 than girls, and in 2005 there were 120 male births for every 100 females.  The gap has grown significantly in the last 20 years with the availability of ultrasound tests and abortion, and the gap is the widest among young children, meaning that the greatest distortion is yet to come.  The authors suggest a ban against sex-selective abortion, but even so,  China faces an excess of men for at least a generation, a situation that the Chinese government fears will affect social stability and security.

http://www.nytimes.com/2009/04/11/world/asia/11china.html?ref=asia