BEIJING - The number of birth defects in China's capital has almost doubled in the last decade, the city's health bureau said.
There were 170 birth defects per every 10,000 births in Beijing last year, compared with 90 per 10,000 in 1997, it said.
Ren Aiguo, head of the reproductive health institute at Peking University, said the main reason for the increased numbers was better diagnostic techniques in the city, which meant more cases were recorded than before. Other factors include more older women having children and a change in diet from vegetables to more processed food.
In rural areas of China, where the percentage of birth defects is much higher than in Beijing, the problems have also been blamed on a lack of folic acid in the diet, which can cause neural tube defects that can damage the baby's spine and brain.
Other risk factors include obesity, alcohol, smoking and infections.
China has a high rate of birth defects, affecting 4 to 6 per cent of newborns nationwide. Around 800,000 to 1.2 million babies are born with birth deformities, the health bureau said on its Web site.
In the United States the figure is around 3 per cent of newborns.
Ren said in an interview that there was no evidence that pollution was behind the increased the number of birth defects in Beijing.
Every year more than 7.9 million children, or 6 per cent of total births worldwide are born with birth defects due to genetic or environmental causes, according to the World Health Organization. The most common are congenital heart defects, neural tube defects and Down's syndrome.
