At least one million babies are born with defects in China each year, an incidence rate of 60 out of every 1,000.

"The rate is three times that of developed countries," director with the National Centre for Maternity and Infant Health, Professor Li Zhu said on the occasion of National Birth Defect Prevention Day on Wednesday.

The late childbearing trend has become one of the major factors behind congenital defects, Li was quoted as saying by China Daily.

Women over 35 who give birth face greater risk of their babies being born with mental and physical defects, Li added.

Defects include cleft palettes, neural tube defects, abnormal numbers of fingers or toes, congenital heart disease and water on the brain.

Health experts consider the best childbearing age is between 25 and 30 years old.

But many Chinese couples, especially urbanites, are choosing to have a child later in life because of heavy work pressures and fast-paced lifestyles.

Apart from late childbearing, birth defects occur for many other reasons, including insufficient consumption of certain trace elements primarily folic acid and iodine, exposure to health hazardous pollutants, and long term unhealthy lifestyles.

Among the babies born with defects, just 30 per cent of them can be cured or treated. Another 40 per cent suffer lifelong deformities, while the remaining die shortly after birth, health experts said.

Statistics from the Ministry of Health show that birth defects affect one in 10 Chinese households, imposing a total annual financial burden of one billion yuan (USD132 million).

Nearly 30 million Chinese households are raising or have raised babies born with defects.

Couples are advised to undergo health examinations before and during pregnancy to lower the risk of birth defects.

Couples have the right to abort a pregnancy if defects are detected, Li said.

Since pre-marriage medical check-ups was made optional nationwide in October 2003, the number of people undergoing the check has dropped tremendously.