The rate of pre-marital health checkups in China has dropped from 95 percent to less than three percent since the testing became voluntary in 2003, said Vice Health Minister Jiang Zuojun at a meeting on women and infants health care in Hangzhou, capital of east China's Zhejiang province.

The decline in testing has made it more difficult to identify infectious diseases, challenging the quality of the Chinese population, Jiang said.

Pre-marital health checks used to be compulsory to obtain a marriage permit in China. But under the new regulations on Marriage Registration adopted in October 2003, the process was made voluntary. Given the majority of tests cost money, 97 percent choose not to have them.

Some local governments in Zhejiang, Shanghai, Beijing and Shandong have made pre-marital check-ups free of charge.

As a result, east China's Zhejiang province has seen its checkup rate rise from less than 1.6 percent in 2004 to 20 percent this year, said Ye Zhen, vice director of the provincial health department.

South China's Guangxi Zhuang Autonomous Region have launched publicity campaigns to spread information about pre-marital checkups and some underdeveloped areas have seen a checkup rate of 70 percent, according to the region's health department.