An important aim of the premarital check is to gather basic knowledge about a patient before pregnancy, because the information it provides can be crucial. One of the advantages is that the check can provide clues about whether a woman should take preventive measures, such as using folic acid which can prevent defects such as spina bifida.

A paper written by experts from Peking University's Institute of Reproductive and Child Health shows that 80 percent of women took folic acid when the premarital checkup was compulsory, but the rate fell to 30 percent when the tests became voluntary. Moreover, the number of women taking folic acid in early pregnancy dropped by 20 percent once the checkups ceased to be mandatory.

The paper also indicated that the number of women exposed to risks, including x-rays and alcohol and illegal drugs, in early pregnancy doubled after the publication of the new marriage regulations in 2003.

The premarital checkup also includes a test for HIV and can identify potential problems with the reproductive organs, neither of which can be isolated by regular health checks. If problems are suspected, the doctor will give the prospective parents a checklist of things to watch for during pregnancy.

Free checkups

Standing outside the Xishan district center for women and children's health in Kunming, Yunnan province, 50-year-old Han Lingjie waited for her niece to finish the premarital checkup. Han is a firm believer in the efficacy of the premarital checkup and said it should be mandatory once again.

She said the younger generation is more open about sexual matters and the number of people reporting cases of contagious disease has increased during the past 10 years. For Han, this simply underscores her conviction that the checks must again become compulsory. "When I was young, syphilis and HIV/AIDS were almost unheard of," she said, recalling that 30 years ago lovers often did not even dare to kiss before marriage.

Han said she would not allow her 21-year-old daughter to marry a man with a contagious disease, even if effective treatment was available. "Some people may hide their health problems, so premarital checkups are essential," she said.

But for her niece, 22-year-old Tan Mingyi, the checkup is simply a way of learning more about her health rather than an "entrance exam" for marriage.

"We have known each other for years and even if the checkup suggests health problems, we will still get married," said Tan. She said most of her friends were alerted to the importance of the checkup by their parents and they were positive about it.

"All my friends had the checkup before their marriage registration. We are confident and know that marriage has pros and cons," said Deng Weigang, Tan's fiancee. "We were surprised to discover that the checkup is free. That's great."

Simplified procedures

The Xishan district center has provided free premarital checkups since September 2010. If payment were compulsory, the tests would cost around 300 yuan ($48) per couple. To simplify the procedure, the center has established branch offices in the same buildings as the civil affairs bureau where couples apply for marriage registration.

"The whole process only takes an hour and it's free. So the number of people having the checkups increased sharply last year. People simply said 'Why not?'" said Shan Wenhua, the director of the center.

In autumn 2009, the center tested the use of free checkups. At the time, the civil affairs bureau and checkup office were 5 km apart. Shan said the staff had difficulty persuading people to have the checkup, even though free transportation was provided between the offices.

"They thought it would take half a day. Some people got into the car and then got out again. The distance put them off," he said. "But the premarital checkup is voluntary, so we can only encourage people to take it, we can't force them."

When the new marriage regulations were introduced in 2003, the number of people that had the premarital checkup in Xishan plummeted to less than 2 percent annually. However, the introduction of free checks helped reverse the decline and in 2011, roughly eight in 10 registered couples had the examination. Between January and August this year, the number hit 100 percent.

However, despite the benefits provided by the checks, it seems that some old, romantic attitudes take precedence.

"Marriage is only about love. We are not pigs that need to be screened and tested before being turned into canned meat," said Xue Peng.

Tang Yue contributed to this story.

Contact the reporter at yangwanli@chinadaily.com.cn