However, some misunderstood the new regulations and mistakenly assumed that the checkup no longer existed. Statistics from the Ministry of Health show that the number of people who took the checkup nosedived to 3 percent in 2004 from 80 percent the previous year.

Birth defects

The incidence of birth defects has increased across China in recent decades. The Ministry of Health said in September that three out of every 200 babies born in 2011 had a birth defect, double the rate in 1996.

Those calling for the reinstatement of mandatory premarital health checks blame the phasing out of the procedure for the rise in the number of birth defects.

Most happen in the first three months of pregnancy and can be caused by genetic factors or even a prepregnancy infection. Other factors are at play too. Some defects result from exposure to medicines or chemicals - for example, alcohol abuse can cause fetal alcohol syndrome, which affects growth patterns and can sometimes result in mental health issues.

Birth defects can affect physical appearance or bodily functions, or both. Some, such as a cleft palate, are structural and easily identifiable. Many can be prevented through premarital checkups, and later examinations performed before and during pregnancy.

Ji Lianmei, a doctor at Beijing United Family Healthcare, said that the checkups provide better knowledge of a couple's health and can identify potential birth defects. Every year, around 800,000 to 1 million babies are born with defects or illnesses, such as cardiac problems in China.

"The statistics only record defects in very early infancy. But some defects don't show up until the child is aged 5 or 6 years, so the real number is likely to be even higher than that indicated by the official statistics," said Ji.