BEIJING, Dec. 29 -- Chinese authorities handled 6,833 cases of illegal fetus gender tests and abortions in roughly one year, the National Health and Family Planning Commission (NHFPC) announced on Monday.

The NHFPC, Ministry of Public Security, together with other government departments, launched a nation-wide crackdown on illegal medical practices since October, 2013, during which 41,000 violations by medical and family planning institutions were discovered.

It is illegal in China for medical institutions or individuals to determine sex of a fetus unless it is medically necessary, or to perform sex-selective abortions.

Under China's one-child policy which has been eased in recent years and with a traditional preferences for male heirs, many Chinese women have chosen to abort after learning they were carrying baby girls, giving rise to a black market for such practices.

China adopted the family planning policy in the late 1970s to curb population, but had the side effect a sex ratio increasingly skewed toward men since the 1980s, when ultrasound technology used for identifying the gender of fetuses became available.

The NHFPC also briefed that 44,000 cases of unlicensed medical practices had been dealt with during the crack-down, with 1,373 transgressors in detention.

The NHFPC said, a lack of medical resources in some regions, city outskirts in particular, has squeezed migrant population into unlicensed health institutions.