South Korea announced a crackdown on abortionists as part of a drive to boost its low birthrate, a pressing issue in the rapidly ageing society.
The health ministry said it would establish a "call centre" on illegal abortion and informants would receive rewards.
Obstetricians involved in illegal abortion will be referred to prosecutors for criminal charges, it said.
An association of obstetrics and gynaecology also promised to expel members who do not follow government guidelines.
Official data showed the birth rate -- the average number of babies born during a woman's lifetime -- was 1.15 in 2009, the lowest since 1.08 in 2005, as more couples delayed marriage.
Some 445,000 babies were born last year, 4.4 percent down from 2008. The number of marriages decreased five percent year-on-year in 2009.
South Korea has offered a variety of incentives to encourage people to have children. Authorities warn the population, currently almost 50 million, could start declining within a decade.