The first time South Korean lawmaker Yong Hye-in left the house after giving birth, she ended up in tears when she was denied entry to a cafe because of her baby.

The experience gave Yong, who at 33 is one of the country's youngest National Assembly members, a new mission: eradicating South Korea's burgeoning "no-kid zones."

In a country with the world's lowest birth rate, the emergence of an increasing number of facilities barring children — such as cafes, libraries and art galleries — is infuriating parents like Yong and, she says, inadvertently thwarting decades of government policy.