Some 39 of them were detained at the institute in Bangkok on drug-related charges awaiting trial.

"Two of them are heavily pregnant and are now separated from other prisoners," Angkhaneung said. The women were being held on court orders, she added.

Angkhaneung said correctional facilities had doctors to provide pre-natal care for the pregnant detainees. "Then, these detainees will be sent to a hospital outside the prisons to give birth to their babies," she said.

The Corrections Department would also contact their relatives to get them to take care of the babies.

"If no relatives show up, we will take care of these children until they reach the age of six years old. After that, we will transfer them to the care of the Public Welfare Department," she said.

Angkhaneung said some female detainees had got pregnant while in jail.

She spoke after the Cabinet approved a proposal on Tuesday for legal amendments that would delay punishment for pregnant convicts by a few years. The move aims to allow pregnant convicts to give birth and take care of their children while they're babies, before they are sent to jail.

The proposal was put forward by the National Human Rights Commission (NHRC).