A newborn baby was found abandoned in a drain in Sydney on Sunday. The boy, who is only a few days old, is in a serious but stable condition in Sydney's Westmead Children's Hospital. Provided By Associated Press

A 30-year-old Sydney mother has been charged with the attempted murder of her newborn son whom she allegedly abandoned in a roadside drain, police said on Monday.

The week-old baby is in serious but stable condition in Sydney's Westmead Children's Hospital, after spending five days in a 2.5-meter deep drain beside the M7 motorway in the suburb of Quakers Hill. A group of cyclists found him.

His mother, Saifale Nai, of Quakers Hill, did not appear in Blacktown Local Court on Monday to answer the charge. She faces a potential maximum sentence of 25 years in prison if convicted.

Her lawyer did not apply for bail or enter a plea to the charge. The magistrate refused bail.

Nai will remain in custody until she appears at Penrith Local Court on Friday.

"The baby, believed to have been born on Nov 17, was placed in the drain the following day," police said.

Andrew Pesce, a gynecologist, obstetrician and former president of the Australian Medical Association, said such an ordeal could leave a newborn baby with long-term problems such as brain damage.

"There would still have to be some concerns about the baby," Pesce said.

"I would have thought that it wouldn't have been able to survive for much longer if it didn't start getting fed," he added.

He said healthy newborns have reserves to cope with relative malnutrition and often lose 10 percent of their birth weight because their mothers can take a few days before producing sufficient milk.

Helen Polley, a senator in the opposition Labor Party, said the near-tragedy could have been avoided if emergency hatches were set up at Australian hospitals, police stations and fire stations so babies could be abandoned safely.

Polley also called on Sunday for the repeal of laws that make child abandonment a criminal offense, which she said encourages the problem to be hidden.

Wrapped in blanket

The baby was found wrapped in a hospital blanket. Police used hospital records to find the mother.

Quakers Hill Police Inspector David Lagats said on Sunday the boy had no signs of physical injury, but was malnourished and dehydrated.

Cyclists riding in a lane beside the motorway heard the baby on Sunday morning.

"We actually thought it was a kitten at first, but when we went down there we could hear exactly what it was - you could definitely tell it was a baby screaming," cyclist David Otte told The Daily Telegraph newspaper.

It took six men, including three police officers, to lift a 200-kg concrete lid that covered the drain, the newspaper said.

Police suspect the baby was squeezed through the drain's narrow opening and dropped to the bottom.

The boy will probably be taken into state care when he is discharged from the hospital, officials said.