New South Wales police said the 21-month-old baby was admitted to Sydney's Wollongong Hospital after suffering seizures on January 25, Xinhua news agency reported.
The baby was tested positive for having consumed methylamphetamine, also known as "ice".
"Police were told the boy had slept alone in his mother's room the previous evening before he consumd the drug, where it was possible he had access to prohibited drugs," an NSW police statement said on Wednesday.
"Officers located and seized methylamphetamine, cannabis, cathinone, buprenorphine and drug paraphernalia."
The 27-year-old woman, from the suburb of Koonawarra, was charged with abandoning or exposing a child under the age of seven, causing danger of death and six counts of possessing a prohibited drug.
