The Argentinean women both gave birth on September 30 at the Sanatorio Argentino, a private clinic in San Juan.
Maria Lorena Gerbeno, 37, a lawyer from San Juan, admitted she became suspicious soon after giving the birth.
The mother-of-three gave birth by C-section and was told her daughter weighed 6lbs 8 ounces, before she was taken away.
However when she was returned, the child suddenly weighed 8lbs 4 ounces and staff claimed that she was delivered through a breech birth.
'I spent three weeks with a baby that was not my daughter'
‘I told them that could not be but they said I must have misunderstood. I never got any answers,’ she recalled.
And Maria’s maternal instinct continued to tell her something was not right.
Then, 3 weeks later, Gerbano struck up conversation with another mother, Veronica Tejada, at a clinic check-up.
Veronica had given birth to a baby girl on the same day, and her daughter had weighed 8lbs 4 ounces, before being returned weighing 6lbs 8 ounces.
Realising the massive error, Gerbeno made a criminal complaint and had a judge order DNA testing, which confirmed last week that the babies had been accidentally switched at birth.
The mothers spent last week exchanging tips and photos, before making the official swap at the beginning of this week.
‘I spent three weeks with a baby that was not my daughter but I gave her all my love and knew that the other mom would do the same,’ Lorena Gerbeno told the local station C5N.
The mothers met in court to exchange the babies on Monday, and are considering legal action against private San Juan clinic.