Baby Peter died after months of abuse despite visits from authorities
The attorney general is to consider whether the sentences handed down in the Baby P case were "unduly lenient".
Baroness Scotland will examine the case papers to see if they should be referred to the Court of Appeal.
Last week Baby Peter's mother, her boyfriend and their lodger were jailed for causing or allowing Peter's death.
Peter's mother must serve at least five years and the lodger at least three years. The boyfriend was given life for rape, with a 10-year minimum term.
He had been convicted of raping a two-year-old girl.
He was given an additional 12-year jail term, to run concurrently, for his "major role" in Peter's death.
Rape of a child under 13 carries a maximum sentence of life in prison
Causing or allowing the death of a child carries a maximum sentence of 14 years in jail, or a fine, or both
However, in cases where offenders are considered to pose a risk to the public, the judge can impose an indeterminate sentence
In passing this sentence, the judge will recommend a minimum term to be served before the offender can be considered for release.
Only after this time can the Parole Board consider whether the offender no longer poses a threat to the public and so is suitable for release
Lodger Jason Owen, 37, of Bromley, south-east London, was jailed for allowing or causing the boy's death.
Peter suffered more than 50 injuries including a broken back and broken ribs at a property in north London.
The injuries were inflicted despite Peter being on an at-risk register and receiving 60 visits from social workers, doctors and police over eight months. He died in August 2007.
Old Bailey Judge Stephen Kramer said in sentencing that his mother and Owens would be jailed indefinitely until "deemed no longer to be a risk to the public and in particular to small children".
He added: "Any decent person who heard the catalogue of medical conditions and non-accidental injuries suffered by Peter cannot fail to have been appalled."
Protect the public
A spokesman for the attorney general's office said: "We have called for the papers in this case since the attorney general has the power to refer certain sentences to the Court of Appeal for review if, after looking at all the facts, she thinks the sentence was unduly lenient.
"Within this power, the attorney general can look at minimum tariffs imposed on life and indeterminate sentence prisoners.
"However, it is important to understand that such prisoners are not released automatically after the minimum term has been served - they are only released when the independent Parole Board is satisfied that their continued detention is no longer necessary to protect the public."
Speaking after the sentencing, NSPCC chief executive Andrew Flanagan said: "We are disappointed that the minimum tariff was so low.
"It raises the question of how bad the abuse has to be before offenders get a longer minimum time in prison."
The attorney general has 28 days from the sentence date to refer the case to the court.