Donna Anthony's is the latest in a series of well-publicised cases regarding infant deaths.
Donna Anthony was jailed for murder in 1998
In January 2003, solicitor Sally Clark, who had been jailed for murdering her two baby sons, was cleared by the Court of Appeal.
Three judges decided that her conviction was unsafe.
Angela Cannings spent 18 months in jail, but her conviction was quashed in December 2003 when key medical evidence against her was discredited
Ms Cannings had been jailed for life in April 2002 for the murder of seven-week-old Jason in 1991 and 18-week-old Matthew in 1999.
In 2003, 35-year-old pharmacist Trupti Patel was cleared of murdering her three babies, by a jury at Reading Crown Court.
She had denied this, saying the boys were victims of sudden infant death syndrome (SIDS) or cot death, due to a genetic defect.
Ms Patel was cleared in June 2003. Her legal appeal was based on several factors including that the evidence of Professor Sir Roy Meadow - also instrumental in the Sally Clarke and Angela Cannings cases - was misleading.
When Ms Cannings was convicted, the jury was told the deaths of her children could not have been caused by a genetic defect because there was no evidence of other infant deaths in her close relatives.
All three of the cot death cases highlight difficulties for police investigating sudden infant deaths.
Ms Anthony from Yeovil, was released by the High Court on Monday.
The 31-year-old's case was originally referred to the Criminal Case Review Commission (CCRC) in September 2003.
In 2004, the attorney general announced a review of 297 cases following a judgment in the Cannings case, with 28 referred to the CCRC following the quashing of Ms Cannings' conviction.
Donna Anthony's lawyer, George Hawkes, told the BBC her life had been "devastated by events".