The number of cot deaths in England and Wales has fallen to the lowest number since records began, figures show.
In 2004 when records began, there were 207 sudden infant deaths, also known as cot death.
But in 2014, the latest figures available, the number had dipped to 128, according to provisional data from the Office for National Statistics (ONS).
Commenting on the figures, Francine Bates, chief executive of charity The Lullaby Trust, said: "Whilst it is extremely good news that Sids (sudden infant death syndrome) has gone down in England and Wales, evidence has shown that many more babies' lives could be saved if all families had access to and followed safer sleep advice.
"It is very important that we work together to ensure safer sleep messages consistently reach all families, particularly those at increased risk such as young parents and families living in areas with higher Sids rates."
The ONS report on unexplained infant deaths - deaths among children under one year of age - includes both sudden infant deaths and deaths for which the cause remained unascertained after being investigated.
Overall there were 212 unexplained infant deaths in England and Wales in 2014.
Three in five of the deaths were recorded as cot deaths, with the remaining 40% were recorded as unascertained.
Just over half (55%) of all unexplained infant deaths were boys in 2014.
Rosie Amery, from the ONS's health analysis and life Eevents team, said: "Unexplained infant deaths in 2014 were the lowest on record, driven by a decrease in sudden infant deaths.
"A number of factors may have contributed to the fall, including warmer-than-average temperatures throughout the year, fewer women smoking at the time of delivery, and greater awareness of safer sleeping practices."