While overall child mortality fell by 50 percent in the past 20 years, young maternal age was found to be a risk factor for death in early childhood, according to a report on child deaths in the UK.
Support should be extended to mothers of all ages, not just first-time teenage mums, the report said.
The research was led by the Institute of Child Health at UCL, the BBC reported.
It looked at why children die in the UK using death registration data from January 1980 to December 2010.
It focused on child injuries, birthweight and maternal age to assess the risk factors for child deaths.
The research found that in England, Scotland and Wales, the difference in mortality between children of mothers under 30 and those born to mothers aged 30 to 34 accounted for 11percent of all deaths up to nine years old.
This is equivalent to an average of 397 deaths in the UK each year, the report said.