Parents who lose a new baby run a high risk themselves of dying prematurely, according to a British study published on Thursday.

Investigators delved into a random sample of national death registrations for the years 1971 to 2006.

They compared deaths among parents who had been bereaved in the first year of a child's life or whose child had been stillborn, against deaths among parents whose baby had survived beyond the first year.

Bereaved parents were between two and four times likelier to die or become widowed in the first 10 years of the child's death compared with non-bereaved counterparts.

Mothers in particular were at threat.

Bereaved mothers in England and Wales were four times likelier to die prematurely, and bereaved mothers in Scotland six times likelier, than women whose child had survived beyond the first year of life.

The risk for mothers lessened slightly over time, but was still significant -- 50 percent higher -- after 25 years. After 35 years, it was 20 percent higher.

The reasons for the are unclear because the data do not give the details.

The authors speculate there could be a link with among bereaved parents, and suicide, too, may be a factor.

Alternatively, stillbirth and could be more common among who themselves are in .

The research, headed by Mairi Harper of the University of York in northern England, appears in the specialist journal BMJ Supportive and Palliative Care.