The BBC's Toby Sealey: Death rates are higher for babies born outside marriage

Low birthweight is also a risk factor for children aged between one and three, although infant mortality in general is now at its lowest levels ever.

The figures are published by the Office for National Statistics (ONS) in its quarterly health bulletin and cover England and Wales.

It is the first time that such data has been recorded for three year olds.

Previous research on infants has shown similar differences, which are mainly attributed to deprivation.

The researchers also found a higher risk for children born to mothers from the New Commonwealth countries, mainly Bangladesh, India, Pakistan, East Africa and the Caribbean.

Cancer risk

The ONS bulletin, which contains a variety of different studies, includes a 26-year study on father's occupations and childhood mortality which shows "notable differences" in social class and childhood deaths.

It also shows a link between a father's job and cancer.

Fathers whose work exposes them to agrochemicals or who work in the agriculture indsutry may increase their child's risk of contracting kidney cancer, says the study.

This is based on research published about 18 months ago which shows there is a small increased risk of contracting a kidney cancer called Wilms' tumour if the child's father works in agriculture.

But the researchers warn that there may be many other factors involved.

The ONS says death rates are continuing to fall as is fertility and deaths from hypothermia are also down.

But the number of men aged 35 to 39 who are dying rose by 7.5% between 1997 and 1998.

Health experts blame increases in prostate and testicular cancer and a rise in suicide.

The number of men being treated for depression and anxiety was 19% higher in 1996 than in 1994 and 15% up for women.

There was also a 10% increase in the treatment of high blood pressure and diabetes over the same period.

Social gap

The bulletin once again shows a stark difference in health between rich and poor.

Treatment for coronary heart disease and depression was 40% higher in industrial areas than in professional areas.

Men in routine occupations had a mortality rate that was nearly three times higher than men in professional jobs.

British fertility is continuing to drop

Although life expectancy has increased for all social classes since 1972, but the ONS says "this disguises increasing inequality".

The difference between life expectancy and birth between professional men and manual workers has risen from 5.5 years in 1972-76 to 9.5 years in 1996.

The difference for women has increased from 5.3 years to 6.4 years.

The variations were decreasing for women until 1991, but have begun to widen in recent years.

Abortion

Another study shows that abortion figures are continuing to rise.

Ann Furedi say a rise in abortion is not necessary bad news

In 1998, there was a 4.2% increase on 1997 figures, with abortions among under 20s rising by 11%.

In the 20 to 29 age group, the number only rose by 1%, but in the over 30 age group the figure was 6%.

Ann Furedi, spokeswoman for the British Pregnancy Advisory Service, said: "The increase in the abortion rate may be because abortion is seen by more women as an acceptable way to manage an unwanted pregnancy.

"The abortion rate rose steeply after the pill scare in 1995. This was widely publicised and may have educated women that abortion is a legal and safe choice.