But the advice given to expectant women in the early 1900s is a fascinating insight into their susceptability to fashion and fad.

The historical research by Tommy's Campaign, the charity that funds medical research into the problems of premature birth and miscarriage, coincides with National Pregnancy Week.

Among the more interesting pieces of advice given to mothers-to-be early this century was to avoid "exciting books, breathtaking pictures or family quarrels", and not to ride motorcycles or small cars over bumpy roads.

Sound body, unsound mind

Antenatal classes, almost a must for modern pregnancies, were unheard of in the early 1900s.

Diet advice during pregnancy has changed hugely

Women were considered "temperamentally unsound" if they took exercise or even rode a bicycle.

Fathers were certainly not encouraged to take an active role in preparations for the birth, as they are today.

These days, women are warned to avoid unpasteurised cheeses, liver, and alcohol, and to supplement a balanced diet with folic acid.

But in 1900, a pregnant woman might be told to avoid sour or salty foods, such as under-ripe fruit or pickles, as this was likely to result in a child with a "sour disposition".

Two pints of milk a day was considered the minimum requirement for good health.

The dangers of birth were far higher in the early part of the century.

More than 3,000 mothers died in childbirth each year, five mothers for every 1,000 births.

Caesarians often killed

Almost no pain relief was widely available until the 1930s, when 'gas and air' was taken out to homes by midwives.

The average length of labour was five hours less than it was today. Caesarian sections were very rare, and frequently proved fatal.

Most births took place at home, and because of the high rate of infections following birth, women were actually more likely to die if they went to hospital.

In the UK last year there were only 55 recorded deaths in childbirth, and 97% are delivered in hospital, with 16% by Caesarian section.

Attitudes to smoking in pregnancy have come full circle. In 1900, few women smoked, while it was actually thought of as healthy in the 1940s.

Now, women are aware that it can harm the unborn child.

The research has been commissioned by Boots the Chemist, which will publish it in full on its website on September 22.

National Pregnancy Week, launched on Saturday, is aimed at promoting healthy lifestyles to mothers-to-be.