Go Figure: When was the real baby boom?

Suddenly, babies are back, with a sharp rise in the birth rate. Michael Blastland tells the extraordinary statistical story of the original 20th Century baby boomers.

You were born into the most dramatic population change in UK history. At every age throughout your life, you stood out for sheer numbers.

But you were not born in the 1960s, or the years immediately after World War II, the groups usually thought of as the "baby boom" generations.

You were born in one year - 1920 - a year when the UK population stood at about 40 million, but still Britain's biggest year ever for babies.

But there's more to your story. It followed hard on the heels of one of the biggest collapses in births in UK history.

In fact, the generation of which you were part was born into three or four huge demographic upheavals within the space of seven or eight years. The first was World War I from 1914-18. Some of your age group are WWI babies.

The second demographic upheaval was caused by the Spanish flu of 1918-19 - more devastating, more lethal than the war.

These two events contributed for the three years at the end of the 1910s to about a quarter of a million fewer babies being born each year than might have been expected at the beginning.

And being born was only part of it. After that came survival. With rates of infant mortality about 15 times higher than those today, many of your generation did well to make it.

Then came the third event - in one year, 1920, a rebound in births so sudden, so big, that it remains the record year for babies in UK history, a record that survives despite a large increase in the UK population of childbearing age.

Imagine that every single class of 30 UK children in one year was followed a year later by a class of 37 or 38 - and you have something of the magnitude of that change. It's easily picked out in the charts.

Today, there's talk of a new baby boom. In 2010, there were about 807,000 live births in the UK, a rise of nearly 20% in a decade.

But 1920 beats that with ease, with probably well over 1.1 million live babies born in the UK as a whole, well above the post-WWII boom year of 1947, comfortably above the peak of the baby boom of the 1960s and far above the latest figures.

Only in Northern Ireland has the 1920 total ever been exceeded - as you can see in the second slide.

But the original 20th Century baby boom was also spectacularly short-lived.

This was the fourth event - the start of a renewed collapse of the birth rate, perhaps its longest and fastest ever, only a year later, quite unlike the more sustained boom of the 1960s and completing a sequence of down, up and then down again in the space of a few years by magnitudes that make you wonder how midwives, hospitals, schools and others coped on this rollercoaster.

There were massive upheavals in the years around 1920

You can watch the age group from 1914 to 1920 move through the generations in this interactive ONS graphic (England and Wales only).

It shows what's known as a population pyramid at each census from 1901 to 2001. The babies of the Great War, the flu and the original baby boom can be seen from 1921 onwards, working their way through the years and the ages, as a cut in the side of the pyramid followed by an abrupt spike.

And what of these babies now? Today, those remaining are all in their 90s.

The total UK population born from 1914 to 1920 altogether, male and female, once numbering about 6.5 million, is still over 300,000 strong. But within that, some groups are dwindling fast.

Of men born in 1914, for example, there are probably only about 4,000 still alive.

They will be with us for a while yet. But the generation born into the Great War, the Spanish Flu and the UK's fastest and biggest ever baby boom, all in the space of a few turbulent years, is beginning to go its way.