The figures, from the Organisation for Economic Co-operation and Development, show that the UK and Germany are tied at the top of a league table of average maternal age.
They also reveal that British women tend to wait an extra five years to have their first child compared with those in the United States, where the average age is 25.
The typical Frenchwoman has her first child at 28 and a half, while in Scandinavian countries the average age is around 28.
The OECD represents only industrialised nations, but because late motherhood is a first world phenomenon it is likely that Britain and Germany are home to the oldest mothers on the planet...
...Just behind the UK and Germany are countries such as Spain and Italy. In eight countries around the world, the average age at first birth is now above 29.
Women from poorer nations in Eastern Europe and Latin America tend to have their first child much earlier. The average age in Mexico is a little over 21, while in Latvia it is around 24 and a half.
The Top Ten according to the OECD Family Database (PDF) - mean age of women at the birth of the first child:
1. Germany / UK - 30 years
2. Italy - 29.9
3. Spain - 29.7
4. Switzerland - 29.6
5. Luxembourg - 29.3
6. South Korea / Japan - 29.1
7. Netherlands -28.9
8. Greece - 28.8
9. France - 28.5
10. Denmark / Ireland / Sweden - 28.3