However, there are also 23 places where fertility is “significantly lower” than might be expected for the region as a whole. Limburg province is especially infertile, with Lommel, Mol, Neerpelt, Tongeren and Hasselt, among others, making the list. Antwerp province has Schilde, Vosselaar, Brasschaat, Heist-op-den-Berg and Herentals. East Flanders provides Erpe-Mere, Haaltert and Zottegem, and West Flanders Bruges and Koksijde.

In Flemish Brabant, the only place affected by lower-thanusual fertility is the city of Leuven, apparently a result of the large population of students.

The study, which looked at all 308 Flemish municipalities between 2003 and 2007, is part of a three-pronged examination of the population of Flanders, examining fertility, migration and death – the beginning, middle and end of the population narrative, as it were. When completed, it will form the basis for a whole range of policy decisions.

The study also looked at the differences between Belgians and non-Belgians, and found non-Belgians are 89% more fertile than Belgians – or at least, they have 89% more births, once other factors such as age have been adjusted for.

In the cities, the difference is greater still. In Antwerp, non-Belgians outbirth the natives by 125% - for every 100 births to natives, there are 225 births to immigrants, regardless of origin. In Ghent, foreigners are 112% more fertile than Belgians, and in Mechelen the difference is 163%, the highest in Flanders.

The study’s authors attribute the difference to the character of each city’s foreign population. “Antwerp and Mechelen have high concentrations of foreigners of North African origin – populations with a traditionally higher fertility rate than other foreigners,” the study says. “Other cities like Ghent, Leuven and Genk have a relatively high number of foreigners, but their origins are different.”