The trend began when the East Limburg hospital in Genk announced it was opening its own sperm bank for donations from locals. The hospital treats between 400 and 500 women every year with artificial insemination by donor (AID), and until now has been using donor sperm imported from Denmark.

However, according to fertility specialist Willem Ombelet, Danish donations don’t reflect the ethnic variety of the population of Limburg, and Genk in particular, which owes its diversity to the many immigrants who came to work in the coal mines. “For example a Turkish couple wants a baby who resembles them,” Dr Ombelet explained to De Standaard.

Donations will start in February from men aged 21 to 45, and donors accepted after screening will receive a fee of €50 to €85.

In Leuven, meanwhile, they prefer donations from staff and students at the university hospital, which is facing a “permanent shortage” of sperm donors. The university was responding to reports that samples nearly doubled between 2010 and 2011 to more than 19,000.

“Would that it were true,” lamented Professor Thomas D’Hooghe, coordinator of the fertility centre, on VRT radio. “But the reality is the opposite.” The centre promises to organise “more extensive promotion”. Leuven pays donors €50.

It will surprise no-one, then, to learn that the hospital of the Free University of Brussels (VUB) is also urgently looking for sperm donors. Professor Herman Tournaye explained that the confusion over the numbers of donations comes about because they include sperm frozen for other purposes than AID: for example, cancer patients who freeze a sample of their sperm before starting a course of chemotherapy. Those samples, he said, are not available for AID treatments.

The hospital pays €75 for a donation, but money is not the main reason people contribute, Tournaye said. “Most just want to help someone.”