INcontext have produced a helpful fact-check in response to the popular YouTube video, 'Muslim Demographics'.

Here are the main points to take away:

• Population growth in EU countries has been primarily driven by immigration, but the statistic includes all immigrants to EU countries, not just Muslims
   
• Muslims do not have fantastically high fertility rates: even in Algeria and Morocco, the two nations which send the largest numbers of Muslim immigrants to France, the fertility rate was 2.38 in 2008
   
• The Muslim population of Great Britain has grown, but not by 3000%, as the 1981 census did not survey respondents’ religious beliefs, on which the starting figure of 82,000 was based
   
• Muslim women in the Netherlands could not have accounted for '50% of all newborns', as they would have to be giving birth, on average, to about 14 to 16 times as many babies each as non-Muslim women
   
• The Belgian office of statistics points to a 2008 study which suggests the Muslim population  is 6%, so unlikely that it could account for 50% of births, as above
   
• The German government was misquoted as stating that it believed that Germany will become a Muslim state, although it is true that its population is in decline

Read the INcontext article in full, with detailed research from Snope and the Richard Knight at the BBC.