The decline of the birth rate is visible in many Muslim countries, including Algeria, Egypt, Iran, Jordan, Lebanon, Tunisia and Turkey. Muslim birth rate decrease in Iran is one of the greatest records in history. There are many more Muslim countries with a birth rate decrease of 60% or more: Albania, Algeria, Bangladesh, Kuwait, Libya, Oman, Qatar, Tunisia, and the United Arab Emirates. A Muslim woman has today 2.6 less babies than her mother, which is a faster decline than worldwide average.
Extrapolation of the statistics show that Muslim growth rate will go down. A stable population needs a birth rate of 2.1 children. That means that the Muslim population will decrease both relative and absolute. It also means that it is the main reason that Islam is a fast dying religion. Unlike Christianity, Islam is not able to grow much by conversion, see next paragraph.
It's good to see a conservative Evangelical site like this one acknowledging the often missed point that the global Muslim birthrate is declining. A lot of Christian sites spout the myth that Muslims will take over the west through having a supposedly higher birthrate.