It isn't quite "religion" as much as it is vast numbers of the poorly educated population using "religion" to support their highly conservative views. Religions, including the dominant one in Pakistan, have a component of social responsibility.
Pakistan too has a trend of decreasing birth rate with increasing economic power across the economic classes of people, even though all ascribe to the same religion.
Such a weird and untrue statement. Birth control is allowed in Islam. Maybe they don't trust them because of cases like the one where the CIA ran a fake vaccine program in order to collect DNA to help catch Bin Laden[0]. Or maybe it's because there isn't widespread access to healthcare. Or one of the other factors you are totally ignorant to
* doesn't see 'family planning' as increasing population
* has religious traditions incompatible with any interpretation of 'family planning'
If Pakistan has a strongly increasing population then it will be in good position to take advantage of depopulation in China and elsewhere.