Birth rate
The region of Sub-Saharan Africa has the highest birth rate in the world. As of 2016, Niger, Mali, Uganda, Zambia, and Burundi have the highest birth rates in the world. This is part of the fertility-income paradox, as these countries are very poor, and it may seem counter-intuitive for families there to have so many children. The inverse relationship between income and fertility has been termed a "demographic-economic "paradox"" by the notion that greater means would enable the production of more offspring as suggested by the influential Thomas Malthus.
Demographics of Bangladesh
Bangladesh has the highest population density in the world, excluding a handful of city-states and small countries with populations under 10 million, such as Malta and Hong Kong. The total fertility rate (TFR) has been reduced by more than two thirds since Independence. Current TFR in Bangladesh is 2.1 which means that women have 2.1 children on average in their lifetime. At this TFR and without migration, country's population will eventually be neither growing nor shrinking, once the top of its age pyramid fill in.
Most of the demographic statistics below are from the CIA World Factbook, unless otherwise indicated.