In 1925, the total fertility rate in the region of present-day Bangladesh was approximately 6.7 children per woman, meaning that the average woman born in Bangladesh at this time would have just under seven children over the course of her reproductive years. This rate would fall slowly in the first half of the 20th century, due to declines in child mortality rates, however, fertility would begin to rise in Bangladesh following the region’s partition into East Pakistan in 1947.
After peaking at just under seven children in the early 1970s, fertility would begin to rapidly decline in Bangladesh, during a period of extensive displacement from the 1971 Bangladesh genocide and the resulting war for independence, which contributed to political instability, lack of infrastructure and widespread poverty for much of the remainder of the century. As a result, the Bangladeshi fertility rate would decline to just over four children per woman by the end of military rule in the early 1990s. While the rate of decline has slowed in the years following the restoration of democratic government to the country, fertility has continued to drop into the 21st century as modernization, women's education and access to contraception improves. As a result, in 2020, it is estimated that the average woman born in Bangladesh will have just over two children over the course of her reproductive years, which is roughly replacement level fertility.