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.
Rivne Oblast
Rivne is one of the regions with the highest birth rate in all of Ukraine. The heavy rural (about two thirds of the population is rural) and ethnic Ukrainian (close to 95%) composition of the population might be responsible for this. However the birth rate is not uniform across Rivne, with raions like Ostroh having extremely low birth rates (9.7 per 1000) and other raions like Rokytnivskyi having extremely high birth rates (24.0 per 1000).