Birth rate
As of 2017, Niger has the highest birth rate in the world with 49.443 per thousand people. 
Japan has one of the lowest birth rates in the world with 8 per thousand people.
While in Japan there are 126 million people and in Niger 21 million, both countries had around 1 million babies born in 2016.
Sex-selective abortion
Sex-selective abortion affects the human sex ratio—the relative number of males to females in a given age group, with China and India, the two most populous countries of the world, having unbalanced gender ratios. Studies and reports focusing on sex-selective abortion are predominantly statistical; they assume that birth sex ratio—the overall ratio of boys and girls at birth for a regional population, is an indicator of sex-selective abortion. This assumption has been questioned by some scholars.