Birth rate
According to the CIA's "The World Factbook", the country with the highest birth rate is Niger at 6.49 children born per woman and the country with the lowest birth rate is Taiwan, at 1.13 children born per woman.
Infant mortality
Collecting the accurate statistics of infant mortality rate could be an issue in some rural communities in developing countries. In those communities, some other alternative methods for calculating infant mortality rate are emerged, for example, popular death reporting and household survey.
The country-to-country variation in child mortality rates is huge, and growing wider despite the progress. Among the world's roughly 200 nations, only Somalia showed no decrease in the under-5 mortality rate over the past two decades.The lowest rate in 2011 was in Singapore, which had 2.6 deaths of children under age 5 per 1,000 live births. The highest was in Sierra Leone, which had 185 child deaths per 1,000 births. The global rate is 51 deaths per 1,000 births. For the United States, the rate is eight per 1,000 births.