the number of live births occurring in a year per 1000 women of child-bearing age (usually 15 to 44 years). A less reliable measure of fertility can be obtained from the live birth rate (the number of live births per 1000 of the population) or the natural increase (the excess of live births over deaths). More rarely quoted are the gross reproduction rate (the rate at which the child-bearing female population is reproducing itself) and the net reproduction rate, which takes into account female mortality before the age of reproduction.
* * *
a measure of fertility in a defined population over a specified period of time, usually one year; particularly the general fertility r., but also including more specific rates such as those for females of a given parity or a particular decade in age or that describing the completed rate for females who have finished childbearing.Medical dictionary. 2011.