Fecundity

n. productiveness, ability to bear young (in female animals); fertility, fruitfulness

Fecundity, derived from the word , generally refers to the ability to reproduce. In biology and demography, fecundity is the potential reproductive capacity of an organism or population, measured by the number of gametes (eggs), seed set or asexual propagules. Fecundity is under both genetic and environmental control, and is the major measure of fitness. Fecundation is another term for fertilisation.
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Fecundity /fe·cun·di·ty/ 1. in demography, the physiological ability to reproduce, as opposed to fertility. 2. [more]Fecundity - Community and Resources

Noun
1. the intellectual fruitfulness of a creative imagination
(synonym) fruitfulness
(hypernym) creativity, creativeness, creative thinking
2. the state of being fertile; capable of producing offspring
(synonym) fertility
(hypernym) physiological state, physiological condition
(attribute) fertile
3. the quality of something that causes or assists healthy growth
(synonym) fruitfulness
(hypernym) quality
(hyponym) richness, prolificacy, fertility

The ability to have children, usually lots of them with ease.