"High fertility" refers to the ability of a person or a population to have a large number of babies or children. It means having a high rate of reproduction or being very fertile. Full definition
High fertility rates in areas of the developing world that can least cope put tremendous pressure on freshwater and sanitation needs and fuel economic and religious tensions. (scientificamerican.com)
Yet, there's a bundle of evidence showing that women's moods, behaviors, and interpersonal styles actually change during that small window of high fertility as well. (scienceofrelationships.com)
It is important to keep in mind that relatively low vaginal readings indicate high estrogen levels, which often indicates high fertility. (ovagraph.com)