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The methods of Natural Family Planning are based on scientific research about women's menstrual cycles, the signs of female fertility which are related to the event of ovulation, and the "fertile window" which takes into account how long a man's sperm can live in a woman's body.
Over a century ago, scientists discovered cyclic changes in a woman's cervical fluid (or "mucus") and their relation to ovulation. In the 1920s, scientists identified the temperature rise ("basal body temperature" or BBT) that signals ovulation. But it wasn't until the 1950s that scientists developed programs to teach others how to observe and interpret these fertility signs. Today, ongoing research continues to refine the methods of NFP. Here we present both classic and current NFP research.
Learn more about the following topics . . .
Human Reproduction and The Signs of Fertility
Cervical Mucus Method
Other Natural Approaches
"Natural Family Planning: A Review," Hanna Klaus, MD
This article provides a review of the classic scientific research behind the various methods of NFP.
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