This first Spanish edition of the "best book on the subject" gives specific instruction on the use of two methods of family planning: Natural Family Planning and the Fertility Awareness Method. These methods give couples natural choices: **To avoid pregnancy, you can determine when you are infertile and have sexual intercourse without conceiving. **To become pregnant, you can track the days of the month when you are most fertile and have intercourse when you are most likely to conceive. Women with any kind of heart risk, especially those who smoke, are especially endangered by the pill. This book offers an alternative. These safe non-invasive techniques have no side effects and carry no danger of toxic infection or cancer. They can be used by themselves or combined with other contraception methods. This book allows couples to be secure in their lovemaking and in control of their sexual well-being. The authors, experts in fertility awareness, completely revised and updated this book, due to be published in English in early 2003. The new material includes several new examples of natural birth control and the fertility awareness method, with illustrations. The book contains helpful case studies, useful charts and illustrations, and is written in an accessible style.