Chapter 9: Basic CrMS Instructions

This chapter presents the basic instructions of the CREIGHTON MODEL System (CrMS), which it describes as a system of both achieving and avoiding pregnancy, together with definitions such as the Peak Day, the last day of any mucus discharge that is clear, stretchy, or lubricative. The instructions define the days of fertility, which include the menstrual flow and the days from the beginning of the mucus until three full days past the Peak Day, and the dry days that are used to avoid pregnancy. Hilgers also describes the seminal fluid instruction, which the chapter states should not be viewed as contraceptive, and the instruction to treat any time of doubt as Peak fertility followed by a count of three days. The chapter reports that in its studies of 65 hormonally normal menstrual cycles ovulation occurred on average on the Peak Day, and it cites a preliminary survey of 50 pregnancies in which over 75 percent of couples of normal fertility conceived in the first cycle in which they used the days of fertility.