Chapter 15: Scientific Foundations of the CrMS

This chapter reviews the scientific basis of the CREIGHTON MODEL FertilityCare™ System (CrMS), which it traces to a 1976 independent investigation of the Billings Ovulation Method at St. Louis University School of Medicine. Hilgers presents the cervix as a “biological valve” that allows sperm entry at certain times of the cycle and bars it at others, and reviews fern and channel studies, the work of Professor Erik Odeblad on cervical mucus types, sperm penetration studies, and hormonal, ultrasound, and vaginal cytology correlations with the Peak Day. In an ultrasound study of women with infertility (n=33), follicular rupture showed a close association with the Peak Day within a range of P-2 to P+3, and the chapter states that the study has since been expanded to 432 cycles with the same results. The chapter also presents a mucus observation survey of 130 women, statistical parameters from 600 cycles, client evaluations of the teaching system, and a five-study meta-analysis of 1,876 couples in which the 5-study composite method effectiveness to avoid pregnancy at the 12th ordinal month was 99.5.