The Creighton Model was developed by Thomas Hilgers, the founder and director of the Pope Paul VI Institute.
This model, like the Billings ovulation method, is based on observations of cervical mucus to track fertility.
[2] The Billingses issued a paper refuting the claim that the CrMS represents a standardization of the BOM.
The typical-use failure rate, representing the fraction of couples using this method that actually had an unintended pregnancy, is reported as 3.2%.
[5][6][7] In the larger of these three studies, 75% of couples trying to conceive received additional hormonal stimulation such as clomiphene.