<Tr> <Th> Weight gain </Th> <Td> No </Td> </Tr> <Tr> <Th> Benefits </Th> <Td> Low direct cost; no side effects; in accord with Catholic teachings; may be used to aid pregnancy achievement </Td> </Tr> <P> The Creighton Model FertilityCare System (Creighton Model, FertilityCare, CrMS) is a form of natural family planning which involves identifying the fertile period during a woman's menstrual cycle . The Creighton Model was developed by Dr 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 . Creighton can be used for both avoiding pregnancy and achieving pregnancy . </P> <P> Hilgers describes the Creighton Model as being based on "a standardized modification of the Billings ovulation method", which was developed by John and Evelyn Billings in the 1960s . The Billingses issued a paper refuting the claim that the CrMS represents a standardization of the BOM . They are two different methods and should not be seen as interchangeable . </P>

What is the creighton method of birth control
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