The Creighton Model FertilityCare System
A standardized cervical mucus charting system taught one-on-one by trained instructors. Creighton uses a defined vocabulary and stamp system so observations can be compared consistently between users and across time.
Source
Stanford et al., Creighton Model pregnancy probabilities, 1999.
Full citation
Stanford JB, Lemaire JC, Thurman PB. Pregnancy probabilities during use of the Creighton Model Fertility Care System. 1999.
How to read these numbers
Perfect use describes pregnancies per 100 women per year when the method is followed exactly as taught. Typical use describes pregnancies per 100 women per year across all users in a study, including cycles where the rules were not followed perfectly. Numbers come from specific published studies of specific populations and instruction settings; they are not guarantees for any individual. Methodology, sample size, and how a study defines a pregnancy or a cycle of use all affect the result, so figures from different methods are not always directly comparable.
This page is educational and is not medical advice. For decisions about contraception, fertility, or reproductive health, talk with a qualified clinician. See the medical disclaimer for details.
Before choosing a method
Before comparing method names, it helps to understand how NFP works, how method rules are learned, and how effectiveness claims should be read.
The Creighton Model FertilityCare System is a standardized way of observing and recording cervical mucus across the menstrual cycle. It is taught one-on-one by trained instructors and uses a defined chart so observations can be compared consistently. People use it for both avoiding and achieving pregnancy, and some clinicians use Creighton charts as part of broader reproductive health evaluation.
The system is more than a personal habit of charting. It defines what to observe, how to describe it, and how to mark it on a standardized chart, which is part of why it has been studied as a defined method.
What this method is
Creighton is a defined system. Observations follow a specific sequence and use specific terms (for example, descriptions of mucus length, consistency, and color), and they are recorded on a chart that looks the same across users and instructors. That consistency is what makes Creighton a method rather than a personal practice of charting.
What this method observes
Cervical mucus is the central signal. Users observe sensation and appearance throughout the day and assign each observation a description from the standardized vocabulary. The chart then shows when fertile-type signs appear and when they close, which the rules use to identify potentially fertile and infertile days.
How it generally works
Users are taught the observation routine and the chart by a trained practitioner over a series of follow-up sessions. Each session reviews the chart and refines the user's interpretation. Charts can be used to identify the fertile window for either avoiding or achieving pregnancy.
Who it may fit
- People who want a standardized chart and the same vocabulary across time.
- People who value one-on-one instruction with follow-up sessions.
- People who like the idea of a chart that a clinician familiar with the system can also read.
Who may need extra support
- People in postpartum, breastfeeding, or perimenopause, where mucus patterns can shift and additional instruction is usually helpful.
- People with conditions that affect cervical fluid or cycle regularity.
- People who would benefit from an additional, more objective hormonal signal alongside mucus.
What this method does not guarantee
No fertility awareness based method guarantees that pregnancy will not occur. Charting can flag patterns that may be worth discussing with a clinician, but it does not by itself diagnose medical conditions. Some clinical applications built on top of Creighton charting (such as NaProTechnology) sit outside what method-only research directly evaluates and should be assessed on their own evidence.
Instruction and learning considerations
Instruction is central. The standardized vocabulary, the chart format, and the follow-up sessions are all part of how the method is supposed to be learned. Self-teaching from materials alone is not equivalent to the instructor-led experience described in the published research.
Misconceptions worth clearing up
- Creighton charting does not diagnose disease on its own.
- It is not the same as the rhythm method, and not the same as a calendar app.
- A clean chart does not prove fertility is normal in a clinical sense, and a complicated chart does not prove illness; both call for clinical interpretation when concerns arise.
- Creighton and NaProTechnology are related but distinct, and statements about clinical outcomes from one cannot be transferred uncritically to the other.
Related research and reading
- Creighton charting research, /research/creighton-charting
- Cervical mucus, /glossary/cervical-mucus
- Can I use NFP with irregular cycles, /questions/can-i-use-nfp-with-irregular-cycles
- Do I need a certified instructor, /questions/do-i-need-a-certified-instructor
- Which method should I start with, /questions/which-method-should-i-start-with
- The science behind NFP, /science
- Browse all methods, /methods
Perfect-use checklist
What perfect use of the Creighton method assumes.
The published perfect-use number for this method describes couples who behaved a specific way during a specific study. This list summarises those behaviors so the number is read in context.
Source context. Behaviors assumed in the Creighton Model effectiveness research, including Stanford et al. 1999.
- Taught one-on-one by a certified Creighton FertilityCare practitioner, across the standard sequence of follow-up sessions.
- Observe cervical mucus at every bathroom visit, not just at one set time.
- Chart each observation using the Creighton vocabulary and stamps the same day.
- Identify the Peak Day according to the system's defined criteria.
- Treat any day with fertile-type mucus or any unusual bleeding as fertile.
- On days the rules mark fertile, abstain as the couple has agreed in advance.
- Apply the system's post-Peak rules exactly as taught to confirm the close of the fertile window.
- Bring the chart to scheduled follow-ups so the practitioner can correct interpretation early.
Pregnancy probability numbers describe couples who completed Creighton instruction with a trained practitioner. Casual mucus-watching is not the same protocol.
Educational summary, not individualized medical advice. For decisions about your body or your cycle, talk with a clinician or a certified instructor. See the medical disclaimer.
Reading the checklist
How to interpret perfect use.
What does perfect use actually mean?
Perfect use is a research category, not a personality test. It describes cycles where the couple followed every rule of the method exactly as taught for the entire study period. Researchers count a cycle as perfect use only when the charting, the timing, and the abstinence or barrier choices all matched the protocol. Anything else gets counted under typical use.
Why do real-world results often differ from perfect use?
Daily life adds variables a study cannot control. People travel, get sick, sleep poorly, miss an observation, or interpret a borderline sign in their own way. A couple may also choose to use a fertile day knowing the risk. None of that is failure of the method itself; it is the gap between an ideal protocol and lived behavior, which is exactly what the typical-use number captures.
Is perfect use realistic for most couples?
Many couples reach perfect use for stretches of time, especially after working with a certified instructor and settling into a routine. Sustaining it across years, life stages, and unusual cycles is harder. The honest read is that perfect use shows what the method can do when followed exactly, and typical use shows what tends to happen across a broad population.
How should I use this checklist?
Treat it as context for the published number, not as a personal grading rubric. If most items match how you plan to learn and chart, the perfect-use figure is a reasonable upper bound for your situation. If several items do not match, the typical-use figure is closer to what to expect. For decisions specific to your body, talk with a clinician or a certified instructor.
Sources referenced
Continue reading
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billings
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can i use nfp with irregular cycles
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do i need a certified instructor
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which method should i start with
Research
creighton charting
Glossary
Cervical Mucus
Glossary
Fertile Window
Glossary
Ovulation
Glossary
Fertility Awareness Method (FAM)
Glossary
Postpartum
Glossary
Perimenopause
Effectiveness FAQ
How effective is the Creighton method?
Quick answers using the numbers from this method's primary published study, with links to the full comparison.
See the full effectiveness comparisonHow effective is the Creighton method?
Published studies report 99.5% perfect-use effectiveness and 96.8% typical-use effectiveness for Creighton at one year. Source: Stanford et al., Creighton Model pregnancy probabilities, 1999.
What is the perfect-use effectiveness of Creighton?
99.5%. Perfect use means the method's rules were followed on every applicable day, as defined in the published study.
What is the typical-use effectiveness of Creighton?
96.8%. Typical use includes everyone in the study, including users who skipped observations or had intercourse during the fertile window.
Is Creighton as effective as hormonal birth control?
On perfect use, Creighton reports 99.5%, which is in the same range as hormonal methods such as the pill (about 99 percent perfect use). Typical-use numbers depend on the population, instruction, and how the study defined unintended pregnancy.
Other methods