Pregnancies, intentions, and fertility behaviors during use of the Creighton Model FertilityCare System after initial intention to avoid pregnancy: Results from the Creighton Model effectiveness, intentions, behaviors assessment study
Shahpar Najmabadi, Chun-Pin Esther Chang, Kathy M. Rivet
Daniel Opoku Agyemang , Chun-Pin Chang, Christina A Porucznik, Joseph B Stanford
Department of Family and Preventive Medicine, Office of Cooperative Reproductive Health, Division of Public Health, Spencer Fox Eccles School of Medicine, University of Utah, Salt Lake City, United...
Division of Public Health, Department of Family and Preventive Medicine, University of Utah School of Medicine, and Huntsman Cancer Institute, Salt Lake City, UT, United States of America.
Creighton Couples Trying to Conceive Reached 88% Within 13 Cycles
This study followed 296 couples who charted to avoid pregnancy. Trying to conceive, 88.0% to 89.8% were pregnant within 13 cycles. 90 of 122 pregnancies were achieving-related: sex on fertile days. Correct use to avoid: 3 pregnancies in 220 cycles.
In cycles with the intention to conceive, 88.0% to 89.8% of couples were pregnant by 13 cycles, across every sensitivity scenario the researchers tested.
Some couples said they wanted to avoid but had fertile-day sex, which is achieving-related. Across all avoid-intent cycles the 13-cycle rate was 29.1% to 35.3%.
Under the strictest correct use to avoid, no sex on fertile or unclear days, there were 3 pregnancies in 220 cycles among 64 couples. The 13-cycle rate was 15.6%.
44% of cycles with strong intentions to avoid pregnancy included intercourse on potentially fertile days or on days of undetermined fertility status. 90 of the 122 pregnancies were classified as achieving-related.
In the adjusted analysis, baseline motivation and the wish to be pregnant within two years tracked more closely with pregnancy than a single cycle's intention.
Clinical Implications
These couples all began charting to avoid pregnancy, and over half of the women wanted a child within two years. In the cycles where they aimed for pregnancy, close to 9 in 10 conceived within about a year. Some couples said they wanted to avoid, then had sex on fertile days, which Creighton counts as achieving-related activity whatever a couple states. That behavior, not a failure to read the signs, is where the pregnancies came from.
Study Notes
A prospective cohort study in 17 Creighton Model centers in the United States and Canada. Researchers followed 296 couples for up to a year after they began charting to avoid pregnancy, covering 2,894 cycles. Rates are 13-cycle lifetable estimates, so few pregnancies in few cycles can yield a large percentage. The charts did not record the time of day of sex, which the method treats as fertile on some days.
RRM Context
The Creighton Model is a set way of charting cycle signs, mostly cervical mucus, to mark fertile and infertile days. Restorative reproductive medicine starts from what the cycle is doing, so this kind of body literacy is the ground the clinical work stands on. This study looked at how couples used the charting. It did not test a treatment. It does show that a charted cycle carries real information about when pregnancy is possible.
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
Knowledge of the fertile and infertile phases of the menstrual cycle can be applied to conceive or to avoid pregnancy. Fertility intentions and sexual behaviors during the fertile time may influence whether and when pregnancy occurs. The Creighton Model FertilityCare System (CrMS) is a specific system of fertility appreciation used to conceive or to avoid pregnancy. The objective of this paper is to report intentions, behaviors, and pregnancy rates during use of the CrMS among couples who initially intended to avoid pregnancy.Data and methodsWe analyzed a prospective cohort study conducted in 17 CrMS centers across the USA and Canada, following 296 couples for up to one year after onset of initial use of the CrMS to avoid pregnancy. Baseline data included demographics, motivations, and pregnancy intentions for each partner. Couples contributed 2894 menstrual cycles, most of which had data collected (by questionnaires and daily diary) on cycle-specific pregnancy intentions, days of potential fertility, and fertility behaviors. Pregnancies were prospectively actively ascertained.
Results
We found a high concordance (91%) in cycle pregnancy intentions between partners. However, 44% of cycles with strong intentions to avoid pregnancy included intercourse on potentially fertile days or days of undetermined fertility status. Across all sensitivity scenarios, cumulative 13-cycle pregnancy rates with cycle intention to conceive ranged from 88.0% to 89.8%, and cumulative 13-cycle pregnancy rates with cycle intention to avoid ranged from 29.1% to 35.3%. In multivariate analysis, baseline motivations and intentions for pregnancy within 2 years were strongly correlated with the likelihood of pregnancy, more so than cycle intentions.
Conclusion
The findings suggest that in some populations using natural family planning, baseline motivations and intentions may be more strongly related to pregnancy rates than cycle intentions. Our findings also highlight essential elements for evaluating correct use, including complete recording of intercourse and its timing.
Creighton Model FertilityCare System pregnancy avoidance, fertility intentions behaviors natural family planning, Stanford Najmabadi Creighton Model effectiveness study, CEIBA study Creighton Model prospective cohort, pregnancy rate intention avoid Creighton Model, cervical mucus monitoring fertility awareness method, cycle-specific pregnancy intentions partner concordance, natural family planning effectiveness real-world data, fertile day intercourse unintended pregnancy NFP, baseline motivation pregnancy prediction CrMS
PMID 40729325 40729325 DOI 10.1371/journal.pone.0328806 10.1371/journal.pone.0328806 Stanford et al. 2025, Stanford 2025
Cite this article
Stanford, J. B., Najmabadi, S., Chang, C. P. E., Agyemang, D. O., Rivet, K., & Porucznik, C. A. (2025). Pregnancies, intentions, and fertility behaviors during use of the Creighton Model FertilityCare System after initial intention to avoid pregnancy: Results from the Creighton Model effectiveness, intentions, behaviors assessment study. PloS one, 20(7), e0328806. https://doi.org/10.1371/journal.pone.0328806
Stanford JB, Najmabadi S, Chang CPE, Agyemang DO, Rivet K, Porucznik CA. Pregnancies, intentions, and fertility behaviors during use of the Creighton Model FertilityCare System after initial intention to avoid pregnancy: Results from the Creighton Model effectiveness, intentions, behaviors assessment study. PLoS One. 2025;20(7):e0328806. doi:10.1371/journal.pone.0328806
Stanford, J. B., et al. "Pregnancies, intentions, and fertility behaviors during use of the Creighton Model FertilityCare System after initial intention to avoid pregnancy: Results from the Creighton Model effectiveness, intentions, behaviors assessment study." PloS one, vol. 20, no. 7, 2025, pp. e0328806.
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