Fehring, R. J., Lawrence, D., & Philpot, C. (1994). Use effectiveness of the Creighton model ovulation method of natural family planning. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 23(4), 303-309. https://doi.org/10.1111/j.1552-6909.1994.tb01881.x
Fehring RJ, Lawrence D, Philpot C. Use effectiveness of the Creighton model ovulation method of natural family planning. J Obstet Gynecol Neonatal Nurs. 1994;23(4):303-309. doi:10.1111/j.1552-6909.1994.tb01881.x
Fehring, R. J., et al. "Use effectiveness of the Creighton model ovulation method of natural family planning." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 23, no. 4, 1994, pp. 303-309.
Creighton Model was 98.0% use effective at avoiding pregnancy
The Creighton Model was 98.0% use effective at avoiding pregnancy over 12 months, a prospective descriptive study found. It followed 242 couples taught the method at a university nursing clinic. Among those couples, use effectiveness at achieving pregnancy was 24.4%. The study estimated a continuation rate of 78.0% at 12 months.
Key Findings
Over 12 months, the Creighton Model reached 98.8% method effectiveness and 98.0% use effectiveness for avoiding pregnancy, per 100 couples.
Use effectiveness at achieving pregnancy was 13.6 per 100 couples at 6 months of use and 24.4 per 100 couples at 12 months.
Among the 242 couples, 65 pregnancies occurred within 12 months, and most were achieving related.
The study estimated a continuation rate of 78.0% at 12 months of use.
Of 323 enrolled couples, 242 entered the analysis; 80.2% of the female partners were Roman Catholic and 93.0% were white.
Interpretation
The study is a prospective descriptive analysis of records from one university clinic. It has no comparison group. Life-table methods produced the rates. The authors labeled a pregnancy achieving related when a couple using the method to avoid pregnancy knowingly had intercourse on a fertile day. A World Health Organization trial classified such pregnancies as avoidance failures. Under that reading, this study's 12-month rate would be 12.8 per 100 couples, which the authors call tenuous. The sample was small and homogeneous, a limitation the authors list. They conclude that effectiveness depends on qualified teachers.
RRM Context
Fertility awareness-based methods rely on the body's own fertility signs. The Creighton Model uses cervical mucus to mark fertile days. One chart serves couples avoiding or achieving pregnancy. The teachers here finished a one-year training program, accredited by the American Academy of Natural Family Planning. A 1991 meta-analysis cited in the paper found that natural family planning studies used different methods and pregnancy classifications. That limits comparison between them.
Our editorial summary of this paper, not the article's abstract.
Abstract
Objective
To determine the use effectiveness of the Creighton model ovulation method in avoiding and achieving pregnancy.
Design
Prospective, descriptive.
Setting
A natural family planning clinic at a university nursing center.
Participants
Records and charts from 242 couples who were taught the Creighton model. The sample represented 1,793 months of use of the model.
Main Outcome Measures
Creighton model demographic forms and logbook.
Results
At 12 months of use, the Creighton model was 98.8% method effective and 98.0% use effective in avoiding pregnancy. It was 24.4% use effective in achieving pregnancy. The continuation rate for the sample at 12 months of use was 78.0%.
Conclusion
The Creighton model is an effective method of family planning when used to avoid or achieve pregnancy. However, its effectiveness depends on its being taught by qualified teachers. The effectiveness rate of the Creighton model is based on the assumption that if couples knowingly use the female partner's days of fertility for genital intercourse, they are using the method to achieve pregnancy.
Bouchard TP et al., 2026·Journal of ovarian research·Free to read
Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the reproductive hormones in various clinical circumstances and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. A total of 57 women (ages 22-51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovarian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome/polyendocrine metabolic ovarian syndrome (PCOS/PMOS) group showed high luteal pregnanediol glucuronide. The perimenopause group had significantly higher luteinizing hormone values throughout the whole cycle. The fertile window hormone thresholds vary depending on a woman's specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.
Malliou-Becher MN et al., 2026·Human reproduction (Oxford, England)
What are the variations in ovulation time and menstrual cycle characteristics among and within various individuals over the course of 12 menstrual cycles? There are considerable variations in both cycle length and ovulation time, with pronounced intra-individual variability over a 12-cycle observation period. Although it is commonly believed that healthy women have regular cycles with a predictable mid-cycle ovulation, more recent research shows a significant variation in cycle length and ovulation time. Previous studies have focused only on cycle length, often excluding cycles outside the 25-35-day range, thus limiting the understanding of natural variation; they have also lacked precise ovulation diagnostics or included small sample sizes, making it difficult to capture the full scope of cycle and ovulation variability. Similarly, a recent big data study, while valuable, was limited by a self-selected group and the absence of accurate ovulation diagnostics, reducing its generalizability. STUDY DESIGN, SIZE, This study was designed as a prospective long-term observational study, which involved collecting data from 1923 women with a total of 43 999 menstrual cycles from January 1985 to July 2019. After fulfilling the inclusion criteria, the main group consisted of 1051 women, all of whom contributed data for 12 cycles (12 612 cycles), including 420 conception cycles. PARTICIPANTS/MATERIALS, SETTING, Participants in the study were between 18 and 44 years of age at study entry and did not take any reproductive hormones. Women who were postpartum, breastfeeding, amenorrheic, or within a 3-month period after stopping hormonal contraception were excluded. Participants agreed to keep cycle records according to the symptothermal method, 'Sensiplan'. Ovulation time was determined using an evidence-based algorithm based on evaluating cervical mucus patterns and basal body temperature shifts, with ovulation time defined as the day before the temperature rise. Data analysis was descriptive, using absolute and relative frequencies, standard deviation, percentiles, and ranges. Age dependency was assessed using unpaired sample t-tests and one-way ANOVA. Linear regression was used to assess long-term trends. MAIN In 62.4% of women, cycle lengths varied by 1 week or more within 12 cycles. Accordingly, the time of ovulation varied by 1 week or more within 12 cycles in 54.8% of women, with 96.5% experiencing fluctuations of 4 days or more over the 12 months. The median spontaneous cycle length was 28 days, with a mean of 29.66 days (SD = 7.55). Only 52.7% of women consistently had cycle lengths between 23 and 35 days across all 12 cycles. Ovulation occurred most frequently between Days 12 and 16, with almost half of conceptions (45.7%) occurring after Day 16. A one-way analysis of variance revealed a significant reduction in mean cycle length with increasing age (P < 0.001), showing the shortest median cycle length of 27 days being in women aged 40-44 years. Age also impacted ovulation time, with women aged 35-39 years showing more stable ovulation patterns compared to younger women. Over the 34-year study period, average cycle length increased slightly but significantly (β = 0.0161, P = 0.0306), corresponding to approximately half a day. Intra-individual variability also showed a slight, but non-significant, upward trend (β = 0.0262, P = 0.2173). LIMITATIONS, Comorbidities such as hyperprolactinemia, obesity, and PCOS were not systematically excluded. However, by including only women with at least 12 cycles, the study largely avoided severe hormonal disorders. This study highlights the considerable individual variation of ovulation time and cycle length over 12 menstrual cycles. These findings contribute to a better understanding of fertility awareness, and highlight the implications for family planning and reproductive health management. STUDY FUNDING/COMPETING INTEREST(S): The authors declare no conflicts of interest. No funding was provided. N/A.
Bouchard TP et al., 2025·Preprints.org·Free to read
Background/Objectives: Quantitative urine monitors are increasingly being used for a personalized approach to improve menstrual cycle knowledge and to manage fertility. Although several studies have evaluated urine fertility monitors in regular cycles, there is limited research in the use of quantitative monitors in reproductive disorders, such as polycystic ovarian syndrome (PCOS). Urine hormone data was collected with the Mira monitor from 20 participants, 10 of whom had PCOS and a matched group who had regular cycles. The main aim of this study was to evaluate the levels of luteinizing hormone (LH), estrone-3-glucuronide (E13G), and pregnanediol glucuronide (PDG) in PCOS menstrual cycles compared to regular cycles. Women with PCOS had higher BMI than regular cycling women (p=0.02). PCOS cycles were longer (p<0.05), peak day was later in the menstrual cycle (p<0.001), and luteal length was shorter (p < 0.01) compared to regular cycles. In whole cycle comparisons, E13G was found to be lower in PCOS cycles (p<0.01) and PDG was found to be higher in PCOS cycles (p<0.05). E13G was also lower in the follicular phase of and late luteal phase of PCOS cycles (p<0.00001). The results of this study demonstrate the feasibility of detecting hormonal differences in PCOS compared to regular cycles with at-home measurements with the Mira monitor. The metabolic dysregulation of PCOS is a possible factor in these hormone changes. Larger studies with different sub-types of PCOS will be needed to further clarify these changes and to understand the pathophysiology behind these hormonal changes.
Manhart MD et al., 2025·Linacre Q·Free full text on PubMed Central
A one-day meeting was held as a pre-conference to the Catholic Medical Association Annual Educational event in 2024. A panel of eighteen physicians, scientists, and researchers involved in NFP work was convened to review the available evidence in four topical areas: (i) evidence for effectiveness of NFP methods to postpone and achieve pregnancy, (ii) evidence for effectiveness in the postpartum and perimenopause transition periods, (iii) evaluate the current state of technology in NFP (specifically app and quantitative hormone monitoring), and (iv) evidence examining the impact of NFP on marital relations. In each topical area, the panel worked to reach a consensus opinion on the currently available evidence and identified priorities for further research. Results from these discussions and a set of priorities for further work are presented here.
An expert panel was convened to review the current evidence supporting use of NFP in various settings, utilization of new technology, and the impact of NFP on marital dynamics. Results from these discussions and a set of priorities for further work are presented here.
To evaluate the use effectiveness of Creighton Model (CrM) NaProEducation Technology for avoiding pregnancy. CrM is a medical model of natural procreation education that is a fully standardized modification of the Billings ovulation method. This system has been used as a means to avoid pregnancy and has been prospectively evaluated in five use effectiveness studies. A prospective life-table analysis of the five studies (meta-analysis) was undertaken, yielding both net and gross rates. Discontinuation rates were also calculated. These studies were conducted at CrM centers in Omaha, St. Louis, Wichita, Houston, and Milwaukee. A total of 1,876 couples used CrM NET for a total of 17,130.0 couple months of use. The method and use effectiveness rates for avoiding pregnancy were 99.5 and 96.8 at the 12th ordinal month and 99.5 and 96.4 at the 18th ordinal month, respectively. The discontinuation rate was 11.3% at the 12th ordinal month and 12.1% at the 18th ordinal month. CrM is highly effective as a means of avoiding pregnancy in both its method and use effectiveness. The method effectiveness has remained stable over the years of the studies, but the use effectiveness for avoiding pregnancy appears to have improved over the study period.
To evaluate pregnancy probabilities during use of the Creighton Model Fertility Care System (CrMS). Couples who began use of the CrMS were entered into this observational cohort study. Follow-up included detailed reviews of use of the CrMS. Pregnancy probabilities were calculated with both net and gross life-table analysis through 18 months. A natural family planning service delivery program based at an urban hospital in Houston, Tex. A group of 701 couples who received instruction in the CrMS were entered into the study. Most couples (93%) were engaged or married. Most women were white (83%), between the ages of 20 and 34 years (88%), and college graduates (58%). Pregnancies were classified based on a detailed evaluation involving the pregnant woman (usually with her partner). At 12 months, the following net pregnancy probabilities were found per 100 couples: method-related pregnancies, 0.14; pregnancies caused by user and/or teacher error, 2.72; pregnancies caused by achieving-related behavior (genital contact during a time known to be fertile), 12.84; unresolved pregnancies, 1.43; and total pregnancies, 17.12. Pregnancy probabilities were similar when stratified by the following reproductive categories: uncomplicated regular cycles, long cycles, discontinuing oral contraceptives, breastfeeding, and other. Pregnancy probabilities of the CrMS compare favorably with those of other methods of family planning. Most pregnancies result from genital contact during a known fertile time. Women need not have regular cycles to use the CrMS successfully.
Stanford JB, 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
Methodologically rigorous effectiveness data for the CrMS are presented, including method-effectiveness and use-effectiveness rates for pregnancy avoidance drawn from prospective cohort studies, demonstrating rates comparable to or exceeding hormonal contraception. Standardized outcome measurement is necessary to establish the CrMS's scientific credibility and to provide practitioners and patients with accurate, evidence-based counseling on system performance.
Stanford JB et al., 2025·PLoS One·Free full text on PubMed Central
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 methods We 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. 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. 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.
Fertility Awareness › Effectiveness › Typical and Perfect Use · Restorative Reproductive Medicine › NaProTechnology › Program Outcomes
Richard J Fehring
Rick Fehring, Dick Fehring, Rich Fehring, R Fehring
PMID 8057183 8057183 DOI 10.1111/j.1552-6909.1994.tb01881.x 10.1111/j.1552-6909.1994.tb01881.x Fehring et al. 1994, Fehring 1994
Cite this article
Fehring, R. J., Lawrence, D., & Philpot, C. (1994). Use effectiveness of the Creighton model ovulation method of natural family planning. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 23(4), 303-309. https://doi.org/10.1111/j.1552-6909.1994.tb01881.x
Fehring RJ, Lawrence D, Philpot C. Use effectiveness of the Creighton model ovulation method of natural family planning. J Obstet Gynecol Neonatal Nurs. 1994;23(4):303-309. doi:10.1111/j.1552-6909.1994.tb01881.x
Fehring, R. J., et al. "Use effectiveness of the Creighton model ovulation method of natural family planning." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 23, no. 4, 1994, pp. 303-309.
Keywords
Adult, Female, Humans, Life Tables, Male, Models, Educational, Natural Family Planning Methods, Nursing Care/methods, Ovulation, Program Evaluation, Prospective Studies, Sex Education/methods, Americas, Cervical Mucus Method, Contraception, Contraception Continuation, Contraceptive Effectiveness, Contraceptive Usage, Delivery Of Health Care, Developed Countries, Education, Family Planning, Family Planning Training, Family Planning, Behavioral Methods, Health, Health Personnel, Literature Review, Natural Family Planning, North America, Northern America, Nurses, Prospective Studies, Research Report, Studies, Training Programs, United States, Use-effectiveness, Wisconsin
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