Hilgers, T. W., & Stanford, J. B. (1998). Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness. The Journal of reproductive medicine, 43(6), 495-502.
Hilgers TW, Stanford JB. Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness. J Reprod Med. 1998;43(6):495-502.
Hilgers, T. W., and J. B. Stanford. "Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness." The Journal of reproductive medicine, vol. 43, no. 6, 1998, pp. 495-502.
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Pope Paul VI Institute for the Study of Human Reproduction, Omaha, Nebraska.027jqx654
To evaluate the use effectiveness of Creighton Model (CrM) NaProEducation Technology for avoiding pregnancy.
Study Design
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.
Results
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.
Conclusion
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.
Minjeur M et al., 2026·Journal of Restorative Reproductive Medicine·Free to read
Infertility is a clinical condition that is recognized by the symptom of an inability to conceive through sexual intercourse or to sustain a pregnancy, with that symptom indicating underlying male and/or female pathology.
This definition of infertility was developed through a structured, consensus-informed process involving broad stakeholder engagement. Initially, multiple definitions currently used by various medical professional organizations were reviewed, and a definition document was drafted and submitted to the Board of Directors of the International Institute for Restorative Reproductive Medicine (IIRRM). All IIRRM members were invited to provide feedback on the draft. Approximately 2,500 individuals and 44 organizations from 92 countries were then invited to review the proposed document, representing clinical, scientific, patient, policy, and advocacy perspectives. Submitted comments were reviewed thematically, with suggested revisions evaluated for clarity, clinical relevance, inclusiveness, and consistency with contemporary restorative reproductive medicine. Following this review, 3 substantive changes, 18 minor changes, and 15 citation corrections were incorporated into the final draft which resulted in a revised definition intended to better reflect the medical, social, and practical realities of modern infertility evaluation and care. Final approval by the IIRRM Board of Directors was unanimous.
Kahn LG et al., 2026·JAMA Network Open·Free full text on PubMed Central
Increasing numbers of children are conceived using infertility treatment; concerns remain about potential effects on child neurodevelopment. To evaluate whether infertility treatment is associated with child neurodevelopment and whether such an association may be attributable to underlying subfecundity. DESIGN, SETTING, This cohort study was conducted among mother-child dyads in the National Institutes of Health Environmental Influences on Child Health Outcomes (ECHO) Cohort, with infants conceived between 1998 and 2022. Associations of subfecundity and infertility treatment with neurodevelopmental outcomes were assessed among children ages 2 to 10 years. Data were analyzed from May 14, 2025, to March 31, 2026. Subfecundity was defined as prior consultation for, treatment of, or diagnosis of infertility for either partner; at least 2 prior miscarriages; or ever having had unprotected heterosexual intercourse for 12 months without conceiving. Infertility treatment was categorized as in vitro fertilization (IVF) or non-IVF treatment. Harmonized caregiver responses to the Strengths and Difficulties Questionnaire and the Child Behavior Checklist yielded continuous raw scores for externalizing and internalizing problems. The total raw Social Responsiveness Scale (SRS) score quantified autism-like symptoms. Caregivers reported physician diagnosis of autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Among 15 382 mother-infant dyads, there were 14 191 unique maternal participants (mean [SD] age at delivery, 30.9 [5.33] years; 8780 parous participants [57.1%]). ASD and ADHD were diagnosed in 876 offspring (7.6%) and 819 offspring (7.1%), respectively. In generalized linear models, subfecundity was associated with higher externalizing problem and SRS scores among all pregnancies (externalizing problems: b = 0.47 [95% CI, 0.14-0.81]; SRS score: b = 1.08 [95% CI, 0.01-2.14]) and when restricted to natural conceptions (externalizing problems: b = 0.45 [95% CI, 0.07-0.83]; SRS score: b = 1.12 [95% CI, -0.09 to 2.34]). Offspring of parents with subfecundity had higher odds of ASD (overall: odds ratio [OR], 1.27 [95% CI, 1.03-1.57]; natural conceptions: OR, 1.31 [95% CI, 1.04-1.64]). Children conceived via non-IVF treatment had higher odds of ADHD compared with those conceived via natural conception with subfecundity (OR, 1.77 [95% CI, 1.16-2.68]) or without subfecundity (OR, 1.54 [95% CI, 1.05-2.25]). There were no significant associations for IVF treatment. In this large US cohort study, subfecundity was associated with elevated scores for caregiver-reported symptoms of behavioral problems and higher odds of ASD diagnosis, independent of infertility treatment. Non-IVF treatment was associated with ADHD, warranting further research into specific indications for treatment that may increase risk of offspring neurodevelopmental problems.
Stanford JB et al., 2026·Frontiers in Reproductive Health·Free full text on PubMed Central
Background The total fertility rate (TFR) in most developed countries has been declining for decades. In the United States (U.S.), the total fertility rate has remained below replacement level since 2007. Subfertility affects at least 15% of women or couples over their reproductive lifespan and contributes to reduced TFR. Restorative reproductive medicine (RRM) is a medically based approach to subfertility care that can be delivered in primary care settings to increase live birth rates. Objective To estimate the theoretical impact of use of RRM among subfertile couples in the United States. Methods We conducted a simulation study. Model inputs included the number of women of reproductive age in the United States by 5-year age groups; current age-specific and total fertility rates; the proportion of women in each age group with subfertility; estimated spontaneous live birth rates among women with subfertility; and age-specific crude live birth rates with RRM treatment. We evaluated fifteen scenarios including sensitivity analyses: two different varying assumptions for spontaneous conception (25% vs. 50%), two levels of RRM utilization among subfertile women (20% vs. 50%), three different estimates of the number of subfertile women who would be potentially eligible for RRM treatment, and 4 different levels of effectiveness (live birth) from RRM treatment. Results The baseline TFR in the United States was 1.77 during 2015-2019, and 13.5% of women ages 20-44 were estimated to have subfertility. In a conservative scenario (50% spontaneous births; 20% RRM utilization; married women trying to conceive for at least 12 months, 20.7% RRM live births), the TFR increased to 1.79, representing a 1.0% relative increase (absolute +0.02). In an optimistic scenario (25% spontaneous births; 50% RRM utilization; all subfertile women), the TFR increased to 2.02, a 14.5% relative increase (absolute +0.26), approaching replacement-level fertility. Conclusion Simulation results suggest that expanding access to RRM within primary care settings could meaningfully increase the U.S. TFR, by reducing unresolved subfertility. Realizing this potential would require policy and health system changes to address workforce capacity, insurance coverage, and equitable access. These findings underscore the potential contribution of non-IVF fertility care pathways in addressing population-level fertility decline.
Fehring RJ et al., 1994·J Obstet Gynecol Neonatal Nurs·Free to read
To determine the use effectiveness of the Creighton model ovulation method in avoiding and achieving pregnancy. Prospective, descriptive. A natural family planning clinic at a university nursing center. Records and charts from 242 couples who were taught the Creighton model. The sample represented 1,793 months of use of the model. Creighton model demographic forms and logbook. 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%. 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.
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 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.
Hilgers TW et al., 2004·The Medical and Surgical Practice of NaProTECHNOLOGY
Pregnancy achievement rates among couples using the CrMS to target fertile days are analyzed by cycle type, reproductive history, and duration of use, demonstrating the system's capacity to accommodate irregular and abnormal cycles without reducing its fertility-targeting utility. These data are foundational to NaProTECHNOLOGY's application in infertility management, establishing that the CrMS identifies fertile windows even in subfertile populations with disrupted cycle parameters.
Fertility Awareness › Effectiveness › Typical and Perfect Use · Restorative Reproductive Medicine › NaProTechnology › Program Outcomes
Thomas W Hilgers, Joseph B Stanford
Tom Hilgers, T Hilgers, Joe Stanford, Joey Stanford, J Stanford
PMID 9653695 9653695 Hilgers et al. 1998, Hilgers 1998
Cite this article
Hilgers, T. W., & Stanford, J. B. (1998). Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness. The Journal of reproductive medicine, 43(6), 495-502.
Hilgers TW, Stanford JB. Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness. J Reprod Med. 1998;43(6):495-502.
Hilgers, T. W., and J. B. Stanford. "Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness." The Journal of reproductive medicine, vol. 43, no. 6, 1998, pp. 495-502.
Keywords
Adult, Contraception/methods, Female, Health Education, Humans, Male, Natural Family Planning Methods, Ovulation Detection, Pregnancy, Prospective Studies, Schools, Medical