Factors influencing the choice to use modern natural family planning

Definition of Infertility and Indications for Fertility Evaluation: Consensus Document

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.

Subfecundity, Infertility Treatment, and Child Neurodevelopment

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.

Potential increase of the U.S. total fertility rate resulting from restorative treatment of unresolved subfertility: a simulation study

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.

Restorative Reproductive Medicine Restricting Access to Care

Minjeur M et al., 2026 · JAMA

Interest in natural family planning among female family practice patients

Lemaire JC et al., 1994 · Fam Pract Res J

Although modern methods of natural family planning (NFP) are effective both to avoid and to achieve pregnancy, relatively few women use these methods. It is not known whether this is due primarily to lack of interest or to other factors. We therefore explored the level of interest in NFP among female family practice patients. We mailed information about NFP to 400 female patients between ages 21 and 42 and conducted follow-up interviews by telephone. We excluded 162 women for whom we could not obtain accurate addresses or phone numbers, 68 women we could not reach by telephone, 67 women who were not currently at risk of pregnancy, and 15 women for other reasons. Twenty-eight women refused to participate in the study. Sixty women completed telephone interviews. Forty-three percent of respondents (n = 60) were interested in learning more about NFP, 24% said they were likely to use NFP to avoid pregnancy, and 32% were likely to use NFP to achieve pregnancy. Younger women and women who were Christian but not Catholic and not of a major Protestant denomination were more interested in NFP. Some female family practice patients are interested in learning and using NFP.

Use of Natural Family Planning (NFP) and Its Effect on Couple Relationships and Sexual Satisfaction: A Multi-Country Survey of NFP Users from US and Europe

Unseld M et al., 2017 · Front Public Health · Free full text on PubMed Central

Birth control is a persistent global health concern. Natural family planning (NFP) comprises methods to achieve or avoid pregnancy independent of mechanical or pharmacological intervention. The sympto-thermal method (STM) of NFP employs daily observation of cervical fluids and measurement of basal body temperature. This multi-country study was undertaken to describe the characteristics of STM users, understand their perceptions of NFP, and its perceived impact on relationships. Questionnaires for women and men were developed in German and translated to English, Polish, Italian, Czech, and Slovak by native speakers. A total of 2,560 respondents completed the online questionnaire (37.4% response). Participants were married (89%) and well educated, and their self-perceived financial status was described as "good" or "very good" by 65% of the respondents. Forty-seven percent had previously used contraceptives. Ninety-five percent of women and 55% of men said using NFP has helped them to know their body better. Large majorities of men (74%) and women (64%) felt NFP helped to improve their relationship while <10% felt use of NFP had harmed their relationship. Most women (53%) and men (63%) felt using NFP improved their sex life while 32% of women and 24% of men felt it was unchanged from before they used NFP. Seventy-five percent of women and 73% of men said they are either "satisfied" or "very satisfied" with their frequency of sexual intercourse. This survey demonstrates STM of NFP is a well-accepted approach to family planning across several Western cultures. It is consistently viewed as being beneficial to couples' self-knowledge, their relationship, and satisfaction with frequency of sexual intercourse.

Women's interest in natural family planning

Lemaire JC et al., 1998 · J Fam Pract

In the United States, approximately 4% of women of reproductive age use natural family planning (NFP) to avoid pregnancy. It is unclear whether this low number is related to a lack of available information, women's lack of interest, or other factors. Our study examined women's interest in using NFP either to become pregnant or to avoid it. A questionnaire was mailed to 1500 women, aged 18 to 50, who were randomly selected from driver's license renewal records in Missouri for the year beginning July 1991 and ending June 1992. Of the 747 returned questionnaires, 484 were from women who were still potentially fertile. Of these women, 22.5% indicated that they would be likely or very likely to use NFP in the future to avoid pregnancy, and 37.4% indicated that they would be likely or very likely to use NFP in the future to become pregnant. Only 2.8% were currently using a method of NFP. Past use of any method of NFP (including the outdated calendar rhythm method) to avoid pregnancy was associated with interest in future use of modern methods of NFP to avoid pregnancy. Past use of NFP to become pregnant and the possible desire for future pregnancy were associated with interest in future use of NFP to conceive. Many women who are not currently using NFP indicated that they are interested in doing so in the future, either to avoid pregnancy or to conceive. Interest in future use of NFP is associated with, but not limited to, those who have previously used NFP.

Couples' views of the effects of natural family planning on marital dynamics

Vande Vusse L et al., 2003 · J Nurs Scholarsh

Natural Family Planning (NFP) requires periodic abstinence and partner cooperation to prevent pregnancy. The aim of this study was to learn about the effects of modern NFP methods on marital relationships. Descriptive survey. Questionnaires were mailed to 1,400 randomly selected couples known to use NFP and residing in the United States of America; 334 couples (24%) responded. Content analysis was used to identify meanings and themes. Numeric analyses were used to determine frequencies. Findings: Nearly two-thirds of the qualitative comments were positive. Four themes were identified in the positive responses: relationship enhancements, knowledge improvements, spirituality enrichments, and method successes. Three negative themes were identified: strained sexual interactions, worsened relationships, and method problems. Although about one-fourth of the comments indicated that NFP presented challenges, the majority (74%) found it beneficial, often resulting in stronger bonds, better communication, and improved knowledge. NFP had more positive than negative effects and its use warrants further consideration.