Human sexuality is woven into the fabric of each man and woman. It carries within it the powers of love and life and is the human source of our most basic relationships as members of a family (see Love and Sexuality).
Striving to understand God's design of human fertility, reveals the marvelous intention of the Creator--to unite the two into one flesh where new life may worthily enter the world.
The methods of Natural Family Planning (NFP) exist because of God's design of man, woman, human sexuality and fertility. NFP methodology is based on scientific research about women's menstrual cycles, the signs of female fertility which are related to the event of ovulation (when a mature egg is released from an ovary in the woman's body), and the "fertile window" which takes into account how long a man's sperm can live in a woman's body.
Over a century ago, scientists discovered cyclic changes in a woman's cervical fluid (or "mucus") and their relation to ovulation. In the 1920s, scientists identified the temperature rise ("basal body temperature" or BBT) that signals ovulation. But it wasn't until the 1950s that scientists developed programs to teach others how to observe and interpret these fertility signs. Today, ongoing research continues to refine the methods of NFP. Here we present both classic and current NFP research.
NFP Science Resources
NFP Science Meetings
At their annual conference, the Catholic Medical Association (CMA) holds an NFP pre-conference meeting. Typically these meetings cover current NFP scientific research. Videos from the meeting can be purchased on the CMA website. CMEs are also available per meeting. See the CMA website for more information.
2024 International NFP Scientists' Meeting
At this meeting, NFP scientists from Canada, Chile, France, Germany, Italy, and the United States gathered to:
Identify the gaps in research evidence for effective evidenced-based methods of natural family planning (NFP) for women with all reproductive categories.Determine the gaps in the research and development of new technology for providing NFP services.
Determine the gaps in the research literature that demonstrate the benefits and challenges with use of NFP among married couples.
And, to provide prioritized ideas for future research or needs for research from the analysis of evidence gaps from the above objectives.
Diocesan NFP leaders (directors, coordinators, teachers, and promoters) can qualify for a 50% discount on the cost of the set of talks. Please discount code IGHSD when on the website.- 2023 NFP Science Forum
Topics include: Evaluating Pregnancy Rates in Fertility Awareness Based Methods; Educating Medical and Health Professional Students on FABMs via an Online Elective; Perimenopause and Fertility Tracking; Quantitative At-Home Hormone Monitoring for Finding Fertile Days, Confirming Ovulation, and Screening for Ovulatory Dysfunction; A Case Series: Using the Mira Monitor During the Postpartum Breastfeeding Transition; A Case Series Study of Women Diagnosed with Polycystic Ovary Syndrome (PCOS) Who Used Hormonal Monitoring to Avoid Pregnancy.
- 2022 NFP Science Forum
Topics include: Effects of COVID-19 Vaccines on the Parameters of the Menstrual Cycle; Descriptive Analysis of Hormonal Patterns During the Postpartum Transition to Fertility; Effectiveness of a Protocol for Avoiding Pregnancy During the Postpartum Transition to Fertility; Does a Short Luteal Phase Correlate with an Increased Risk of Miscarriage?; A Comparison of Contraceptive and NFP Use on the Odds of Divorce and Separation as Found in the 2017-2019 NSFG.
- 2021 NFP Forum--Virtual Meeting
Topics include: What’s new with NFP; clinical evidence, new technologies, and the patient/physician interaction; Effectiveness of FABMs in Special Populations; Validating a Quantitative Urine Hormone Monitor for Use in Natural Family Planning; OOVA: The Next Generation of Urine Hormone Testing;
Application of the PREMOM Fertility Monitoring System for Natural Family Planning.
- 2019 NFP Forum
Topics include: Effectiveness of Fertility Awareness-Based Methods for Avoiding Pregnancy: A Systematic Review; The Dot Fertility App: An Effective Approach to Expanding Access to Fertility Awareness-Based Method; The Real-World Application of the Marquette Model Natural Family Planning Method (MM-NFP): A Multi-Site Effectiveness Study; Use of Urine Progesterone Tests for More Accurate Ovulation Monitoring; Patients’ Experience in Conversing with Clinicians About Fertility Awareness Based Methods.
- 2018 NFP Forum
Topics include: Evidence for Effectiveness of NFP Methods to Postpone Pregnancy; Evidence for Effectiveness in Transition Periods (Postpartum/ Breastfeeding/Perimenopause); Impact of NFP on Marital Dynamics.
- 2017 NFP Forum--Focus on the Creighton Model FertilityCare System
Topics include: The Professional Infrastructure of the Creighton Model System; Growth of Education Programs with Accreditation; The Biomarkers of the Creighton Model System; Advanced Hormonal Support with the Creighton Model System; The Impact of Introducing NaproTechnology into the Private Practice of Obstetrics & Gynecology; Surgery for Treating Polycystic Ovaries; Surgery for Treating Endometriosis; Adhesion Prevention Measures.
Current Medical Research
This biannual publication provides reviews of research on the methods of NFP and related topics.
Please note, this publication is temporarily suspended while we search for a new editor.
Fertility Health
Many people do not have an adequate understanding about God's gift of human fertility. And, many people do not know about how to maintain fertility health. In this video Mary Lee Barron, PhD, RN, APRN, FNP-BC, FAANP, discusses this important topic. Recorded as part of the USCCB's NFP Programs "NFP Office Hours," this webinar includes discussion with the participants who are diocesan NFP teachers and coordinators.
of this presentation. Visit the Fertility Health page at Dr. Barron's website, Marquette Fertility Education.
NFP Education for Healthcare Professionals
NFP Science Bibliography
This bibliography provides a listing of classic and current NFP research.
NFP Science PowerPoint Presentations
NFP Fact Checker
This one-hour and fifteen-minute audio file is from the 2013 annual conference of the National Association of Catholic Family Life Directors (NACFLM). The panel discusses the research behind such topics as NFP effectiveness rates, the truth (or myth) behind the "less than 5% divorce rate" of NFP users; and other commonly misunderstood "facts" about NFP. Although produced in 2013, the content highlights principles that guide evidence-based review of NFP research.
Panelists are Richard Fehring, Ph.D., RN, NFP Institute, Marquette University, College of Nursing, and Michael Manhart, Ph.D., Couple to Couple League. The MC is Theresa Notare, Ph.D., Assistant Director, NFP Program, Secretariat of Laity, Marriage, Family Life, and Youth, USCCB.
Part One | Part Two | Part Three | Part Four | Part Five
NFP Fact Checker PowerPoint Slides
Part I | Part II Please view Dr. Fehring and Dr. Manhart's slides that accompany the talks.
Select NFP Science Articles
(See also the NFP Science Bibliography for a list of foundational and current research.)
The content below represents the research of the authors. Links to external websites are provided solely for the user's convenience. Reference to these sites does not imply USCCB official endorsement.
Please be patient with us as we continue to develop this page. Send suggestions to nfp@usccb.org.
General NFP Science
- "Natural Family Planning: A Review," Hanna Klaus, MD.
This article provides a review of the foundational scientific research behind the various methods of NFP.