Natural Family Planning for beginners, the 4 methods compared (Creighton, Billings, Sympto-Thermal, Marquette)

The four main NFP methods differ in the fertility signs they read. Creighton and Billings track cervical mucus, Sympto-Thermal adds waking temperature, and Marquette uses a hormone monitor. All four are morally acceptable and best learned with a certified instructor.

That's the short version. The longer version matters, because choosing a method is a practical decision that depends on your cycles, your sleep, your season of life and frankly your temperament. Below we explain what NFP is, what the Church teaches about it, how each of the four methods works, and how to decide between them. This guide is written for beginners, so we'll keep the language plain. It is not medical advice, and anything unusual about your cycle or health is a question for a doctor.

What natural family planning is (and isn't)

Natural Family Planning is the general name for scientific, natural methods that help married couples either achieve or postpone pregnancy by observing the signs of the fertile and infertile phases of a woman's cycle, with no drugs, devices or surgery (USCCB, What is Natural Family Planning?).

The basic biology is simple. A man is fertile throughout his adult life, while a woman is fertile for only a few days in each cycle during her childbearing years (USCCB, Married Love and the Gift of Life). NFP teaches a couple to recognize those days. If they have a serious reason to avoid pregnancy, they abstain from intercourse during the fertile time. If they hope to conceive, the same knowledge helps them time intimacy.

Two misunderstandings are worth clearing up early.

• NFP is not the calendar rhythm method. Modern methods don't predict fertility from past cycle lengths. They read signs the body gives in the current cycle.
• NFP is not guesswork. The methods come from research on the cyclic changes in cervical mucus and the rise in temperature after ovulation, and that research continues (USCCB, Is NFP based on guesswork?).

You also don't need perfectly regular cycles. The methods can be adapted to irregular cycles, breastfeeding and the years approaching menopause, ideally with a trained instructor's help (USCCB, Who can use NFP?). Our Natural Family Planning page gives a fuller introduction if you're starting from zero.

What the Church teaches about NFP

It helps to separate Church doctrine from practical advice, because people sometimes mix them up.

The doctrine

The Church teaches that spouses may, for just reasons, wish to space the births of their children, and that they should make sure this desire comes from the generosity of responsible parenthood and not from selfishness (CCC 2368). Pope Paul VI wrote that when there are well-grounded reasons for spacing births, arising from the physical or psychological condition of the spouses or from external circumstances, married couples may make use of the natural cycles and have intercourse only during infertile times (Humanae Vitae 16).

The Catechism explains why this differs from contraception. Methods based on self-observation and the use of infertile periods "respect the bodies of the spouses, encourage tenderness between them, and favor the education of an authentic freedom," while any action intended to make procreation impossible is excluded (CCC 2370). The U.S. bishops put the difference simply. The end result may look similar, but the way a couple gets there makes a real moral difference (USCCB, Married Love and the Gift of Life).

What the Church does not decide for you

The Church doesn't endorse one method over another. Creighton, Billings, Sympto-Thermal and Marquette are all morally equivalent, because they all work the same way at the level that matters morally: they read the body's signs and the couple chooses when to come together. Which method you use is a practical choice. Pope Francis also reminds couples that family planning should come from "consensual dialogue" between the spouses, with respect for each other's dignity (Amoris Laetitia 222). In other words, it's a decision you make together.

If you'd like the theology behind all this, our simple explanation of the Theology of the Body shows why the Church cares so much about the meaning of the body.

The four methods compared

Creighton Model

What it reads. Cervical mucus, observed in a standardized way. The woman notes what she sees and feels at the vulva through the day and records it with a precise vocabulary and a standardized chart.

What sets it apart. The charting is very structured, and that consistency is deliberate. A standardized chart can be read by trained medical consultants, which connects Creighton to NaProTechnology, a medical approach that uses the chart to look for underlying causes of problems such as irregular bleeding, painful cycles, recurrent miscarriage or difficulty conceiving.

Who it tends to suit. Couples who like clear rules and detail, women with cycle-related health concerns who want a doctor to evaluate their charts, and couples facing infertility. It also has guidance for breastfeeding and irregular cycles.

How it's taught. Usually through an introductory session followed by a series of individual follow-up meetings with a certified practitioner over many months.

Billings Ovulation Method

What it reads. Cervical mucus, with particular emphasis on the sensation the woman notices at the vulva during ordinary daily activity.

What sets it apart. Simplicity. Billings uses a small set of rules and relies on the woman learning her own pattern rather than on a fixed vocabulary for every observation. No thermometer or device is needed.

Who it tends to suit. Couples who want a low-tech, low-cost method, women with irregular cycles, breastfeeding mothers, and couples whose sleep is unpredictable, since nothing depends on a morning temperature.

How it's taught. By accredited teachers, usually in a few sessions with follow-up while you chart your first cycles.

Sympto-Thermal Method

What it reads. More than one sign. Most Sympto-Thermal approaches combine cervical mucus with basal body temperature (the waking temperature, which rises after ovulation), and some also include changes in the cervix itself as an optional sign.

What sets it apart. Cross-checking. Mucus tells you when fertility is approaching, and the temperature rise confirms that ovulation has passed. Many couples find that having two signs agree gives them confidence.

Who it tends to suit. Couples who like to see confirmation, people who are comfortable with numbers and charts, and women with fairly regular sleep. Temperature is less reliable with shift work, broken nights with a baby, illness, travel or alcohol, so some couples lean more on mucus during those seasons.

How it's taught. In classes or by a couple of instructors, often over a short series of sessions, sometimes as couple to couple teaching.

Marquette Model

What it reads. Hormones. A home fertility monitor measures hormone levels in urine (an estrogen-related hormone that rises before ovulation and the hormone surge that triggers it). Many couples add mucus or temperature as optional extra signs.

What sets it apart. An objective reading. Instead of interpreting a sensation or a pattern, you read a result from the monitor. Marquette also has specific protocols for breastfeeding, coming off hormonal contraception and the years approaching menopause.

Who it tends to suit. Women who find mucus hard to interpret, breastfeeding mothers, women with irregular cycles or in perimenopause, and couples who like data. There's an ongoing cost for test strips, which some couples find a drawback.

How it's taught. By trained instructors, often nurses or other health professionals, frequently online with regular chart reviews.

How to choose a method

There's no single best method, only the best fit for your situation right now. A few questions help.

1. Are you breastfeeding? Mucus-based methods and Marquette all have postpartum guidance. Temperature is harder to use with broken sleep. Our page on intimacy after birth covers this season more broadly.
2. Do you work nights or have irregular sleep? Lean toward a mucus method or Marquette rather than relying on temperature.
3. Are your cycles irregular, or is something medically off? See a doctor first. Creighton with NaProTechnology is designed for couples who want the chart to support a medical evaluation, and Marquette's monitor helps when signs are confusing.
4. How do you each prefer to work? Some people want structure and detail, others want as few rules as possible. That preference is a real factor.
5. What's your budget and access? Billings and Sympto-Thermal need little equipment. Marquette needs a monitor and strips. Check what instructors are available to you in person or online.

Some couples switch methods across the years, for example using Marquette after a baby and returning to a mucus method later. That's fine. What matters is that you learn whichever method you use properly.

Why an instructor makes the difference

Every method relies on correct observation and correct application of its rules, and that's very hard to learn from a book or an app alone. A certified instructor reviews your charts, catches mistakes early and helps in tricky seasons such as postpartum, stress or illness. Most methods ask you to chart for a few cycles with your instructor before you rely on the method to postpone pregnancy.

Learning together also matters. NFP is a shared practice, not something the wife handles alone. When husbands chart alongside their wives, ask questions and share the decisions about when to come together, couples often find that it changes how they talk about intimacy in general. The Catechism's point that these methods "encourage tenderness" is something many couples recognize in practice (CCC 2370).

The periods of abstinence can be hard, and the Church doesn't pretend otherwise. The Council acknowledged that couples who must avoid increasing their family for a time can find fidelity and love harder to sustain (Gaudium et Spes 51). It helps to plan other ways of being close during those days and to talk honestly about how you're each doing.

Where to go from here

If you're engaged, it's worth starting to chart before the wedding so the method is familiar by the time you're married. Our marriage preparation resources include NFP basics, and the Engaged program covers it in more depth.

On CatholicSex.com, the library and courses include an NFP and fertility track, Ask with Sources answers questions with citations to Church documents, and the monthly live Q&A regularly includes NFP questions. Through the Couples Program you can also book a private 30 minute video consultation with an NFP instructor every 3 months, which can help when you're deciding between methods or troubleshooting your charts. You can see what's included on the pricing page. For the bigger picture of how all of this fits into married life, start with our guide to Catholic intimacy.

Frequently asked questions

Which NFP method is the most effective?

Each of the four methods can be very effective when it's learned from a certified instructor and its rules are followed. How well a method works for you depends heavily on correct learning and consistent use, so choose the one you can realistically practice and get proper instruction.

Can I use NFP with irregular cycles?

Yes. Modern methods read the signs of the current cycle, so regular cycles aren't required. Irregular cycles can have medical causes, though, so it's wise to see a doctor as well. Creighton with NaProTechnology and Marquette are often chosen in this situation.

Is using NFP the same as using contraception?

No. The Church teaches that using the natural infertile times for just reasons respects the meaning of the marital act, while contraception deliberately makes the act infertile. The result may look similar, but the way couples act is morally different.

Do we need a serious reason to use NFP to avoid pregnancy?

The Church speaks of just or well-grounded reasons, which can be physical, psychological or external circumstances. Couples discern this together in prayer, with generosity. Using NFP to understand your fertility or to conceive needs no special reason at all.