Natural family planning is not “one thing.”
NFP methods differ in a couple important ways:
- which fertile signs are tracked,
- how they are tracked, and
- how fertile and infertile observations are used to identify the fertile window (that is, the “rules” the method uses to determine whether or not a woman is potentially fertile in any given day.)
There are perhaps a surprising number of ways woman can track their fertility, and there is no one “best” method for all women, all the time. Many women, in fact, use different methods at different times in their life, as their circumstances change. Choosing which method of NFP will be the best fit for you is a personal and practical choice.
I’m a Marquette Method instructor, which is a method which is based in measuring hormone levels (estrogen and LH, specifically) via urine tests.
Women using the Marquette Method also have the option to include other fertile signs into the observation routine, such as basal body temperature (BBT) readings, cervical mucus observations, and urinary progesterone tests. (For a full explanation of the Marquette Method protocol options, consult my Marquette Method Guide.)
The chart below outlines some of the major similarities and differences between different methods of NFP, according to the fertile signs that the method tracks.
Billings Ovulation Method
Couple to Couple League (Symptothermal)
Single-Check vs. Double-Check or Cross-Check Methods of NFP
Other methods, sometimes called double-check or cross-check methods of NFP, track multiple signs concurrently. Symptothermal methods include the Couple to Couple League, Serena, Sensiplan, and SymptoPro.
The Marquette Method is somewhat unique in that it relies on testing and tracking hormone levels directly, through at-home urine tests which measure estrogen and LH levels, but Marquette Method users can also opt to include a variety of optional signs into their testing routine, including urinary progesterone tests, basal body temperatures, and cervical mucus observations.
Which Methods of NFP Track Which Fertile Signs?
Estrogen Levels (Urinary Hormones) | Marquette Method Only
The Marquette Method of NFP is the only method that uses urinary estrogen levels as a primary indicator of fertility. Clearblue Fertility Monitor Test Sticks measure estrogen and LH levels concurrently, and these results are interpreted by the Clearblue Fertility monitor.
Currently, Clearblue monitors are the only fertility monitors on the market which test urinary estrogen levels. The Mira Fertility Plus system, not yet available, will also track estrogen levels, and preliminary studies are underway to compare the ease of use, user satisfaction, and accuracy of the Mira system vs. the Clearblue system.
Luteinizing Hormone (LH) Levels (Urinary Hormones) | Marquette Method, FEMM (Optional)
At the end of the pre-ovulatory phase of the menstrual cycle, woman experience a surge in luteinizing hormone (LH) levels. This “LH surge” precedes ovulation by 24-36 hours. The LH surge causes the follicle to break open and release a mature egg.
Unlike changes in estrogen levels, which change a woman’s cervical mucus secretions, LH is asymptomatic, but it can be measured in urine. Clearblue Fertility Monitor Test sticks, used by the Marquette Method, test both estrogen and LH levels.
LH levels can also be measued by single-use LH test sticks, such as the Wondfo brand of LH test sticks. The FEMM method of natural family planning uses LH test sticks, rather than Clearblue monitors, to track LH levels.
Progesterone Levels (Urinary Hormones) | Marquette Method (Optional), FEMM (Optional)
In the post-ovulatory phase of the menstrual cycle, the empty follicle breaks down and secretes progesterone.
Cervical Mucus | Creighton Model, Billings Ovulation Method, Symptothermal Methods, FEMM, Marquette Method (Optional)
Tracking cervical mucus secretions has long been a primary means of identifying the fertile window. The consistency of a woman’s cervical mucus changes as her menstrual cycle progresses.
As estrogen levels rise in the pre-ovulatory phase of the menstrual cycle, cervical mucus becomes more abundant, stretchy, and slippery. This peak-type mucus is sometimes called EWCM mucus (egg white cervical mucus) because it’s consistency resembles egg whites. In the post-ovulatory phase, mucus “dries up” or becomes less abundant, stretchy or slippery.
Methods that include cervical mucus obervations teach women how to observe and classify their cervical mucus daily and record these observations on their NFP chart.
One thing that differentiates the Marquette method from other modern methods of NFP is that Marquette tracking cervical mucus is an optional sign, because estrogen levels are measured directly (though urinary estrogen metabolites) rather than symptomatically (through cervical mucus consistency.)
Basal Body Temperatures (BBT) | Symptothermal Methods, Marquette Method (Optional)
Rising progesterone levels in the post-ovulatory phase of the menstrual cycle cause a woman’s body temperature to increase by 0.4-0.6 degrees Farhenheit.
Symptothermal methods of NFP track this temperature shift by having woman take their basal body temperature (BBT) upon waking each day, and then recording their daily temperature on their fertility chart. Women can take their temperature using a digital oral thermometer or a “smart,” wearable thermometer like the TempDrop.
The Marquette Method has optional protocols for including BBT readings into a woman’s Marquette Method routine.
Cervical Position | Some Symptothermal Methods (Optional)
In the lead up to ovulation, a woman’s cervix rises and becomes softer. At the height of ovulation, the uterine os opens to allow sperm to pass through. In the post-ovulatory period, a woman’s cervix lowers, closes, and becomes more firm.
Some symptothermal methods of NFP include internal cervical checks as a secondary, optional fertile sign.