Not Your Grandma's Family Planning

Updated October 16, 2023

Doctors, including Ob-Gyn's, spend very little time studying natural methods of family planning (NFP) in medical school. Many of them learn that NFP is 76% effective and move on with life. 86% of the women using NFP for this study used the outdated Calendar-Rhythm method. In 2019, the CDC finally recognized modern Fertility Awareness Methods of NFP are up to 98% effective.

Because of the old information, it's not your doctor's fault if he or she laughs at you and says you'll get pregnant right away (ok, he/she could choose a little more open-minded response). Mostly, doctors are too busy treating patients, filling out paperwork and completing professional development to stay up-to-date on Natural Family Planning Methods. Few physicians are aware that they can study Natural Family Planning Methods for professional development. Lucky for you, there's people like me around whose job is to stay up-to-date on Natural Family Planning.

When I enrolled in the Creighton Model Education Program, I expected to learn about the Creighton Model. To my surprise, we first learned the history of NFP and reproductive anatomy and physiology. Even though I avoided anatomy like the plague through high school and college, I enjoyed learning about the many changes the woman's body goes through each cycle and how the different fertility awareness methods utilize these signs. Without further ado, we will analyze the different natural methods, then compare them to the artificial methods.

What You Need to Know About Fertility

1. A women is fertile for up to 6 days each cycle, regardless of the length of her cycle.
2. Every woman will have short/long cycles during her lifetime.
3. Only 5-12% of cycles are actually 28 days long.
​4. During short cycles, the menses is fertile.
5. 90% of people will achieve pregnancy in 1 year of not using any method.
6. Stress causes a delay in ovulation, causing the women to have a long cycle. Stress can be work/school related, grieving, moving, wedding planning, working out, etc. Not all stressers are bad!
If you want to know the history of fertility awareness, FACTS has a wonderful article!

Important Terms

Natural Family Planning (NFP)-abstaining from intercourse on fertile days to avoid pregnancy or having intercourse on fertile days to achieve pregnancy.
Fertility Awareness Methods-types of NFP that use a women's biological signs to identify fertility. Unfortunately, many types of Fertility Awareness Methods allow contraceptive use on fertile days, therefore Creighton does not consider itself a Fertility Awareness based method.
Fertile Days-days the couple is likely to achieve pregnancy if they engage in intercourse.
Infertile Days-days when the couple can have intercourse if trying to avoid pregnancy.
Pre-ovulatory/Pre-peak-the time before ovulation that includes fertile and infertile days.
Post-ovulatory/Post-peak-the infertile window after ovulation has passed.
Effectiveness
Method Effectiveness-Likelihood of pregnancy in 1 year of perfect use of method.
Use Effectiveness-Likelihood of pregnancy in 1 year of typical use of method.

Short-Cut

If you don't want to read this long and detailed blog, just skip around to the methods that interest you or refer to this quick-reference guide made by Mercy Hospital St. Louis.  There are lots of links in this article, so click the bold underlined words to learn more!

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NFP Methods

The Calendar/Rhythm Method- a.k.a. Your Grandma's Method

Maybe your grandma was even conceived using the Rhythm method since The Rhythm of Sterility and Fertility in Women debuted in 1932. The Rhythm method assumes regular length cycles (28 days) and assumes a fertile window during cycle days 11-17. The modern method of Cycle Beads come from the Rhythm Method and allows for cycles 26-32 days long with fertility indicated on days 8-19. 

The Calendar Rhythm Methods account for the specific women's normal cycles. She records her cycle lengths for 6-12 cycles, then subtracts 19 from her shortest cycle and 10 from her longest cycle to calculate her fertile days for subsequent cycles. Most fertility apps use the Calendar Rhythm Method.

Advantages
No special equipment
Easy to use
Inexpensive (mostly free)
Surprisingly Effective

• Cycle Beads: +95% method effective and 88% use effective
• DOT App: 96-98% method effective.

Disadvantages
Only works during average cycles.
With 12 cycles, 90% of the next 3 will fall within the same length range (Marshall J (1965), Lancet, I 263)
No instructions for postpartum, breastfeeding, or irregular cycles.
Usually more than 9 "fertile" days each cycle.

Popular Methods: all apps and devices that use only your period to determine your fertility.

My take:  Use this method if you aren't serious about planning your family, but want rough estimates of fertility.  Lots of women try to use apps to plan their wedding around their fertile window before they learn an actual method.  This does not work because stress causes cycles to change length!!!

Basal Body Temperature Methods

A women's body produces high amounts of progesterone after ovulation, causing an increase in temperature (yes, you're not imagining it if you feel hotter after ovulation!). Basal Body Temperature (BBT) uses the women's rise in temperature to determine post-ovulatory fertility. BBT uses a special thermometer and must be taken at the same time of day (usually before getting out of bed after waking up). Minor activity should not interfere with BBT, but inadequate sleep, illness and alcohol affect BBT. At least 4 different methods of determining when the temperature has risen enough to count as post-ovulatory exists. New, wearable thermometers take the women's temperature while she sleeps so she does not need to wake up to take her temperature. These thermometers connect to an app which interprets the temperature for her. The most popular of these thermometers is the TempDrop.

Advantages
Inexpensive ($6 for BBT Thermometer, $120 for TempDrop)
Good indicator of post-ovulatory fertility.

Disadvantages
Only determines post-ovulatory fertility (must combine with another method for pre-ovulation fertility).
Time taken, alcohol, inadequate sleep and illness affect BBT unless using a smart thermometer.

Popular Methods:  Must be combined with calendar or sympto-thermal unless you want to avoid until the post-peak phase.

My Take: When Dr. Hilgers, the founder of Creighton, studied Basal Body Temperature, he found the Nadir method of calculating BBT corresponded to ovulation within 2 days 80.3% of the time, Coverline method corresponded to ovulation within 2 days 77.3% of the time, the First Day of Rise corresponded to ovulation within 2 days 65.2% of the time and the Dip corresponded to ovulation within 2 days 12.1% of the time(1). Using Creighton's definition of Peak day corresponded to ovulation within 2 days 95.4% of the time, so Hilgers determined BBT is less helpful than focusing on accurate mucus observations(2).

If we have clients who love their thermometer and aren't ready to give it up when they switch to Creighton, we instruct the husband to monitor the temperature so the wife doesn't allow her temperature to influence her observations. Dr. Hilgers found that women subconsciously convince themselves that an observation is more or less fertile based on her temperature. This can influence accuracy of fertility markings and health indicators. 

1. Hilgers TW and Bailey AG: Natural Family Planning-II. Basal Body Temperature and the Estimated Time of Ovulation. Obstet Gynec 58: 345-350, 1981
2. Hilgers TW, Abraham GE and Cavanagh D: Natural Family Planning-I. The Peak Symptom and the Estimated Time of Ovulation. Obstet. Gynec. 52: 575-582, 1978.

Calendar-Thermal

Calendar-Thermal uses the Calendar-Rhythm method to determine pre-ovulatory fertility and BBT to determine post-ovulatory fertility.

Advantages
High method effectiveness and decent use effectiveness.
Natural Cycles is approved by the FDA and CE for fertility monitoring.

Disadvantages
Does not account for short cycles, postpartum or breastfeeding.
Preovulatory fertility only works with regular cycles.
Must take BBT at the same time each day or invest in a smart thermometer.

Popular Methods: Natural Cycles (UE: 93%, ME:98.2%), LadyComp (UE: unavailable ME: 99.3%) and all apps and calendars that only use your period and temperature are a variation of Calendar-Thermal. I've heard several people recently ask about Ava and Ovusense. Both are designed for conception and do not have appropriate algorithms for trying to avoid pregnancy.

My take: This method is truly as much of a guessing game pre-ovulation as the Calendar-Rhythm method, so choose another method if serious about your family planning choices. No matter how regular you are, each woman will have short or long cycles at some point in her life and this app cannot predict when it will occur.

Sympto-Thermal

Sympto-Thermal combines various symptoms with BBT. The most popular symptoms include mucus and dilation of cervix. Other symptoms include breast tenderness, abdominal pain, abdominal bloating, intermenstrual bleeding and vulvar swelling.

Advantages

Many women feel more confident when cross-checking symptoms.
99.4% Method Effectiveness (scientificamerican.com).
Can not find use effectiveness.
Can be used in all circumstances (breastfeeding, irregular cycles, etc.).
Couple to Couple League has a self-paced class.

Disadvantages

Many women find cross-checking symptoms confusing.
Must take BBT at the same time each day or invest in a smart thermometer.

Popular Methods: Couple-to-Couple League, most NFP books, and SymptoPro.

My Take: Couple-to-Couple League is one of the original NFP methods. SymptoPro is newer, but still has over 35 years of experience. Both have classes in-person or online. Please take an actual class instead of reading a book if deciding to use Sympto-thermal if you want the best results. I am a lover of reading and self-education, but fertility can be finicky and having an expert walk with you is essential. Even as a scientific-minded perfectionist, I learned so much from the conversations with my instructor that you can't get from a book.

Finally, I was intending to use Sympto-thermal, but a friend told me that she switched to Creighton and found it much more straight-forward. Then, Dr. Hilgers explained his research in the various methods and why he kept Creighton as a mucus-only system. I have great respect for Sympto-thermal users and teachers; but, if you're going to check your mucus anyway, why not simplify your life and use a mucus-only system? I may be just slightly biased :)

Mucus-Only

Sperm need mucus to survive, making mucus the hallmark of Fertility Awareness Methods. Everything from Sympto-thermal to the most modern hormone-testing methods recommend that women check their mucus. 

Advantages
Inexpensive (no special equipment).
Used in all circumstances (postpartum, pre-menopause, irregular cycles, etc.).
Can identify medical abnormalities.
High use and method effectiveness.

Disadvantages
Women with no mucus or excessive mucus need additional instructions.
Creighton: 9 meetings in the first year to personalize teaching. Abstinence on the heavy and moderate days of menses and the ~6 days of mucus +3 days post-peak needed to avoid pregnancy after method is learned.
Billings: Can learn from book with optional instructor meetings. Menses, alternative days pre-peak and the ~6 days of mucus +3 days post-peak needed to avoid pregnancy.

Popular Methods: Billings (UE: 97%, ME: 98.6% In China UE: 99.5%, ME: 100%), Creighton (UE: 96.8%, ME: 99.5%) and FEMM (effectiveness not available).

My Take: Billings is the original mucus-only method. Dr. Hilgers developed Creighton from the Billings Method to standardize charting to allow research on medical applications. FEMM is an off-brand of Creighton, complete with medical applications but lacking Dr. Hilgers's methodical, "I won't make any decisions until I see piles of research to back it up" attitude. For example, Dr. Hilgers has been working on developing a charting app for 10 years, FEMM already has one. Some may argue that Dr. Hilgers is so concerned about doing things the right way that he inhibits progress, while Dr. Hilgers says everybody else doesn't take the time to really think things through before implementing changes. These methods are all good, but after meeting Dr. Hilgers, I developed a deep appreciation for his commitment to quality. Billings has better effectiveness, but also fewer days for intercourse. FEMM doesn't have effectiveness studies. For those with a serious reason to avoid pregnancy (i.e. health of the mother), progesterone tests reveal post-ovulatory infertility, which has been used with Creighton with no pregnancies to date. The effectiveness studies (17 years in the making) were published in 2019.

Hormone Test Methods

Advantages
Easy to Use!!!!
Can be used in all circumstances (postpartum, pre-menopause, irregular cycles, etc.).
Use Effectiveness: 89% (98% Marquette monitor-only protocol, 92% Marquette mucus only protocol, 93% Marquette mucus and monitor protocol)
Method Effectiveness: 97.5% (98.4% monitor only with regular cycles, )

Disadvantages
Expensive: Marquette $110 for monitor plus $18-20/month on test strips (more if postpartum).
Mira $199 for monitor plus 10 testing wands and $45 for a box of 20 wands.
Should be combined with Calendar or Mucus method for optimal effectiveness

Popular Methods: Marquette, Boston Cross-Check, Mira and FEMM.

Marquette uses estrogen and LH test strips to determine fertility with optional mucus observations and BBT protocols. My understanding from talking with women is that Marquette uses a calendar algorithm to determine pre-peak days using the monitor-only protocol.

FEMM's free app allows you to track mucus, LH tests, and BBT. Their medical consultants focus on restoring hormonal balance. 

​Boston Cross-Check utilizes at home hormonal monitoring, cervical fluid and temperature tracking. "BCC is an ideal choice for women and couples looking to blend the tried-and-true with the latest technology!"

Mira is a new device that tracks estrogen, LH, FSH and progesterone. It is FDA and CE approved. Designed to help couples achieve pregnancy, it can be used to help couples avoid pregnancy. The hormone levels are 99% accurate, but this doesn't tell us the success rate for avoiding or achieving pregnancy.

 My Take: Women all over the world applaud how EASY Marquette is to use, especially in the postpartum phase. Even though it's "very objective," I would recommend using an instructor. I had three friends in one year who used the test strips (1 the LH and 2 ClearBlue estrogen+LH) and unintentionally achieved pregnancy. Just as I do not want people who "check their mucus" to claim they are using Creighton, I'm not claiming these pregnancies as Marquette "failures." I am saying that you should use an instructor, no matter how straight-forward a method appears.

FEMM's mucus descriptors make me cringe as a Creighton Practitioner. They do not have effectiveness ratings because the method is too new for long-term studies. I think it's really great that their medical professionals focus on balancing women's hormones. FEMM is known for advocating "informed choice," which some instructors include contraceptives in their informed choice instructions.

Just as Marquette discovered adding mucus to their test strip protocol decreased their method effectiveness, Creighton discovered that adding hormone test strips (LH, estrogen+LH and progesterone), decreased the Creighton method effectiveness. As my friend who switched from sympto-thermal to Creighton found mucus-only to be more straight-forward, it appears that focusing on one symptom for any method increases its effectiveness.

Lactational Amenorrhea Method

The hormones your body produces while breastfeeding typically delays ovulation. Ecological Breastfeeding, the gold standard for lacational amenorrhea, claims to prevent ovulation for the one to two years of baby's life. I read on another blog that Ecological Breastfeeding is 98-99% effective for the first six months, but I couldn't find any official report or research study. This article gives the basics of ecological breastfeeding and theorizes how our hormones have changed in the past 40 years, causing a decrease in the effectiveness of ecological breastfeeding.

Advantages
Healthy for mom and baby-I can do an entire post on health benefits
Free
Available (don't have to find a place to heat up formula, etc.)

Disadvantages
Often difficult and painful at first
Not all women CAN breastfeed, especially exclusively
Ecological breastfeeding requires you don't leave your baby for more than a couple of hours (not possible for working moms/day trips, etc.).

My Take: Make your best effort to breastfeed, but don't beat yourself up if you can't. Creighton teaches that exclusive breastfeeding (not necessarily ecological breastfeeding), prevents ovulation for a minimum of 57 days. We also teach that ANY form of supplementation could cause fertility to return at any point. Regardless, we have women track their cycles beginning when the lochia decreases so they are familiar with charting postpartum before fertility returns. For me, it took 15 months for fertility to return even though I started weaning at 6 months. I was still nursing before bed at 15 months, but that's all. 

Non-NFP Methods

All information about contraceptives come from Planned Parenthood because their site is easy to use and correlates with the Center for Disease Control.

Dr. John Billings, founder of the Billings Ovulation Method

Spermicides

Spermicides block the cervix and stop sperm motility.

Advantages
Inexpensive~$0.60 per use (or free)
Hormone-free

Disadvantages
Ineffective (82% Method Effective)
High incorrect usage rate (72% Use Effective)
Messy
May cause irritation

Popular Methods: Phexxi-kills sperm by keeping the pH of the vagina low.

My Take: Spermicides are ineffective, but are often recommended to use with barrier methods. Many lubricants contain spermicides, so if you would like lubrication without the spermicidal effect, check the box for non-spermicidal versions or use kitchen oils (I've heard many success stories with vegetable or coconut oils).

Withdrawal

Withdrawal works by the man pulling out before ejaculation.

Advantages
Free
​Hormone-free
No Side Effects
​96% Method Effective

Disadvantages
Requires male awareness and self-control.
Pre-ejaculate fluid contains sperm.
Interrupts the sexual act at the height of pleasure.
​78% Use Effective

My Take: Many wonder why Withdrawal isn't considered part of NFP. It is not natural to interrupt intercourse at the height of pleasure! This takes away from the bonding experience for both the man and the woman, which is one of the two moral reasons to choose NFP.

Theologically, each act of intercourse represents a renewal of the marriage vows. With the use of NFP, we invite God to create a child with each act of intercourse, even when we know He scientifically cannot during a particular act of intercourse. With Withdrawal and other forms of contraception, we no longer invite God to the renewal of our marriage vows. It's like sending Him an "uninvite." 

Barrier Methods

Barrier Methods are not a form of NFP. They work by blocking the sperm from entering the cervix. 

Advantages
Easily accessible (no prescription)
​Decent Method Effectiveness 
Can protect against IUDs and IUIs.

Disadvantages
High incorrect usage rate 
Must "suit up" for intercourse

Popular Methods: Condom (UE: 85%, ME: 98%), Diaphragm (UE: 88%, ME: 94%), and Cervical Cap (86% effective if never given birth, 71% effective if you've given birth).

My Take: I once read a blog saying condoms were the answer to abortion. I discovered that 50% of those who get an abortion do so because of failure of contraceptive method. Barrier methods have the highest difference between correct use effectiveness and incorrect use effectiveness of any method, so I would argue that they contribute more to abortions than protect from abortions.

Hormone Methods

The progestin in hormonal birth controls is an artificial version of progesterone that prevents implantation, limits mucus production, interferes with ovum transport and reduces ovulation. 

Advantages
High Effectiveness
Most are impossible to use incorrectly
Most recommended form of birth control by gynecologist
Helps with unusual bleeding, PMS and other health problems

Disadvantages
Increased risk of breast cancer and stroke
Side Effects include nausea, weight gain,  headaches and cysts.
Covers up symptoms of underlying problems.

Popular Methods: Birth Control Pill (UE: 93%, ME: >99%), Birth Control Patch (UE: 93%, ME: 99%), Hormonal IUDs (UE: 99.9%, ME: 99.9%), Depo Provera (UE: 96%, ME: 99%), Vaginal Ring (UE: 93%, ME: 99%) and Arm Inserts (UE: 99%, ME: 99%). Each of these have increased 1-3% in use effectiveness since I updated the website in 2021.

My Take: Although the amount of estrogen in hormonal birth control is much lower than it to be, a 10+ year study of 1.8 million Danish women found that hormonal birth control users experience a 20% increased likelihood for breast cancer compared to non-users. For those on birth control for 10 or more years, the likelihood increased to 38% above non-users. Even those who used the hormones for five or less years had an increased likelihood for breast cancer that continued after they discontinued using the birth control. When interviewed by the New York Times about the study, Dr. Weiss said "It's not like you don't have a choice, why not pursue another option?"

IUDs

Non-hormonal IUDs work as a spermicide and by preventing implantation. Hormonal IUDs first work like any other hormonal contraceptive, but have the implantation preventing mechanism as a back-up.

Advantages
Long-lasting (3-12 years)
VERY effective (99.9% method and use effectiveness)
Easy to use, just check the string to make sure it's still in

Disadvantages
Prevents a developing zygote from implanting
If pregnancy occurs, likely to be ectopic
Can fall out
​Can perforate uterus

Popular Methods: ParaGuard (copper, non-hormonal, lasts 12 years), Mirena (hormonal, 7 years), Kyleena (hormonal, 5 years), Liletta (hormonal, 7 years), Skyla (hormonal, 3 years).

My Take: If you believe life begins at conception, the prevention of a developing zygote from implanting is very concerning. If that doesn't bother you, if you don't believe intercourse needs to be both procreative and unitive, and if you want a long-last contraceptive, ParaGuard is hormone-free with low risk of side effects (though uterus perforation and ectopic pregnancy are quite serious when they occur).

Permanent Solutions

Vasectomy and Tubal Ligation provide permanent pregnancy prevention. Vasectomy cuts the Vas Deferens, so the sperm don't make it into the seminal fluid. Tubal Ligation clamps, blocks or seals the Fallopian Tubes so the egg can't pass to be fertilized. These are both permanent, yet reversible surgical procedures. A new type of non-surgical tubal blockage called FemBloc is currently under clinical trial.

Advantages
Permanent
Effective (nearly 100% effective after 3 months).

Disadvantages
Must wait 3 months to be effective
Risks of surgery complications
Tubal Ligation reverse success is 40-85% and has increased ectopic pregnancy rates.
Vasectomy reverse success is 40-75%.

My Take: These methods are permanent. Many tubal ligations are performed postpartum, meaning within hours or a couple of days after birth while the uterus is still enlarged. If you have ever given birth, you know that pregnancy and postpartum are not the right time to make permanent contraceptive decisions as many women think "I never want to go through THAT again" for several days or months or years before wanting another baby.

Final Thoughts

Whew, I finally made it to the end of this blog. I love educating people on reproductive health, but taking a couple of weeks to compile this information is draining! If I have a typo or missed a type of birth control or a reference link, please let me know as my brain is pretty fried right now. I hope you join me next week for the more anecdotal/less scientific blog NFP is Hard.