The Boston Cross Check (BCC) is a thorough, cautious fertility awareness method that can be approached in two ways:
- Monitor: Using a hand-held device to measure key hormones that determine a woman’s fertile window.
- Sympto-Thermal: Observing a woman’s own biological signs (or biomarkers) to identify their fertile window.
This method has its early roots in the symptothermal approach. The New England Natural Family Planning Association developed standards for monitoring fertility and taught them at Boston hospitals in the 1970’s.
This ended in 1993 when client education programs became parish-based through the Boston Catholic Archdiocese. At-home hormonal monitoring was introduced years later in 2005, and only for women with regular cycles. It wasn’t until 2013 that it was extended to include postpartum women.
Remote online instruction was pioneered in 2011, and in 2019 the method was transferred entirely into the hands of a Board of instructors. Under this group, BCC has acquired approval from the United States Conference of Catholic Bishops for use in Catholic parishes throughout America, but it is open to users of all faiths throughout the world.
Biomarkers Tracked
Boston Cross Check recommends a cross-check approach, which means a combination of two or more biomarkers. However, there is a way to rely on a single biomarker when required.
1. Hormone Levels: A Clearblue Fertility Monitor is used to identify the levels of two key hormones - Estrogen and the Luteinizing Hormone (LH). LH tests (collected from a woman’s urine) are required for postpartum women, but optional otherwise.
2. Temperature: A Basal Body Temperature (BBT) thermometer will be used to measure the temperature of a woman’s body when she is completely at rest. This could also be done with a Tempdrop device.
3. Cervical Fluid: Mucus from a woman’s cervix changes throughout her menstrual cycle and can be measured from home. Wet and slippery cervical mucus would be an indication of fertility.
Optional biomarkers include:
1. Hormone Levels: The company Proov has developed the “Proov Confirm PdG” test. This test is a urine marker of the hormone progesterone (PdG) and is another excellent indicator for the fertility cycle.
2. Cervical Position: Women can self-test to determine the position of their cervix. A cervix that is high, soft, and open is fertile. A cervix that is low, firm, and closed is infertile.
How the Boston Cross Check Method Works
The Boston Cross Check method uses a combination of biomarkers for real-time fertility status, alongside well-established “double-check” or algorithmic/calculation rules to help open the fertile window.
A woman’s fertile window is closed if her biomarkers indicate infertility. Boston Cross Check adopts a cautious approach to ensure maximum effectiveness in avoiding pregnancy but can also be used to pursue pregnancy or simply to help monitor female health.
How a woman tracks her cycle will depend on which tools she chooses to use. For example, according to the BCC rules, Basal Body Temperature (BBT) from the night before should be noted every morning. If she chose to include hormone tests, she would typically test early in the day and know the results within minutes. If she chose to also include cervical fluid, the sensation and visual characteristics should be observed throughout the day, and then the most fertile observation will be recorded at the end of the day.
Here’s a typical daily observation plan for someone using BCC, with the most popular combination of monitor and temps:
- BBT: Observed daily each morning and charted at any time that day.*
- Hormonal Tests: Performed daily (often in the morning) and charted at any time that day.
A woman may also choose to add in biomarkers:
- Cervical Mucus: Observed periodically throughout the day and charted at the end of the day.
-
Cervix position: Observed and charted once at the end of the day.
An example of a Tempdrop chart showing daily BBT readings, ovulation, thew fertile window and cervical mucus observations.
*Note that BCC only recommends digital BBT thermometers (like Tempdrop) that hold the results in their memory to ensure the best experience for a user of the method. This way, it is not necessary to record the BBT reading right away. Instead, it can be retrieved at a more convenient time.
Benefits of the Boston Cross Check Method
High Efficacy: Boston Cross Check does not have method-specific research studies published. However, the method is based on well-studied rules, with established effectiveness. Depending on the circumstances of charting (regular cycles, postpartum cycles, perimenopause) and which biomarkers are chosen, the effectiveness of the Boston Cross Check method, for avoiding pregnancy, is expected to be between 98-100% with correct use. BCC leans to a more conservative side, which is appreciated by women who have experienced fertility tracking failures in the past. Instructors are trained to tailor the method to match a woman’s comfort levels for anticipated effectiveness vs. ease of use/cost factors.
Multiple Uses: For achieving pregnancy, it is expected that ~90% of BCC users will become pregnant within 6 cycles of trying, and they are referred for a medical evaluation if this does not occur.
Flexibility: With its range of biomarker options, the Boston Cross Check Method is highly flexible. It can often be customized for success through the varied phases of a woman’s reproductive life.
Disadvantages of the Boston Cross Check Method
High Demand: As a smaller method that runs only one instructor training course per year, the demand for instructors can sometimes outstrip supply.
Limited Additional Materials: BCC does not currently incorporate quantitative hormonal monitors (aside from PdG and LH tests that provide quantitative results) into their materials. Some women opt to use them alongside Boston Cross Check, but we are unable to support their stand-alone use within the method.
Cost: There are higher financial costs incurred with the Boston Cross Check method due to ongoing monitor use. Instructors can minimize the cost of hormonal testing for their clients when needed. This would require an adjustment to the testing approach, but there will still be a cost associated with using any hormonal tests.
Considerations & Support
As with all fertility awareness methods, BBC has a learning curve. It is traditionally considered to be around three months.
Boston Cross Check is taught by certified educators. Our Method Instructional Program for regular cycles consists of 4 live, personalized teaching sessions spaced over the first year of use, with the steepest learning curve only applying to the first couple of sessions. Most clients feel confident in using BCC after completing 3 cycles of charting. However, the program offers a full year of unlimited consultations in addition to the four teaching sessions.
There are additional programs available for women with special circumstances. For example, the Post-partum Service and the Perimenopause Service.
- Postpartum Service: Runs from the time charting begins after your baby’s birth until 6 cycles have been completed after the menstrual cycle returns.
- Perimenopause Service: Runs for one year. Once a client’s service is complete, if they would like ongoing support, they can keep their instructor “on retainer” for unlimited consultations at $75 per year. If they feel confident to continue alone, they may reach out for any needed guidance for a $25 one-off consult.
Neurodivergence consideration: Sometimes clients with certain forms of neurodivergence can struggle with the consistency of regular charting that all fertility tracking methods require. For those who struggle with consistency, there are two main approaches an instructor may suggest: either to focus closely on a single biomarker and relax more with the others or to incorporate as many biomarkers as possible and try to “piece together” the chart.
Boston Cross Check’s use of hormonal tests and support for Tempdrop use both fit well with delegating aspects of the routine to a partner. A partner can ensure a woman is wearing her Tempdrop each night and remind her to provide a sample for hormonal testing each morning. The partner can do the testing, record the results of hormone tests and temperatures, and also help interpret the chart.
BCC includes instruction on how to approach biomarkers through travel, shift work, and other special circumstances.
Who is the Boston Cross Check Method best for:
This method works best for women who would prefer to rely on more than one biomarker. For women trying to avoid pregnancy, Boston Cross Check works best for those who are willing to refrain from sexual intercourse during the fertile phase (since effectiveness is likely to be lower for those who do not refrain).
BCC is a great option for women with regular cycles, especially those preparing for marriage, who want to learn how to track their cycles and understand their body’s key signs before adapting the method to fit their lifestyle.
The method is also popular for postpartum and breastfeeding use, especially with the inclusion of at-home hormonal monitoring.
For women with very long or irregular cycles, and who do not wish to use a mucus-only symptothermal method such as Billings or Creighton, we offer modified protocols that increase the flexibility of the approach and reduce abstinence. The only catch is that these protocols do not always have established efficacy figures behind them.
Where to Learn More
- Official website
- Official Instagram page
- Boston Cross Check Facebook group
- Monitor Methods support group
Boston Cross Check in a Nutshell
- Biomarkers Tracked: Hormone tests (Clearblue monitor, LH tests, Proof Confirm PdG tests), Basal body temperature (Tempdrop wearable or oral BBT thermometer), cervical fluid, cervix position
- Effectiveness: Very high. Estimated to fall between 98-100% for correct use - 98% (at lowest for monitor-only postpartum/breastfeeding) to ~ 99.8% with a progesterone-based cross-check in regular cycles. Typical use might be estimated to be in the low to mid 90s%.
- Learning Curve: Most women feel confident after 3 cycles of charting.
- Ideal For: Anybody who likes a multi-pronged approach to charting.
-
Where to Learn More: You can check our official pages listed above or the websites of some of our Board Members:
Meet Someone That Knows The Method - Mikayla Dalton
Mikayla has been teaching Boston Cross Check online since 2011. She feels
privileged to have accompanied hundreds of women and couples through so many different fertility experiences. Mikayla has been married for 15 years and has 3 children, plus the occasional international exchange student. A FemTech geek, her husband once told Mikayla that she looked like the Borg queen with all her fertility wearables on. Resistance, she told him, is futile.
More websites and contact information for other instructors can be found on our Instagram page.