If you’re looking to use a monitor-based Natural Family Planning method, you might be trying to figure out what your various options are, and how they are different. This blog post compares two current methods which utilize the Clearblue fertility monitor: the Marquette Model and Boston Cross Check.
As a Boston Cross Check instructor, I often get asked about what the differences are between the Marquette Model of NFP and our method. A lot of people assume that BCC is simply “Marquette + BBT,” meaning that Boston Cross Check has taken Marquette protocols and added a basal body temperature sign, but this actually misrepresents both methods! What I hope to do here is to give you a sense of how these methods are similar, and how they might be different from the user perspective. Unless otherwise stated, protocol references I will make refer to standard protocols in the case of each method, meaning that the woman or couple are in a “regular” cycling situation as distinct from particular medical situations and/or times of transition like postpartum, post-miscarriage, or perimenopause.
WHAT DOES EACH METHOD OBSERVE
Let’s first start with the biomarkers that each method uses. For standard protocols, Boston Cross Check will require that all users learn how to observe, track, and interpret three primary signs of fertility: cervical fluid*, basal body temperature (BBT), and urinary hormone metabolites assessed by the Clearblue fertility monitor. While all clients do learn how to work with each of these signs, clients are not required to chart with all three of them. Clients may choose to use any two of these indicators in combination in order to achieve a “cross check” to verify the end-of-fertility. Instructors work closely with clients to determine which combination of signs might be best for them, taking into consideration the client’s particular preferences, cycle presentation, lifestyle, financial situation, etc. Many clients do choose to chart with all three at the beginning (which is highly encouraged!), and by having this training they are given autonomy to switch up their charting options whenever their situation or preferences change. Personally, I have used all of the various combinations at different times and enjoy having that flexibility!
And yet, a very similar level of flexibility could be applied with Marquette as well. Contrary to popular belief, Marquette is not simply a “symptohormonal” method. They do offer instruction on BBT, meaning that both a BCC user and a Marquette user could be utilizing the combination of fluid + BBT + monitor! But just as Billings and Creighton are not the same method purely because they use the same biomarker (cervical fluid), BCC and MM are not simply the same method because they provide the same options for biomarkers.
User differences exist in the way the two methods observe and interpret all of these signs; differences which reflect some specific variations in method philosophy and origin. I will discuss those two things below, but for the moment I will say that practical differences exist in the particular categories of cervical fluid, how the method defines a “day” relative to the monitor, and that BCC uses four high temperatures to calculate a shift whereas Marquette uses three. You can also see that BCC has a strong preference for multi-sign charting. BCC does provide instruction on how to interpret single biomarkers, but does not generally recommend them for standard protocols, preferring to have clients choose at least two signs to work with. Marquette, however, offers a standard monitor-only approach which is very popular with many users.
Finally, I should note that both methods will offer alternate options for LH testing and Proov (PdG testing) as needed. BCC can include cervical positioning as an additional sign which does not affect fertility calculations, and Marquette continues to research with Mira as an alternative to the Clearblue monitor.
DIFFERENCES IN METHOD ORIGIN
The Marquette Model was a completely innovative approach to fertility charting, pioneered in the early 2000’s by lead researcher Dr. Richard Fehring at Marquette University’s “Institute for Natural Family Planning” at the College of Nursing. This novel approach sought to utilize readily-available technologies of hormone monitoring to help couples accurately identify their fertile window for family planning. They eventually created a system which incorporated fluid and temperature protocols around the Clearblue fertility monitor, which measures both estradiol and LH. Because of these origins, the Marquette Model continues to be both innovative and research-driven. Its nursing school ties are also reflected in the method’s requirement for instructors to have professional healthcare credentials (a minimum of a BSN).
Therefore, Marquette might be your preferred method if you have a strong desire to receive instruction from a healthcare professional. If you have a specific medical condition that you need help navigating with charting, you can also seek out an instructor who has specifically taken the ‘Medical Applications’ course.
Boston Cross Check’s origins are much different, going back over forty years to the Archdiocese of Boston which developed a method of Natural Family Planning based on a Billings-style approach to fluid in conjunction with a Doering-Roetzer application for temperatures. BCC thus existed as a symptothermal method in the context of diocesan ministry. All of the instructors were local to Boston, and all instruction was carried out specifically within that Catholic context. In 2009, Marquette provided training in the use of the Clearblue monitor to the BCC program, which gave BCC leaders the opportunity to incorporate the monitor into their already-existing system.
Users may find it interesting to envision the Marquette system as being monitor-centered with incorporation of fluid and BBT, whereas the BCC system is symptothermal-centered, with incorporation of the monitor. There are two places where I think this makes a practical difference for the user:
The first is in calculating what constitutes “Cycle Day 1” for each method. BCC will always fall back on a standard symptothermal approach, where CD 1 is the first day of established flow- regardless of what time the flow starts. Marquette has the option to defer to the monitor’s definition of CD1 as the first day when you have a flow within the monitor testing window. To make the example concrete, let’s say that Kelly and Tessa may both start their period at 6 pm on Wednesday. For BCC-user, Kelly, this means that Wednesday is CD1. For MM-user, Tessa, CD1 will be Thursday. If they have both calculated that their start of fertility is CD7, Kelly will therefore begin abstaining a day sooner than Tessa will.
The second difference is the amount of time required to qualify for the start-of-fertility algorithm. Each method will instruct that previous monitor peaks should be included in a client’s calculation for when to begin abstaining if their intention is to postpone pregnancy. Because Marquette centers more around the monitor, it has developed its algorithm around a 6-cycle system (the monitor stores up to 6 cycles worth of data). BCC, however, follows the Doering-Roetzer approach which is a 12-cycle system. Neither method requires a user to have been using the monitor for that amount of time before they can apply method rules (that would be absurd!), but it means that you don’t get the full benefit of the method algorithms until 6 cycles of use with MM and 12 cycles of use with BCC.
Therefore, BCC might be your preferred method if you want something that skews a little more conservative in its calculations; meaning, you might have slightly fewer days available for intercourse when trying to postpone pregnancy. We also include Catholic teaching as standard course materials, although clients can always opt to skip that portion if it does not apply to them.
OTHER KEY DIFFERENCES
Both of these methods can be a good fit for someone who wants:
In situations like this when there are a lot of similarities between methods, the instructor may make a bigger difference than your actual method choice. Regardless of whether you choose MM or BCC, you want to make sure that your instructor is someone you feel comfortable communicating with, during the instruction period and beyond. This means not only that they have a system of communication which works for you (email, Zoom, Voxer, phone, etc.) but also that you can communicate in a way that you feel respected, heard, and understood.
So, how do you choose between them? In addition to the differences mentioned above, here are a few more differences to consider:
BCC, as an organization, is MUCH smaller than Marquette, meaning that it may be harder to find an available instructor and much harder (at the moment) to find support in a language other than English. BCC is also much more standardized, meaning that instructors do not set their own course fees or design their own course materials. Marquette instructors offer a much more varied set of course options, prices, and content. Overall, course fees might be higher with BCC, but in some cases they cover a longer period of time than Marquette, so be sure you understand not only the price, but the duration and depth of service. In either method, please know that instructors care deeply about affordability and accessibility, so you should never let the “sticker price” itself be a deterrent. Instructors are typically happy to work with you on payment plans, or alternate fee arrangements if there is need.
Making the investment in learning a monitor-based method of NFP is a great option for a lot of couples. Obviously, I feel that it works well for my situation—otherwise I never would have kept using it, and I definitely wouldn’t have become an instructor!
But that doesn’t mean that monitor-based methods are always the best route, or that they will always be more effective or accurate than other methods. I firmly believe that the best method is one that will work for you--and in many cases, there are probably a lot of methodological approaches that could be a good fit. So, you shouldn’t worry that you have to investigate absolutely every option and learn every little minute detail to help you find “THE ONE.” Do some preliminary research, but don’t agonize over it.
I also firmly believe that you should never be “stuck” with a method if you find out that it’s not a good fit—whether you find that out after the first instruction session, or twenty years down the road! A wise colleague likes to say: “Remember- you’re married to each other, not your NFP method.” What she means is that you’re allowed to switch methods and even if your instructor is the coolest, most awesome person in the world—you do not owe them your unwavering allegiance! Your instructor wants you to be happy, confident, and capable with your method-- and if that means referring you elsewhere, many providers will gladly do so.
With all of that in mind, happy charting! And of course, feel free to contact me if you have any other direct questions.
*BCC uses the term “cervical fluid” rather than “cervical mucus” out of deference to demonstrated user preference; however, the two are synonymous.
Christina has been an NFP instructor in the Boston Cross Check Method since 2013. She is on a mission to change conversations about body literacy and NFP within the Catholic Church, through innovative lifelong body literacy programming and support... plus apparently this blog.