What's the difference?
There are a lot of fertility charting methods out there, and many share similarities. It can be fascinating to delve into the differences between sympto-thermal methods! I’ve been recently asked again to explain the difference between BCC and Marquette. I’ve attempted this many times (in various levels of detail) over the years in comments on threads in social media charting groups. Things have changed over time, so some of my old comments are no longer accurate, but I don’t have time to keep attempting an answer to the question! It’s time to put this somewhere more stable, in a way that can be corrected and updated. I’ve spoken with multiple Marquette instructors, but would be very happy for others to message me with clarifications, updates, more details, greater nuance, etc. so this resource is as accurate as possible. I may not get everything right, and I don’t mind errors being pointed out, because it leads to improvement.
Let’s start with origins. BCC began as a sympto-thermal method in the late 1970’s, originally using a Billings Ovulation Method approach to cervical mucus and a Döring-Roetzer BBT approach. The Marquette researchers were affiliated with the Creighton Model before they began the INFP at Marquette and developed a new method in 2002. Dr. Richard Fehring had been interested in femtech for quite some time and had published evaluations of new fertility monitoring technologies, and finally saw something truly promising in the Clearblue fertility monitor. In 2009, Mary Schneider of the INFP at Marquette generously traveled to Boston to teach the BCC instructors how to use the Clearblue monitor, and the NFP coordinator in Boston perused the published research and consulted with the researchers on how BCC might best integrate their research into BCC's pre-existing STM approach.
Because BCC incorporated Marquette research into hormone monitoring, and Marquette incorporated some STM research and practices (in consultation with figures in the STM world) into their sympto-hormonal approach, there are a number of similarities between methods. Both allow for cervical fluid observations, at home urinary hormone testing, and BBT. The only sign that BCC allows that Marquette does not support is charting changes at the cervix. This is a supplementary sign only in BCC and the post-peak count is never based on this alone. Reasons to - or not to - include cervix observations vary by method. In mucus-only methods, there can be concern that observing mucus before it travels past the pockets of shaw in the vaginal canal may be misleading, and their research for family planning purposes is based on external observations only. There is a chance of irritation or infection, and no good published evidence cervix checks are widely effective in helping women determine their fertile phase. BCC allows it because the chance of irritation or infection is small given good hygiene practices (keeping nails well trimmed and washing hands before and after), the biological changes at the cervix are well documented, and it might be helpful to some individual women.
BCC trends a little more conservative in some areas. For example, the BCC algorithm is more conservative in that the final/complete algorithm is based on twelve cycles of data, rather than six, which has been shown in some STM research on BBT algorithms to be a little more effective. With BCC's strong sympto-thermal background, we carry over some specialized temping rules based on seminal research on BBT. Boston Cross Check also has a number of other approaches to use when determining the start of the fertile window, which include things like the shortest ever cycle rules, also based on seminal NFP research. So there are more options for determining the start of the fertile window.
Marquette’s temping rules look for three temps 0.2°F above the previous six. BCC also looks for the 0.2°F sustained rise, but BCC temping rules include waiting for the morning of the fourth high temp rather than evening of the third. BCC formally supports Tempdrop use, so this approach may have helped to mitigate any effect of Tempdrop's original retroactive algorithm might have (no longer a consideration as of December 2022 when the retroactive algorithm was retired) and any "shifty shifts" that could occur. It's also a little more conservative for traditional temping as well, and that is to allow users to confidently provision for temps that are 0.2° higher above the pre-shift six temps, without requiring that the third high temp be 0.4° degrees higher, which you can find in the rules of some other brands of sympto-thermal methods, which are more complicated to master.
BCC’s standard approach to “Stage 1” of the postpartum transition (what Marquette terms “cycle 0”) may be a bit more conservative as well, with the standard instructions having monitor day 6 a day of abstinence even if tested low, to allow the monitor to set a baseline for that testing cycle so that lows are trusted only when the monitor has both the preset threshold and personalized rise from baseline in effect, for whatever potential increase in sensitivity that affords. This was implemented after BCC instructors observed patterns of lone lows on monitor day 6 in postpartum women, particularly close to fertility return, and reviewing the charting noted the increased potential for pregnancy if that low day were always trusted.
BCC instructions are to reset the monitor after peak in Stage 1/cycle 0 for any woman who does not have ovulation confirmation, in order to begin testing again for when the post-peak abstinence counts end. BCC does not assume infertility for the week after the post-peak abstinence count in Stage 1/cycle 0. But if you test and get lows, those are available.
BCC advises that a single Proov positive result after peak is typically sufficient to confirm ovulation in most situations (accounting for DHEA or progesterone supplementation, and possible ovarian cysts.) This is based on the published research on Proov tests and on Proov's internal clinical research. We consulted with the Proov founder for an understanding of what range of serum progesterone levels is associated with their PdG results, and correlated that with established research from Hilgers on serum progesterone levels and the end of the fertile window.
For both methods, it is likely standard to advise completing any cervical fluid or monitor peak count underway when a Proov+ occurs. BCC definitely does, since that is exactly how a cross-check is designed to work! I am uncertain of Marquette’s current formal approach to Proov, but some Marquette instructors have advised that a single Proov positive is sufficient following peak, but that three consecutive Proov positives should be seen if there was no preceding peak.
Marquette requires its instructors have a relevant medical background in order to take their instruction training through the school of nursing. BCC does not require this, although it has some instructors in the health and medical fields. The training approaches will certainly be different between the methods. BCC fees and instructor materials are standardized, whereas Marquette instructors have more leeway in setting fees and creating or determining what materials they will use and how they will structure classes. While BCC fees are standardized, instructors do have the freedom to do pro bono work, offer grants or financial relief to help clients in need, and often do this. This is something done by many Marquette instructors as well. BCC does not currently have a self-paced online course or videos, or group classes. Instruction is done personally with each client (or client couple). Small group classes in BCC are likely to be used in future in Catholic dioceses where marriage preparation requires a course in NFP, otherwise there’d be a bottle-neck holding up weddings! Of interest to Catholics, both methods have long held USCCB certification. BCC reapplied for certification after the method changed hands and was no longer diocesan affiliated, and received USCCB certification mid-2023.
What does this all mean? It means you have more choice. There are variations within basic categories of methods based on what signs they observe. There are multiple sympto (mucus) methods, multiple sympto-thermal methods, and multiple monitor methods, all with their own takes on how best to apply the art of fertility charting to the biological science. Fertility charting doesn't come in just 3 primary colors - you get to decide if you like turquoise or teal best. (I'm on #teamteal)
