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What's behind your fertility app's algorithm and is it the right one for you?

It is easy enough to download an app, insert a medical device, like OvuSense or OvaCue, in your vagina overnight, or put on a bracelet, like Ava, overnight — all with the aim to track your fertile window in hopes of timing intercourse to become pregnant or avoid pregnancy. However, women often rely on these devices without understanding how their body works and what exists behind each app’s algorithm.

Fertility Tracking Apps

In order to properly evaluate what app or device is right for you, it is critical to understand the foundations behind the amazing machine — the woman’s body. Doing so allows you to properly evaluate a given app’s or device’s effectiveness rather than being subjected to good marketing.

Additionally, tracking is not just about trying to get pregnant or avoid it altogether. Tracking informs us of potential health concerns. Sadly, however, many of these concerns aren’t even discussed or diagnosed until a woman struggles with infertility. This leads to to suffering, grinning and bearing pain for years because no one is listening, or worse yet, thinking a given symptom is normal and not knowing something can be done about it.

Imagine, instead, looking at these tracking tools in a broader sense — as a way to easily monitor your body so that you can be aware of its rhythm, identify when it is out of rhythm, and have ideas around what could be wrong. This would lead to more effective conversations with your doctor and in fact, the awareness would empower you to stand up for yourself if your doctor dismissed your symptoms. And yes, these conversations could also be about your fertility.

Repeatedly, when speaking to doctors and patients, I hear stories like these.

“My doctor told me at 18 I’d never have kids, but at 39 I was diagnosed with PCOS and was successfully treated for it. I spent all this time avoiding relationships because I did not want my potential partner to miss out on kids.”

“I have severe cramps and my doctor told me to take ibuprofen. Several doctors later, I was diagnosed with endometriosis.”

So how do I know what my body is telling me?

Toni Weschler, MPH, the author of Taking Charge of Your Fertility, wrote what is essentially the Wikipedia for understanding human reproduction, educating us about the Fertility Awareness Method (FAM). It should be mandated reading for every woman! She even wrote a teenage-friendly version, Cycle Savvy.

There are three main measurements to the Fertility Awareness Method:

  • Basal body temperature (BBT), or waking temperature

  • Cervical position

  • Cervical fluid

Each of these provide clues about your body and can help diagnose:

  • Anovulation (lack of ovulation)

  • Late ovulation

  • Short luteal phases (the second phase of the cycle)

  • Infertile cervical fluid

  • Hormonal imbalances (such as PCOS)

  • Insufficient progesterone levels

  • Occurrence of miscarriages

Additionally, the following gynecological problems can be more easily diagnosed:

  • Irregular or abnormal bleeding

  • Vaginal infections

  • Urinary tract infections

  • Cervical anomalies

  • Breast lumps

  • Premenstrual syndrome

  • Miscalculated date of conception

Prior to the existence of apps, the only way to monitor your BBT, cervical position/fluid was via the arduous task of paper charting. Now, we have the benefit of entering data into an app like Clue, Daysy, or Kindara (some of which have their own Bluetooth thermometers) or let a device like Ava, OvaCue, or OvuSense measure our BBT for us, which makes them an incredibly helpful replacement to paper charting. However, they are not a substitute for FAM awareness.

How does/should your app properly apply FAM?

Do you enter all FAM data points into your app? What does the app’s algorithm do with the data you do (or don’t) enter? I’ve tried to research the algorithms, but they are proprietary. Some, like Ava, at least state what they are measuring, however. Perhaps it helpful to provide suggestions on what these algorithms should account for.

Important facts about FAM your app should have as part of its data entry points and algorithm:

  • Your temperature rises every hour, so if you wake up at significantly different times, note the time your temperature was taken as it may explain anomalies to your pattern

  • Stress, alcohol, illness, moving and travel can impact your BBT, so it is important to notate such events

  • If you are a shift worker, traveling to a new time zone or dealing with daylight savings time, your BBT is impacted

  • If you have been trying to conceive for over 6 months if you are under 35 and over 1 year if you are over 35, you should see a doctor about your fertility. Does your app give you a push notification about this?

If FAM seems overwhelming, consider this

FAM allows you to understand your body’s rhythm so that you are clearer when it is out of rhythm. Lara Briden, ND, author, of The Period Repair Manual suggests charting to get an idea of your rhythm and if something seems off, chart for a few months to see what clues your chart may tell you. This would allow for more effective conversations with your doctor (assuming they studied FAM in school). This is a great suggestion for someone who may feel overwhelmed by charting day after day. Sometimes, too much rigor is anxiety provoking and charting as needed may feel more investigative.

Why do women not know about the Fertility Awareness Method (FAM)?

Unfortunately, “Doctors are still seldom taught a comprehensive version of this scientific method in medical school,” Weschler writes. A recent study shared traditional medical schools often don’t teach FAM, yet it acknowledges “these methods remain a sought after and valid form of family planning.”

When doctors are aware of FAM, they don’t always recommend to patients because “it’s complicated and difficult to use, requires high intelligence in order to apply, and takes too much time to learn and practice.”

This is insulting because from what I have seen, women struggling with fertility are the most self-aware individuals and incredible well-researched in the area of human reproduction. I would also bet that if provided the right education, even those not struggling with or concerned about fertility, would use FAM, especially now that we have apps.

Yet this is bigger than whether or not doctors are trained. Weschler states, FAM is “not better known or promoted for birth control [because] it is not as profitable for either physicians or pharmaceutical companies, such as those that produce the Pill or IUDs.”

We should all be grateful for the technology available to us, but let’s not have them be a substitute for self-awareness.


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