The problem with predictive period apps...
Would you trust something that was wrong up to 80% of the time?
Are you trusting an algorithm more than your own body?
If you have a natural menstrual cycle, chances are you use a period app to track when you’re likely to get your period. No one likes a surprise bleed! But did you know that apps that have predictive features are a little problematic?
I want to talk about it.
If you have a natural menstrual cycle, what form/s of contraception are you using? If you’ve forgone barrier methods you’re likely using a Fertility Awareness Method, or possibly an app that “tells you when you’re ovulating”.
While FAM methods which track your cycle using bio markers are one thing, putting your period days into an app and waiting for its algorithm to tell you that you are “probably” ovulating is another. And possibly where some misconception around FAM may come from.
If you are using a predictive app… did you know that it will get it wrong approximately 80% of the time?1
Wow, right?
So let’s unpack this a little… using a predictive period app to predict the arrival of your bleed is pretty common, and incredibly convenient. Though, this too has its flaws. One study found that these apps can even struggle with this, with only 6.7% of respondents stated their app always gets the date of their period correct2.
What about using a predictive app to tell you when you’re fertile though? As both studies suggests, it’s a recipe for disaster.
These apps often rely on a calendar method of tracking your cycle, which do not take into account all the different ways that your fertile window may be influenced each cycle.
Just because you ovulated on day 14 last cycle, doesn’t mean you will this cycle!
The journey of ovulation actually begins 100 days before that egg is released, meaning that stress, diet, and numerous other factors from the last four months can be influencing your current menstrual cycle. The body is wise, and will always prioritise survival over reproduction.
This is where Fertility Awareness Methods differ from apps in a really positive way. Learning your body and tracking your bio-markers to know when you’re most likely fertile, and then to confirm ovulation, is not only so empowering for body literacy but has a very high success rate for both contraception and conception.
A big misconception with FAM is that you’re likely to have a surprise baby when you’re trying to avoid one, but when used correctly it’s comparable to many other birth control methods.
The fertility awareness methods are based on using bio-markers to track and chart whats happening across your menstrual cycle. There are several methods including cervical mucus methods such as Billings, urine hormonal monitoring technology methods such as Marquette, then you have temperature only (Natural Cycles uses this), and symptothermal methods also.
Personally, I love the symptothermal as it uses observation of a combination of two or more signs of fertility including temperature, cervical mucus secretions and changes in the cervix, to calculate your fertile window. It means that you have the opportunity to be extra sure and double check yourself if you’re having an ‘off’ day or aren’t quite sure what one bio-marker is doing. (This is also another reason I always recommend to work with a qualified practitioner when first starting out with FAM. It can be a lot to learn, and the support of someone who knows can be incredibly helpful when getting to know your bodies rhythm, especially if you have irregular cycles or other menstrual issues).
Our bodies are all unique, and every cycle is unique. Which is why reading the signs your body is giving you can be so powerful in knowing your fertile window. And unlike the apps, here it pretty much all comes down to human error.
But when are period apps helpful?
I don’t want to demonise period apps. Truly.
They have their place the same way that hormonal birth control methods also have theirs. It all comes down to your personal preference, your comfortability with risk, and your needs. Choosing your method of contraception and how you track your cycle is personal, and it needs to fit in with your lifestyle and needs.
So, while I do not recommend the use of predictive apps for contraception, I think they’re fantastic for tracking your period if you’re using other methods of contraception such as barrier methods. And there are also lots of period apps out there that are solely designed for tracking your cycle. No predictive features whatsover. It’s all about finding the app that you like.
What about Natural Cycles?
The Natural Cycles app uses an algorithm to predict your fertile window based on the basal body temperatures that you log each day. There are a number of issues I have with this:
When tracking your BBT, there can be human error. It needs to be taken at the same time each day as much as possible, and immediately upon waking, in order for it to be accurate. This accuracy, or lack of, can influence the algorithm.
You’re trusting an algorithm to read your BBT measurements correctly. Unfortunately it doesn’t always get it right. I have seen numerous charts in the app where ovulation has occurred, but the temperature shift didn’t fit the algorithm. Then you have women believing that they’re not ovulating, when they are!
It only takes BBT into account. And this is a personal opinion, but I am a fan of using multiple biomarkers.
I have used this app previously, and I did find it convenient and really helpful in getting started! But I never felt confident in relying on it for contraception.
Since then I have moved across to using symptothermal with the Read Your Body app, and am completely in love with my TempDrop for tracking my BBT. Using an app such as Read Your Body, relies completely on you charting your own data. There are no predictive capabilities, and they also don’t sell your personal information or use it for research without permission.
But this does mean that you need to have an understanding of how to chart your menstrual cycle. And, I truly do recommend it! Learning your body’s rhythm is incredibly insightful.
Why chart though?
Fertility awareness methods are becoming a widely used way of avoiding pregnancy, but there are a few other reasons they’re wonderful.
They are a non-hormonal method of contraception, which which relies on body literacy. How empowering! But more than that, this knowledge can be incredibly helpful should you ever need to address menstrual concerns with a practitioner or medical professional, and gives you such a leg up if/when you do choose to conceive. Knowing your fertile window is half the battle when you’re ready to try for a baby!
So in all… are predictive apps bad?
Well, they’re not great.
But maybe they work for you. That’s ok! Just make informed decisions!
And should you ever need support with your menstrual and hormonal health? I got you.
https://pubmed.ncbi.nlm.nih.gov/29749274/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9047811/