What is a Fertility Monitor?


If you’re trying to get pregnant you’ll find that you’re suddenly having to learn a lot about fertility: you can give yourself the best chance of conceiving when you want to by making sur you’re trying at the right time. Your ‘fertile window’ is the few days each month, defined by the lifespan of both egg and sperm, and anchored by ovulation, where having sex can result in conception.

If you’re living with a condition like Polycystic Ovary Syndrome, which can delay or even prevent you ovulating in any given cycle, knowing when you’re ovulating and predicting when you’re going to ovulate is even more important! It happens more rarely for you, so each time needs to be flagged as far in advance as possible to give you the chance to take advantage of it.

There are more and more devices available that promise to help, and if you don’t exercise a bit of critical and sceptical thought you could spend a great deal of money before you find something that actually helps. Today we’re taking a look at what’s available to help you decide what really is an advanced fertility monitor and what’s just a gadget.

Different Approaches

A ‘fertility monitor’ is essentially any device that uses existing methods of tracking and predicting your fertility (specifically, when you ovulate) but automate a lot of the work. You still have to provide the necessary input but the device processes the data and gives you day to day results and longer term predictions.

They can convenient, but they’re only as good as the method they’re using: don’t be dazzled by design. However space-age the monitor in question looks, if it’s not giving accurate results it can’t help, and you’d be better off with a thermometer and a notebook.

There are two main approaches fertility monitors take: hormone tests and BBT (Basal Body Temperature).


Hormone based monitors are more sophisticated versions of the widely available Ovulations Predictor Kits (OPKs). They worked by testing for the Luteinising Hormone (LH) that spikes to stimulate ovulation – this works similarly to a pregnancy test, testing urine by having the user pee onto a stick or in a cup. Some have a second string of testing, using saliva to test for oestrogen levels.

Unfortunately if you have any kind of condition that affects you hormones – or simply a naturally high or low level of that vital LH chemical you can false positives or false negatives, and any advance predictions are distorted!


Your Basal Body Temperature is a good indicator for when you’re ovulating as working with this metric requires delicate measurements and processing statistics, a fertility monitoring device can really add some value here! A device makes it easier to get accurate readings, and understand the results, giving this data real predictive power! A BBT based device is a great option.