With advancing technology, we have come to rely on Apps for many things in our lives, be it shopping, music or social media and now even Apps for your fertility! Recently there has been a great deal of media attention surrounding the benefits of Apps and Monitors for fertility, but can they really help you get pregnant and which is the best one to use? I’ve done the research for you and in this blog I review the most commonly used fertility Apps and Monitors, explain what they are, how they work and who they are useful for.

Most importantly, I review their accuracy, including their ability to identify fertile days and ovulation, as well as considering the customer support they offer and the all-important cost. However, before I start it’s really important to explain one crucial difference between Fertility Apps and Monitors.



The difference between Fertility Apps and Fertility Monitors


 My patients tell me that they feel really confused as to which is the best fertility App or Monitor to use. Recent research studies have found that fertility Apps used alone are generally ineffective and do not accurately show a woman when she should try and conceive (Setton et al. 2016; Duane et al. 2016), resulting in even greater confusion.


 There are many Fertility Apps that you can download to use on your smartphone and many are free. Used alone these Apps calculate your fertile time using a calendar method. These Apps rely on a traditional thinking about predicting the ovulation, which is based on the assumption that ovulation consistently occurs 14 days before the onset of your next period – so in the ‘middle of your cycle’ if you have a 28 day cycle. In fact, we now know that only a small percentage of women ovulate exactly 14 days before the onset of their period (Baird et al. 1995; Lenton et al. 1984 a & b). So the calendar method is often really ineffective, and all these Apps are doing is keeping an electronic diary – more detailed and convenient than writing your cycle down on paper but not much more than that.


 Some fertility Apps go a step further by taking into consideration how long your previous cycle lasted.   The problem is because ovulation timing can vary even when you have consistent cycles, data from previous cycles don’t provide enough information to reliably predict individual fertility. Even though there is no doubt that tracking your fertility enables you to take some control and leads to a greater awareness of your cycle, to increase reliability and to be beneficial for conceiving you need to observe the physiological signs of fertility as well. This is where a fertility Monitor comes in.


 Fertility Monitors used in conjunction with Apps offer greater reliability. As well as tracking your cycle, a Monitor gives you the ability to track your progesterone level by measuring temperature.   There are two types of temperature which can be monitored: basal body temperature or core body temperature.


 The most accurate method of tracking basal body temperature is by measuring in the mouth.   A number of skin based monitors also exist but recent studies have shown this is not a particularly accurate method (Rollason et al. 2014Wark et al. 2015) as it is subject to temperature disturbances due to environment and illness.


 Studies have shown that the most accurate method of tracking temperature is to measure core body temperature in the rectum or vagina. The ability of core temperature, as opposed to oral or skin based temperature, to more accurately track the level of progesterone and to provide real time prediction of ovulation is confirmed by Coyne et al. (2000)




Here’s why measuring temperature is a good idea:


Progesterone is released during the process of ovulation in each cycle, and your progesterone level will normally stay high for the rest of your cycle after ovulation. As progesterone is released, it causes your body temperature to rise, and the rate of rise of temperature is directly linked to the rise in progesterone level. So measuring temperature allows us to see when ovulation occurs. Detecting if and when you ovulate is vital to increase your chances of conception.

The key things to consider in tracking temperature is how often the measurements are taken, when the measurements are taken (overnight or first thing on waking is when the temperature is at its most stable), and most importantly the location of the sensor.

Here’s a relative scale of accuracy of measurement for the location of temperature sensors.  It’s a representative picture to give you an idea of how sensor locations compare based on scientific data discussed in this blog, but please note it is not on a measured scale:

These factors and the clinical evidence is discussed in reference to the Monitors outlined below.

Another recognised fertility indicator is cervical mucus. Observed throughout the cycle, cervical mucus changes in appearance and consistency and stretchy, egg white secretions indicate peak fertility. Some Apps allow you to record these secretions.

Your fertility can also be monitored by testing the levels of luteinising hormone (LH) present in your urine using ovulation prediction kits or monitors. The LH surge occurs approximately 24-48 hours prior to ovulation. However ovulation predictor kits and monitors have been widely documented to produce ‘false negative’ results meaning that you get no indication of ovulation (Lloyd et al. 1989, Irons et al. 1994 and Arici et al. 1992)

The Most Commonly Used Fertility Apps and Monitors (in alphabetical order)

1. Ava

Ava is a wearable wristband worn at night, which is used in conjunction with an App. The makers claim the Monitor observes physiological data such as skin temperature on the wrist to monitor progesterone levels, as well as pulse rate, heart rate variability, profusion, bioimpedance, breathing rate, heat loss, movement and sleep and state that ‘some of these parameters change in correlation with reproductive hormones’. Ava identifies 5.3 fertile days per cycle, with 89% efficacy but is unable to detect ovulation. We can assume it takes multiple readings of these parameters.


You can use Ava if your cycles range between 24-35 days. However, if you have an ovulatory issue such as Polycystic Ovarian Syndrome (PCOS), then Ava is unlikely to work for you. Ava provides customer support in the form of FAQ’s and email support. The makers don’t say whether the email support is clinical or technology based.


 Cost – £249 + Shipping.


 Delivery time – 3-5 business days.


 My opinion – Ava is a combination of a lifestyle and fertility monitor. If monitoring your general health is the most important aspect for you then you might like this but due to it’s low efficacy and inability to detect ovulation, I wouldn’t recommend it for fertility.




2. Clearblue Fertility Monitor


The Clearblue Fertility Monitor detects changes in two key fertility hormones luteinising hormone and estrogen present in the urine. It is able to identify 6 fertile days and states it is 99% accurate in detecting the LH surge.


 You can contact Clearblue via Live Chat and email or by the telephone careline where women can get both technical support and advice on their journey to parenthood.


 Cost – Clearblue Fertility Monitor £87.67 subsequent ovulation tests from £27.99-42.59


 My opinion– The Clearblue monitor offers women a practical and clear way of identifying the fertile. The monitor however, is not suitable for women with PCOS due to elevated levels of LH or women who are using fertility treatment medication such as Chorionic Gonadotrophin (HCG) or Clomid as this can cause elevated estrogen levels. For those reasons, this monitor would not be accurate for a large percentage of women who are trying to conceive.


 To achieve accurate results you need to test on multiple days leading up to ovulation. This can be inconvenient but also requires purchasing subsequent ovulation tests.




 3.  Clue


 Clue is a cycle tracking App that uses the calendar method to predict your cycle. You are also able to input any symptoms you experience such as bleeding, pain, emotions and energy.


 Clue offer App technical support only via their website.


 Cost – Free App but you can upgrade your plan for £0.99 per month to access more information


 My opinion – If you want to get more knowledgeable on your cycle and understand more about your body then you may like using this App. It is user friendly and nice to look at but it is it unlikely to help you conceive any more than using a paper diary or wall calendar.




3.  Daysy


 Daysy is a fertility Monitor and App that monitors basal body temperature with one quick reading on waking, using an oral thermometer. The makers claim the monitor identifies fertile days with 99.3% accuracy and learns your individual cycle pattern, which it then uses to forecast your next cycle. Daysy does not appear to confirm ovulation. The product comes from the makers of BabyComp/ LadyComp which was included in an original paper on cycle monitors by Freundl et al. (2003), showing similar accuracy figures.


 The Daysy App offers you some fun features such as a gender prediction tool, however research does not support gender prediction based on the timing of sexual intercourse in a given cycle (Wilcox et al. 1995). The App also allows you to share information with your partner to let him know when it is ‘time to get down to business’! Unfortunately, you can’t use Daysy if you have irregular cycles, and therefore it is not suitable for many women.


Daysy offers telephone customer support, video tutorials and downloads and the method can be used to avoid pregnancy as well as to achieve pregnancy.


 Cost – $330/£256 for thermometer, Free App + Shipping


 Delivery time – 2-5 days


 My Opinion – Daysy offers an 21st century alternative to manual temperature charting but it is debateable whether it does anything more than your average ‘under the tongue thermometer’. Oral temperature recording is subject to environmental disturbances and illness, and it is therefore not the most accurate method. This, combined with the inflated price, would be a non-starter for many women.


 4.  Fertility Friend


 Fertility Friend is a widely used cycle tracking App that incorporates manually entered oral temperature readings and other physiological data in to its system. Temperature readings are taken using a basic oral thermometer and users are encouraged to input cervical secretions, sexual intercourse and other physiological data.


 The App is able to confirm ovulation based on the manually entered temperature readings and offers an indication of fertile days but is unable to predict ovulation.


Wise et al. (2015) concluded in their recent randomised trial that in a population of women who had been trying to conceive for ≤6 cycles at study entry there is “little evidence that randomization to the Fertility Friend menstrual cycle charting software program influenced fecundability among pregnancy planners participating in an incentive-based internet study.” It does go on to say that “among those who had already been trying to conceive for 5-6 cycles at enrollment, assignment to Fertility Friend was associated with faster conception.” The study showed a ~15% improvement in that group, which is almost certainly down to the charting creating a better overall understanding of their cycles. However, it is difficult to translate this result into a greater likelihood of conception in women who have any kind of irregular cycles and/ or ovulation. As with any basal body temperature monitoring, the temperature is just as prone to variations for women with irregularity, and are not able to predict ovulation in real time.


 Fertility Friend offers support via access to a community and helpful videos.


 Cost – Free. There is a cost to upgrade to access other features


 My opinion – Fertility Friend offers a woman an easy and convenient way of charting her cycle and fertility indicators. However, having looked at many Fertility Friend charts, it is common for me to see inaccuracies with the confirmed date of ovulation and fertile days. This is most often with an earlier ovulation date than would be expected by observing the temperature data by eye. This may be down to the detection algorithm Fertility Friend employs, but either way the literature would indicate as with other Apps that there is little benefit in efficacy compared with manual charting.


 5. Flo


 Flo is another period tracking app and an ovulation calendar. It uses AI to increase its prediction accuracy to help women understand their cycle.


 The App offers daily health insights and analytical reports on your period and lifestyle. The App provides support via email and community groups to engage with on topics from healthy eating to anxiety and depression. However at the time of writing these groups do not seem active


 Cost – Free App but £7.49 per month to unlock unlimited access for further support


 My Opinion – The Flo App offers you a great deal of advice at your finger tips via their many informative articles. It is disappointing to see that the Flo community is not active; this could be because it’s a recent initiative, as it is a great idea. However there is no getting away from the fact that, like Clue, this is yet another calendar tracking device and as such is not reliable at identifying ovulation.


 6. FitBit


 With the FitBit Versa watch, Charge 3 or Ionic devices you are able to track your female health via the in-app experience. It is designed to help you learn more about your menstrual cycle and your body.


 The App allows you to log your period, record symptoms and receive notifications of when your period is due. The App is also able to give you an average estimated ovulation day.


 Fitbit has a Female Health Forum Community but it appears that this is for technical help rather than female health support and advice.


 Cost – Prices vary depending on device from $170.75- 328.00/£129.99-249.99


 My Opinion– FitBit offers you the ability to get to know your menstrual cycle and symptoms so you can better understand how your menstrual cycle effects your energy levels, mood and general wellbeing. It also helps you to plan around your cycle, such when you’ll have better energy and when a duvet day is best! However, FitBit does not use any physiological data such as temperature and is therefore a calendar tracking advice, and as such is not able to reliably predict ovulation or when your next period will occur.




6.  Glow


Glow is a cycle tracking and lifestyle App that allows you to input physiological data such as temperature, cervical mucus and moods. Using a calendar method Glow is able to grade your chance of pregnancy at a given day and notifiy you when your period is due.


 Glow has a thriving online community and offers support through FAQ’S. The App also includes an add on Glow Fertility Program which offers discounted fertility treatments and egg freezing with featured US based clinics and showcases top US fertility doctors.


 Cost – Free App but £7.99 per month to unlock advanced charting and more tools.


 My opinion– Glow has been heavily criticised in the recent Fertility App study as one of the worst fertility Apps. It may provide you with some lifestyle data and if a lifestyle App is your thing, then it might just be for you but don’t even consider it to help you get pregnant. Whilst it is available in the UK it does appear to be more US audience based.




7. Kindara and Wink


 Kindara is a cycle tracking App that is used with Wink – an oral thermometer. Wink monitors basal body temperature, which then syncs this information with the Kindara App on your smartphone.


 Kindara is able to identify your fertile time and confirm ovulation but offers no ovulation prediction in real time. Kindara states that Wink is the most accurate body temperature thermometer on the market but offers no efficacy rating for it’s ability to accurately identify the fertile time or confirm ovulation. It is unclear whether Kindara works for women with irregular cycles.


 Kindara offers support via email but also offers access to 1:1 practitioner teaching for an extra $154. Charts can also be shared with your clinician via the Practitioner Portal.


 Cost – Free App but £4.99 per month to track unlimited data.


Wink Thermometer $129 plus shipping


Delivery time – Not stated


 My opinion The Kindara App and Wink thermometer are certainly appealing to the eye. The thermometer is easy to use and read however like Daysy, you are paying for a glorified oral thermometer with all the inaccuracies this mode of temperature recording has.


 8. Leaf (Bellabeat)


 Leaf, made by Bellabeat is a reproductive and fitness health tracker in the form of wearable jewellery. Leaf syncs with your smartphone to give you information about your cycle and period as well as tracking your activity, stress levels and sleep.


 Leaf uses the calendar method to predict ovulation, based on your previous cycle and the date of your last period.


 Leaf offers support via FAQ’s, a telephone call back service and pictorial tutorial to help with the technical side.


 Cost – Free App. Leaf jewellery £77 plus shipping.


Delivery time – Not stated


 My opinion– If you are looking for a nice piece of jewellery and a lifestyle tracker then Leaf might be just what you need. However if you really want to get knowledgeable about your cycles and accurately predict ovulation then I strongly recommend looking elsewhere!


 9. MyLotus


 My Lotus is a personalised fertility testing device and App that allows you to monitor your luteinising Hormone (LH) levels and how this links to ovulation and the identification of your fertile days.


 MyLotus measures how much LH is present in your urine. LH levels increase as you prepare to ovulate. All women have a different baseline LH level and MyLotus is able to provide a measured (quantitative) result that differs from traditional (qualitative) ovulation tests. MyLotus state that therefore the device is suitable for women with irregular cycles and women with PCOS.


 MyLotus offers technical support via FAQ’s and the ability to report a technical problem within the App. However it does not appear that MyLotus offers any clinical support


 Cost – MyLotus Starter pack £349.00 thereafter £54.00 for 20 ovulation tests. MyLotus App is free and can be used as a stand-alone calendar tracker.


 My opinion – MyLotus is certainly the next generation of ovulation prediction using LH in the urine. The ability to identify LH increase from a woman’s normal baseline is likely to improve efficacy of the traditional LH testing. However it is evident that MyLotus was tested on a very small sample size of 111 women over a 12 week period (Note there is further reference on the website to a sample size of 64 women and therefore exact sample size is unclear).


 MyLotus claim that the device is suitable for women with irregular cycles and PCOS however there is no reference to the device having been tested by women with these cycle characteristics and therefore it is difficult to substantiate this claim.


 Costs can escalate, as subsequent ovulation tests are needed. Some women may find it inconvenient to test multiple times.


10. Natural Cycles


 Natural Cycles is an App that is used with a basal body temperature thermometer. A single temperature reading is taken first thing in the morning and this information is then downloaded to a smartphone.


 Natural Cycles uses an algorithm that quickly learns your cycle and the company state is able to detect and predict ovulation and when you are fertile. Two clinical studies in to the use of Natural Cycles conclude that this method is accurate in identifying a users ovulation day and fertile window.


 Natural Cycles offers FAQ and email support.


 Cost – $28.90/£23


 Delivery Time – 3-5 days in Europe and 6-7 in the rest of the world


 My opinion – If you are looking to monitor basal body temperature and would like an easy to use technology based option, then this might be right for you. It’s inexpensive thermometer makes it more affordable than Wink or Daysy, however this thermometer is measuring basal body temperature only and not the more effective core body temperature.


 11. Ovacue


 Ovacue is a fertility monitor that monitors both saliva and vaginal mucous via 2 different sensors, requiring one measurement per day. Ovacue monitors electrolyte changes in both saliva and vaginal secretions to predict and confirm ovulation with 98% efficacy and giving 5-7 days notice of ovulation can be used for both irregular cycles and PCOS.


 Ovacue’s customer support consists of FAQ’s and live chat technical support only.


 Cost – $269 including shipping


Delivery – Not stated


 My opinion– Ovacue offers an alternative to body temperature monitoring, however the efficacy of monitoring saliva ferning to predict ovulation is not supported by clinical research (Guida et al 1999, Fehring and Gaska 1998). On the other hand, observing vaginal secretions does provide an accurate interpretation of fertility, however the effective monitoring of cervical secretions can be done manually, avoiding the need for expensive monitoring equipment.


 12. OvuSense


 OvuSense is a vaginal sensor that syncs to a smartphone App. Unlike other temperature recording fertility monitors, OvuSense observes the more accurate core body temperature whilst you are asleep, taking multiple readings throughout the night. OvuSense is able to predict ovulation up to 24 hours in advance with 96% accuracy and detect ovulation with 99% accuracy (Papaioannou et al 2012).


 OvuSense is a class 2 medical device and is suitable any woman wishing to conceive and can be used for irregular cycles, PCOS and diminished ovarian reserve.


 The OvuSense individual customer support is extensive with 24 hour, 7 days a week technical support, Fertility Nurse 1:1 consultations via online video, email support and a thriving online community with regular online fertility clinics. OvuSense also offers 100% money back guarantee if ovulation is not detected after 6 months of use.


 Cost – $99/£79 Starter pack with 30 day App subscription Free Delivery


$299/£199Starter Pack with 12 month App subscription Free Delivery


Delivery – Next Day


 My opinion– OvuSense is the only fertility monitor that has the ability predict ovulation in real time. This gives women timely and accurate cycle and ovulation information, empowering them to plan and take back control. The monthly plan offers true flexibility, especially if you want to take time out of trying for a month or two. The OvuSense support package is unrivalled and all together OvuSense offers clinically proven accuracy and value for money. Compatible with both iPhone and Android.


13. Tempdrop


 Tempdrop is a sensor that uses skin temperature measurements to determine your personal nightly temperature and use this information to track ovulation and determine the most fertile days in a cycle.


 Tempdrop is worn under your arm during sleep using the Tempdrop armband. Each night, Tempdrop collects thousands of data points on your body temperature and sleep motion and then in the morning syncs with the Tempdrop App.


 Tempdrops support is limited and consists of FAQ’s on their website and App and an in App chat service.


 Cost –  $149-249. Free App


Delivery – 4-6 weeks


 My opinion– It is unclear from the website if Tempdrop has been tested to accurately identify ovulation or the fertile time. Tempdrop quote a study byRubia-Rubia et al. (2011)where the efficacy of skin temperature recording was compared to other methods. Skin temperature recordings were not found to be as accurate in measuring body temperature than other methods but it was found to be convenient, easy to use and comfortable. Due to the inaccuracies of skin temperature monitoring this is not a method I would recommend.


 14. Yono


 Yono is an in-ear fertility monitor and App. Yono monitors your basal body temperature overnight whilst you sleep using a small ear bud. There is little clinical research in to the efficacy of the tympanic (in-ear) route of temperature measurement for fertility. A recent study by Niven et al. (2015) concluded that peripheral thermometers ‘do not have clinically acceptable accuracy’ and should not be used when accuracy is important.


 The website states that Yono can be used for ovulation prediction and that it identify the fertile days each cycle. There is no reference to accuracy or if the monitor can be used for women with irregular cycles or PCOS. Yono’s support is via email, phone or from the FAQ page.


 Cost –$149 Free shipping


Delivery – not stated


 My opinion– With dubious accuracy given the in-ear route, this is not a monitor I would recommend. The device is not compatible with android devices.


This blog has highlighted the differences between fertility Apps used alone and fertility Apps used with monitors, as well as explaining how each one works, who can use them and what they offer you. Hopefully this takes the confusion out of fertility Apps and monitors a little and helps you to decide which would be best for you.






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