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Fertility Apps and Monitors – Can they really help you conceive?

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?

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.

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

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.Lady-Face-on-with-Smartphone

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. 2014; Wark 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.

 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 - $199/£152 + Shipping.

Delivery time - 6-8 weeks after ordering.

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.  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

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 unlikely to work for women with ovulatory problems too.

Daysy offers various customer support such as FAQ’s, video tutorials and downloads and the makers claim the product can be used to avoid pregnancy as well as to achieve pregnancy.

Cost - $328/£251 for thermometer, Free App + Shipping

Delivery time – not stated

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 price, would be a non-starter for many women.

4.  Duo Fertility

Duo Fertility (Duo) is a body-worn Monitor that takes multiple readings of basal body temperature via a sensor situated under your arm and wirelessly transmits this data to the Duo App. Duo is able to predict ovulation up to 10 days in advance based on previous data and confirm that ovulation has occurred. A recent study by Rollason et al. (2014) identified a “worst case” sensitivity of 82%, but was unable to identify accuracy or positive predictive value due to the lack of true negative (anovulatory) results measured in the study. The study concludes that the Duo device “may be useful for identifying ovulation in infertile women with regular cycles”. Duo states that the sensor is suitable for women with PCOS, however Rollason et al. (2014) focused on women with regular cycles and concluded that further research with the ”inclusion of women with irregular cycles, should be considered”.

The Duo App also offers you the ability to manually enter cervical mucus readings, the results of hormone tests, menstruation, etc.

Duo provides customer support by phone or messaging via the App to answer questions and help you understand your data. Technical support is also available.

Cost - $466.87/£359.00 (3 month plan)

Delivery time – Despatched next working day

My opinion – Duo offers convenience and allows a woman to almost forget that she is monitoring her cycle. However the under arm method of recording temperature is not as accurate as other modes and like Ava is subject to external disturbances. The reduced efficacy along with the cost makes Duo a less viable option.

5.  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.

6.  Glow

Glow is a cycle tracking and lifestyle App that allows the user to input physiological data. However, the website tells you very little about what you are actually monitoring in terms of fertility.

Glow has a thriving online community and offers support through FAQ’S. The App claims to also monitor male fertility; I wonder how it does that!

Cost – Free App

My opinion - Glow has been heavily criticised in the recent Fertility App study. It appears to provide more lifestyle data benefits than others and if a lifestyle App is your thing then this might be for you.

7. 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.

8.  Kindara and Wink

Kindara is a cycle tracking App that is used with Wink – an oral thermometer. Wink monitors basal body temperature using a single measurement each day, and 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 unclear whether Kindara works for women with irregular cycles.

Kindara offers support via email only. Charts can be shared with your clinician via the Practitioner Portal.

Cost - $129/£98

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 and Natural Cycles, you are essentially paying for an oral thermometer.

9.  Leaf (Bellabeat)

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

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

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

Cost - $119-199+/£90-152+

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 it is not a true fertility Monitor, and if you really want to get knowledgeable about your cycles and accurately predict ovulation then I strongly recommend looking elsewhere.

10.  Ovacue

Ovacue is a fertility Monitor that measures chloride changes in saliva and vaginal mucus using 2 different sensors. You take one measurement per day. Ovacue monitors chloride changes to predict and confirm ovulation with 98.3% efficacy and giving 5-7 days notice of ovulation can be used for both irregular cycles and PCOS.

Research in to the efficacy of Ovacue concludes that it is able to effectively predict the fertile period but with ‘some degree of variation in predicting and detecting ovulation’ (Fehring 1996).

Ovacue’s customer support consists of FAQ’s, telephone and email support.

Cost - $299/£229

Delivery – Despatched same day

My opinion - Ovacue offers an alternative to body temperature monitoring by measuring chloride. Chloride rises early in a normal cycle but it does so with unpredictable timing, meaning that Ovacue works well for some women but not for others.

11.  Ovatemp and ONDO

Ovatemp is an App that is used with the ONDO oral thermometer to monitor your basal body temperature with a single daily measurement. The App also allows you to track other physiological symptoms such as cervical mucus and the position of your cervix to identify fertile days. The website makes no reference to accuracy, it’s ability to predict or confirm ovulation, or whether it is suitable for irregular cycles and PCOS.

Ovatemp’s customer support is limited, with only FAQ’s available for technical assistance.

Cost – Free App. ONDO out of stock. No price point given.

Delivery – Not stated.

My opinion – Similar to Kindara and Daysy, you are essentially paying for an oral thermometer and App to record your physiological signs and symptoms.

12.  OvuSense

OvuSense is a vaginal sensor that syncs to a smartphone App. Unlike other temperature recording fertility monitors, OvuSense observes core body temperature by measuring in the vagina while you are asleep. The vaginal sensor takes multiple readings throughout the night. OvuSense is able to predict ovulation up to 24 hours in advance, correct 96% of the time, and it detects the exact date ovulation with 99% accuracy (Papaioannou et al. 2012 ESHRE; 2012 ASRM; 2013 ASRM; 2014 ESHRE).Lady-By-Lake-with-OvuSense-on-iPhone

OvuSense is suitable for any woman wishing to conceive and can be used by those women who have irregular cycles or ovulatory issues such as Polycystic Ovaries, PCOS or diminished ovarian reserve.

OvuSense offers 24 hour, 7 days a week technical support by email and on phone call back, and Fertility Nurse 1:1 consultations via Skype or telephone. OvuSense also features an online community with regular online fertility clinics.

Cost - $199/£129 (starter pack including a 30 day subscription), Subsequent subscriptions at $35/£20 per month

My opinion – OvuSense is the only fertility monitor that has the ability to predict ovulation in real time in the cycle – and this is because takes multiple readings of core body temperature in the vagina. The monthly plan offers the ability to cancel at any time which means you’re not locked in if you get pregnant or find it doesn’t work for you. OvuSense support has been well received online.

13.  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 offers email support only.

Cost – Available for Pre-order only. $149/£113

Delivery – 4-8 weeks after ordering

My opinion –The Pre-order availability makes me feel that this monitor is in its early stages of development and it may need further development and improvements before we can see if it becomes a useful tool.

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. I’ve highlighted the importance of measuring temperature and the frequency and location of measurement. I’ve also explained who can benefit from using these products. Hopefully this takes the confusion out of fertility Apps and Monitors a little and helps you to decide which would be best for you.

Book your FREE consultation with the OvuSense Fertility Nurse, Kate -  to assess your fertility potential, answer your burning fertility questions, get recommendations on how to optimize your fertility and have your charts analysed.

If you are an OvuSense customer you are entitled to a FREE 1 hour consult, if you are not currently using OvuSense you can book a FREE 15 minute consultation. Consultations are held by Skype or Telephone. Don't see a time that suits you? Email Kate on kate.davies@fertility-focus.com


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