Your OvuSense questions answered

FAQ Topics

Technical questions about OvuSense Sensor and App

    Is my mobile phone and tablet compatible with OvuSense App?

    The OvuSense App is available for Android and Apple devices.

    The OvuSense App is compatible with Android devices that have built in NFC (near field communication). However, please note that the OvuSense App is not compatible with Huawei P8 or P9 models.

    For Apple devices, the OvuSense App is compatible with iPhone: 7, X and later models with built in NFC running iOS version 8 or later:

    Why did my OvuSense App not give me a confirmation of ovulation?

    Over a number of years, clinical studies have identified that a sustained rise in temperature is associated with ovulation [1].  OvuSense builds on this original clinical work with a set of new algorithm methods which predict and confirm the date of your ovulation in each cycle.   In general, an increase of at least 0.3 degrees Celsius over three days indicates ovulation, though your pattern may vary. When OvuSense confirms your ovulation, it’s doing so on the basis of matching your current cycle pattern against the pattern proven in our clinical studies. If you have not received a confirmed ovulation then there are not enough data to provide evidence that ovulation occurred in this particular cycle. You may still see that a rise has occurred, and that could mean you have in fact ovulated but the rise was too 'slow'” to trigger the detection rule.

    [1] Barrett JC Marshall J (1969); McCarthy and Rockette (1983)
    What is the difference between a realtime prediction and confirmation from the OvuSense App?

    OvuSense uses separate algorithm methods for predicting and confirming ovulation. By using data from the OvuCore Sensor, your OvuSense App is able to tell you in advance during your cycle that ovulation may be about to happen using the current cycle data - that's what we call 'realtime prediction' and it's not possible using any other app or monitor that uses temperature.

    Along with your prediction, your OvuSense App will show a green shaded area of your 'ovulation window' on your graph, with the predicted day of ovulation shaded as a blue vertical line. The ovulation window is the four days immediately around ovulation, from one day before until two days after ovulation.

    The OvuCore Sensor data is then used by the OvuSense App to confirm the exact date of ovulation - again no other app or monitor can do that. Although other apps or monitors may provide you with an ovulation date, clinical data show the confirmations are only based on a window during which ovulation is detected to have occurred.

    The prediction method using the OvuCore Sensor has a clinically proven sensitivity of 89% meaning that it picks up 89/100 ovulations in advance, but a positive predictive value of 96% which means that 96/100 predictions it makes are correct. Combining the data gives an overall accuracy figure of 89% [1]. The OvuSense App algorithm that interprets the OvuCore data was deliberately designed not to give you the false hope of an ovulation if it might be wrong and that’s why it misses out some ovulations, but is good at getting them right when it does show one. The prediction message appears up to one day in advance of ovulation.

    Confirmation of ovulation with the OvuCore Sensor has a sensitivity of 99% meaning it picks up all but 1 in every 100 ovulations, and a positive predictive value of 100% meaning it’s gets them all right. Combining the data gives an overall accuracy figure of 99% [1].

    If you're using the OvuFirst Sensor, then your OvuSense App can provide you with a confirmation of your ovulation window and a suggested date of ovulation. It does this with over 90% accuracy. [2]

    The confirmation of ovulation message is displayed by your OvuSense App 2-5 days after you have ovulated, by which time it has much more data to make the calculations and that’s the reason why it’s able to pick up more ovulations, more accurately.

    [1] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy, sensitivity and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014). [2] Internal Fertility Focus side by side study of OvuFirst and OvuCore Sensors (2021).

    What is the fertile window shown by my OvuSense App?

    The Fertile Window is shown from cycle 2 onwards if you received confirmed ovulation in the previous cycle. The Fertile Window is shown on your graph as an orange shaded area, with the predicted day of ovulation shaded with a blue vertical line. This window is the eight days when you are most likely to be able to conceive, from five days before ovulation until two days after ovulation. The window is based on the day of ovulation from the previous cycle, so if your cycles vary in length it will be less useful to you.

    I had a fever last night, will that affect my temperature readings?

    If you have a fever for two or more days you should stop using OvuSense until you are feeling better again. A short fever may show as a ‘spike’ in temperature on your chart. However, the OvuSense App has been designed with an intelligent filtering system that excludes ‘spikes’ when calculating ovulation so it should not affect your results. If it helps you to remember, mark the fever in your OvuSense App events but note that this information is not used by the OvuSense algorithm methods to change calculations.

    I drank alcohol last night, will that affect my temperature readings?

    If you drink a regular amount of alcohol each night, then your temperature is usually stable from night to night. However, if you consume more alcohol on one or two nights than your usual intake, this may cause a rise in temperature. The OvuSense App has been designed with an intelligent filtering system that excludes ‘spikes’ when calculating ovulation, but the 'spikes' in temperature related to alcohol tend to be lower than a fever and can sometimes cause an ovulation result. If you're unsure whether your results have been affected click on this link and fill out the support form.

    I'm using a hormonal contraceptive, or IUD, or stopped using one of these methods recently. Will that affect my temperature readings?

    Correct use of hormonal contraceptives should stop you from ovulating, so you will see no temperature rise associated with ovulation, and the OvuSense App is unlikely to provide an ovulation prediction and confirmation.

    You may still get a positive ovulation result with the OvuSense App if you're using an IUD, as these tend not to alter the hormonal pattern unless they also contain hormonal implants. In both cases as the IUD disrupts the lining of the uterus no implantation will take place, hence you cannot conceive and the result from your OvuSense App is therefore of no particular use in trying to conceive.

    However, it should be understood that hormonal and IUD contraceptive use is strongly discouraged while using OvuSense as the results will be invalidated.

    It takes the female body a varying amount of time to re-establish a normal hormone balance after you stop hormonal methods of contraception or have an IUD removed. The length of time it takes depends on the type of contraceptive and your individual body. As the hormone patterns start to normalize, regular menstruation will return and eventually so will ovulation. However, this may take up to 9 months with hormonal methods. During this time, OvuSense may be able to help by showing you whether you are ovulating, but the fertile window prediction may be of less use, as the cycle length and ovulation timing is likely to vary greatly, especially in the first three cycles.

    I sleep with a blanket, or my room is generally hot. Will that affect my readings?

    The OvuCore Sensor takes temperature measurements in the vagina every 5 minutes, and it is therefore not prone to external influences. The OvuFirst Sensor takes temperature measurements on the skin every 5 minutes, and it is therefore more prone to external influences. The key thing is the OvuSense App passes these temperature data through intelligent filtering systems that removes 'spikes' and determines the best representative temperature based on the whole night's recordings, so it is able to provide you meaningful and accurate results from night to night and it's these movements from one night to the next that are key in understanding if and when you're ovulating.

    Why is there a temperature difference or different ovulation result between my OvuSense App and my BBT (basal body temperature)? Which result is correct?

    How does it work?

    Long established in the clinical literature [1], the BBT method aims to help detect the date of ovulation in a cycle by taking the basal (lowest) temperature first thing on waking with an oral thermometer, and then charting the change in this daily temperature throughout the month to determine the date of ovulation. It can also be used if you have regular ovulation for predicting the fertile window in the next cycle. Because a rise in temperature is associated with the release of progesterone which occurs during ovulation, a predictable pattern emerges for most women which can help confirm ovulation took place over a number of cycles.

    How close will the results be compared to OvuSense?

    Even though the Basal Body Temperature (BBT) method uses temperature as a basis for confirming if ovulation took place, it relies on very different measuring technology from the patented protected system used by OvuSense. Oral thermometers only have an accuracy of around 0.1 degrees Celsius [a] so are not easily able to detect the 0.3 degree rise associated with ovulation with accuracy. Even if you type the values you get with your thermometer into a Fertility Tracker App they are likely to give a different ovulation result from OvuSense. You should also be aware that a vaginal temperature measured using the OvuCore Sensor is generally up to two degrees Celsius higher than temperature readings taken in the mouth, and higher still than external temperature readings such as those taken under the armpit or on the wrist. Lastly, OvuSense uses proprietary algorithms to detect ovulation, so it can produce very different results even with similar looking temperature curves.

    What are the benefits?

    BBT is a relatively cheap and easy way to track your temperatures and a number of apps are now available which combine the idea of a single oral temperature with automatic charting. It is more effective if combined with cervical mucus tracking.

    What are the drawbacks?

    Clinical studies show that 70% of women don’t ovulate in the middle of their cycle, and you can ovulate at a different time from cycle to cycle, even if your cycles are always the same length [2]. As a result because BBT relies on predicting the fertile window based on past cycle data, it's of little practical use if you don't ovulate at the same time each month. With or without an app to help, BBT is unable to help predict ovulation using the current cycle data. Again, even with an app, some users find the charting cumbersome and have difficulty taking a valid measurement each day. Studies assess accuracy for confirmation that ovulation took place at around 69%-83%[3].

    [1] Barrett JC Marshall J (1969); McCarthy and Rockette (1983) [2] Baird D, McConnaughey D (1995) Lenton EA, Landgren BM (1984a); Lenton EA, Landgren BM (1984b) [3] Freundl G, Godehardt E (2003); Barron M L Fehring R (2005); Bauman JE (1981)

    The patent protected OvuCore Sensor technology solves the issues caused by other methods by taking multiple overnight Core Body Temperature (CBT) measurements in the vagina using a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data, and then applies smoothing techniques to provide a clear curve and the truest representation of the action of progesterone on the ovaries. Using the OvuCore Sensor, your OvuSense App confirms the date of ovulation with 99% accuracy [b][d]. Unlike the other methods it is also able to predict ovulation in real time - the published literature shows it does this with an accuracy of 89% and a positive predictive value of 96% [c][d].

    The OvuFirst Sensor also solves some of these issues caused by other methods by taking multiple overnight skin temperature measurements using an identical set of components to our revolutionary patent protected OvuCore Sensor technology: it has a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data avoiding the problems caused by 'dropouts' experienced by other skin based monitors, and then applies smoothing techniques to provide the clearest possible curve provided by a skin measuring method. Using the OvuFirst Sensor, your OvuSense App confirms the ovulation window with suggested date of ovulation with over 90% accuracy [e].

    [a] The measuring resolution of a thermometer is the step between each temperature reading - a resolution of a normal 0.1 degree Celsius means a reading may be wrong by as much as 0.099 degrees Celsius, or in other words there are only 3 steps between a wrong and right ovulation result of 0.3 degrees Celsius rise, whereas 0.003 degrees resolution provides 100 steps.

    [b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

    [c] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

    [d] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    .

    Why is there a temperature difference or different ovulation result between my OvuSense App and my Skin Worn Device or Fertility Bracelet? Which result is correct?

    How do they work?

    A more modern application of the BBT method is to take several consecutive temperature measurements from the skin - either under the armpit, under the bra strap or on your wrist - at various intervals overnight, and then download and interpret these measurements on an app. Some of these devices record additional secondary parameters.

    How close will the results be compared to OvuSense?

    Even though Skin Worn/ Fertility Bracelet Devices (SW/ FB) use skin temperature as a basis for confirming if ovulation took place, they rely on very different measuring technology from the patented protected system used by OvuSense. They also use different algorithm methods, and you therefore shouldn't expect them to give you the same temperature or ovulation results. You should also be aware that a vaginal temperature measured using the OvuCore Sensor is generally up to two degrees Celsius higher than temperature readings taken in the mouth, and higher still than external temperature readings such as those taken under the armpit or on the wrist.

    What are the benefits?

    As with the BBT method, a skin worn device is a relatively easy way to track your temperatures and it's often more convenient. The devices help establish the pattern of temperature over time, and because of the volume of measurements, they are possibly a little more consistent in detecting ovulation than BBT with an oral thermometer.

    What are the drawbacks?

    Measuring temperature at the skin also has some negative aspects for devices that have not been optimised through side by side clinical testing with 'gold standard' methods. Firstly, the skin temperature tends to vary in opposition to core temperature changes associated with the release of progesterone, and secondly there is a high chance of 'dropouts' in the temperature signal because it's difficult to maintain contact between the skin and sensor consistently. Just as with BBT, these devices rely on predicting the fertile window based on past cycle data, so they are more suited to women with regular cycles.[2] They are unable to predict ovulation using current cycle data. There are no current papers assessing accuracy of the ability to confirm the date of ovulation, but published data for a wrist worn device shows a sensitivity of 81% (missing around 19% of ovulations) and an ability to confirm that ovulation took place within a fertile window (though not on which day) with a 'F score' of 0.78 which indicates 78% accuracy [3].

    [1] Barrett JC Marshall J (1969); McCarthey and Rockette (1983)
    [2] Baird D, McConnaughey D (1995); Lenton EA, Landgren BM (1984a); Lenton EA, Landgren BM (1984b)
    [3] Goodale BM, Shilaih M (2019)

    The patent protected OvuCore Sensor technology solves the issues caused by other methods by taking multiple overnight Core Body Temperature (CBT) measurements in the vagina using a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data, and then applies smoothing techniques to provide a clear curve and the truest representation of the action of progesterone on the ovaries. Using the OvuCore Sensor, your OvuSense App confirms the date of ovulation with 99% accuracy [b][d]. Unlike the other methods it is also able to predict ovulation in real time - the published literature shows it does this with an accuracy of 89% and a positive predictive value of 96% [c][d].

    The OvuFirst Sensor also solves some of these issues caused by other methods by taking multiple overnight skin temperature measurements using an identical set of components to our revolutionary patent protected OvuCore Sensor technology: it has a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data avoiding the problems caused by 'dropouts' experienced by other skin based monitors, and then applies smoothing techniques to provide the clearest possible curve provided by a skin measuring method. Using the OvuFirst Sensor, your OvuSense App confirms the ovulation window with suggested date of ovulation with over 90% accuracy [e].

    [a] The measuring resolution of a thermometer is the step between each temperature reading - a resolution of a normal 0.1 degree Celsius means a reading may be wrong by as much as 0.099 degrees Celsius, or in other words there are only 3 steps between a wrong and right ovulation result of 0.3 degrees Celsius rise, whereas 0.003 degrees resolution provides 100 steps.

    [b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

    [c] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

    [d] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    .

    Why is there a temperature difference or different ovulation result between my OvuSense and my Fertility Tracker App? Which result is correct?

    How do they work?

    Fertility Tracker Apps (FTAs) use the calendar based method of tracking. You input the dates of your period and the app will calculate your ovulation based on the assumption that you have 'middle of the month' ovulation. Some have more sophisticated algorithms which accept manually entered oral temperatures, or Ovulation Predictor Kit (Luteinizing Hormone) test results.

    How close will the results be compared to OvuSense?

    Even though Fertility Tracker Apps (FTAs) sometimes allow you to enter information other than just your period dates, they are not able to pinpoint the date of ovulation with useful accuracy because they are based on the assumption that all women have very regular cycles with ovulation that occurs in the 'middle of the month' Of all the methods for looking at your ovulation you need to know that FTAs are the least reliable, and you should really ignore the results they produce if you're struggling to conceive.

    What are the benefits?

    Fertility apps are convenient and a handy way of tracking the basic information in your cycle. They help you stay organised and often feature useful extra information to help with conception and pregnancy.

    What are the drawbacks?

    Clinical studies show that 70% of women don’t ovulate in the middle of their cycle, and you can ovulate at a different time from cycle to cycle, even if your cycles are always the same length [1]. A recent study into several fertility apps concluded 'as a result of the physiological variations of the menstrual cycle length and ovulation day, the fertile window cannot be predicted easily, and it has to be determined during the ongoing cycle. Therefore, to help couples wishing to conceive, apps based on data from previous cycles alone are not suitable to indicate the most fertile days' [2]. Another recent study concluded 'accuracy of ovulation prediction [using previous cycle data] was no better than 21%' [3]. Other studies have drawn similar conclusions [4].

    [1] Baird D, McConnaughey D (1995); Lenton EA, Landgren BM (1984a); Lenton EA, Landgren BM (1984b)
    [2] Freis A, Freundl-Schütt T (2018)
    [3] Johnson S, Marriott L (2018)
    [4] Freundl G, Godehardt E (2003); Moglia ML, Nguyen HV (2016); Wise LA, Hatch EE (2015)

    The patent protected OvuCore Sensor technology solves the issues caused by other methods by taking multiple overnight Core Body Temperature (CBT) measurements in the vagina using a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data, and then applies smoothing techniques to provide a clear curve and the truest representation of the action of progesterone on the ovaries. Using the OvuCore Sensor, your OvuSense App confirms the date of ovulation with 99% accuracy [b][d]. Unlike the other methods it is also able to predict ovulation in real time - the published literature shows it does this with an accuracy of 89% and a positive predictive value of 96% [c][d].

    The OvuFirst Sensor also solves some of these issues caused by other methods by taking multiple overnight skin temperature measurements using an identical set of components to our revolutionary patent protected OvuCore Sensor technology: it has a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data avoiding the problems caused by 'dropouts' experienced by other skin based monitors, and then applies smoothing techniques to provide the clearest possible curve provided by a skin measuring method. Using the OvuFirst Sensor, your OvuSense App confirms the ovulation window with suggested date of ovulation with over 90% accuracy [e].

    [a] The measuring resolution of a thermometer is the step between each temperature reading - a resolution of a normal 0.1 degree Celsius means a reading may be wrong by as much as 0.099 degrees Celsius, or in other words there are only 3 steps between a wrong and right ovulation result of 0.3 degrees Celsius rise, whereas 0.003 degrees resolution provides 100 steps.

    [b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

    [c] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

    [d] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    .

    Why is there a difference between my OvuSense result and my OPKs (Ovulation Predictor Kits) or Ovulation Prediction Monitor? Which is correct?

    How do they work?

    Ovulation Predictor Kits (OPKs) provide a positive test for Luteinizing Hormone (LH) using a urine test strip. Ovulation Prediction Monitors (OPMs) usually allow multiple ovulation predictor urine strip results to be combined to provide a monitoring picture of Luteinizing Hormone (LH) over a cycle. Some monitors use a urine strip that combines LH with E3G - a metabolite that allows assessment of the estradiol level.

    How close will the results be compared to OvuSense?

    Firstly, OPKs and OPMs are only able to provide a prediction of when ovulation may occur during the current cycle. They are not able to confirm you have ovulated, and because of the lack of confirmation they cannot be used to reliably predict your fertile window for the next cycle. When you're using the OvuCore Sensor your OvuSense App will also provide you with a prediction of when you are about to ovulate using the current cycle data. As this is based on the temperature pattern caused by the release of progesterone associated with ovulation, rather than luteizing hormone, it may well provide you with a different prediction. This is particularly true if you have an ovulatory issue such as PCOS which is known to interfere with OPK and OPM results. However, if your OvuSense App and an OPK or OPM predict the same day for ovulation then this can be very useful in confirming your hormone behaviour throughout the cycle.

    What are the benefits?

    LH peaks up to a day in advance of ovulation so OPKs and OPMs are helpful in providing a short term indication of when you should try and conceive based on your current cycle data. They work well at predicting ovulation for most women that have regular 'middle of the month' ovulation. The addition of E3G with OPMs helps provide a fertile window prediction and storing multiple results in the monitor helps with the convenience and monitoring over time compared with OPKs.

    What are the drawbacks?

    OPKs are known to give false positive results for women with PCOS and other ovulatory issues [1]. They sometimes also give false negative results, which can be based on the cutoff point of the test, or simply that the test is not optimised for the natural level of LH for the particular user. OPKs can only provide a snapshot at one point in time in your cycle, meaning you have to use a minimum of two tests a day over a 10-20 range in each cycle to monitor where you are in your cycle. The manufacturers make valid claims for 99% accuracy in detecting LH, but the accuracy estimates for correct advance prediction of ovulation are 70%-84% depending on the publication [2]. OPKs and OPMs are unable to confirm the date of ovulation or if you haven't ovulated. They are sometimes thought to be messy, impractical and the cost quickly adds up. Lastly, they cannot be used for clinical monitoring as they only provide a picture up to the point of ovulation and no understanding of what happens during ovulation itself, and the luteal phase.

    [1] McGovern PG, Myers ER (2004)
    [2] Irons DW, Singh M (1994); Lloyd R, Coulman CB (1989);

    The patent protected OvuCore Sensor technology solves the issues caused by other methods by taking multiple overnight Core Body Temperature (CBT) measurements in the vagina using a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data, and then applies smoothing techniques to provide a clear curve and the truest representation of the action of progesterone on the ovaries. Using the OvuCore Sensor, your OvuSense App confirms the date of ovulation with 99% accuracy [b][d]. Unlike the other methods it is also able to predict ovulation in real time - the published literature shows it does this with an accuracy of 89% and a positive predictive value of 96% [c][d].

    The OvuFirst Sensor also solves some of these issues caused by other methods by taking multiple overnight skin temperature measurements using an identical set of components to our revolutionary patent protected OvuCore Sensor technology: it has a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data avoiding the problems caused by 'dropouts' experienced by other skin based monitors, and then applies smoothing techniques to provide the clearest possible curve provided by a skin measuring method. Using the OvuFirst Sensor, your OvuSense App confirms the ovulation window with suggested date of ovulation with over 90% accuracy [e].

    [a] The measuring resolution of a thermometer is the step between each temperature reading - a resolution of a normal 0.1 degree Celsius means a reading may be wrong by as much as 0.099 degrees Celsius, or in other words there are only 3 steps between a wrong and right ovulation result of 0.3 degrees Celsius rise, whereas 0.003 degrees resolution provides 100 steps.

    [b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

    [c] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

    [d] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    .

    My OB/GYN or specialist says I ovulated on a different day to what OvuSense says. Why is that?

    Your OB/GYN or specialist may perform one or both of Serum Progesterone or Ultrasound tests. These are both discussed below

    Serum Progesterone

    How does it work?

    A serum blood progesterone measurement generally should be obtained approximately one week before the expected onset of the next menses [1] and in a 28 day cycle that's day 21 which is why the test is often called a '21-day progesterone'.

    How close will the results be compared to OvuSense?

    Serum progesterone is a standard method for confirming ovulation took place that is used by medical professionals throughout the world. It's reliable if your blood is drawn on the right day in your cycle, but it doesn't really provide an accurate day on which ovulation occurred, just a good assessment that it has occurred within a recent window of 5-10 days. If you OvuSense App confirmation fits within that window then it's a good sign but you shouldn't necessarily expect agreement between the results, and very importantly a negative serum progesterone result doesn't necessarily mean you haven't ovulated, particularly if OvuSense shows you have.

    What are the benefits?

    If timed correctly, a serum blood progestrone is an excellent way of confirming that you have definitely ovulatied in the current cycle. If it is used regularly in successive cycles it can help build up a picture of your ovulation which confirms home testing.

    What are the drawbacks?

    There is a real practical problem if you have irregular cycles or are in the 70% of women who ovulate at a different time in your cycle from the expected ‘norm’[2], or if you just don't have time to get in to have your blood drawn. Given that a false negative test can occur if the timing of your blood draw is out by even a day, a serum blood progesterone can also lead to the wrong conclusion – potentially setting you on a course of unnecessary treatment.

    [1] ASRM (2012) Diagnostic evaluation of the infertile female.; Fertility Assessment and Treatment of people with fertility problems.
    [2] Baird D, McConnaughey D (1995); Lenton EA, Landgren BM (1984a); Lenton EA, Landgren BM (1984b)

    Ultrasound

    How does it work?

    3-4 ultrasound 'folliculometry' scans per cycle is the suggested requirement of good cycle monitoring. Your clinician will usually be looking for a dominant follicle (the next one that is most likely to rupture resulting in ovulation) of 20mm or more in size in one of your ovaries. This measurement means that you are likely to ovulate in the next 24-48 hours.

    How close will the results be compared to OvuSense?

    Ultrasound 'folliculometry' is the accepted 'gold standard' assessment of ovulation as it's the only method which actually 'shows' ovulation about to take place or that it has taken place. It is really important to understand the prediction your OB/GYN or specialist gives you when saying you are going to ovulate having completed an ultrasound is based on an assessment of the size of your 'dominant follicle' which is assumed to be the same for all women. This means ovulation can occur in a window of 12-72 hours after your scan, or in fact may not occur at all, and the only way to confirm this is to go back for more scans in the same cycle. Ideally if you have a scan on one day and the follicle hasn't 'ruptured', and you have another scan on the next day and it has, then you know you ovulated in between - otherwise it can only be used as a guideline for the ovulation window.

    What are the benefits?

    If timed correctly, ultrasound 'folliculmetry' is the accepted gold standard for confirming the likelihood of ovulation in a cycle [1]. It is also essential in assessing the growth and number of follicles, particularly during stimulation of the ovaries, and vital in diagnosis of ovarian issues such as PCOS.

    What are the drawbacks?

    Ultrasound ‘folliculometry’ is not always a good predictor of ovulation, and this isn’t surprising given that it assumes that all women of whatever size and shape, or hormonal make-up will have identically sized follicles just before ovulation occurs. Dominant follicle size can vary greatly [2]. Katiyar et al. (2018) reported on the ability of ultrasound folliculometry to predict ovulation in 100 infertile women, concluding folliculometry predicted ovulation with an accuracy of 86% with a specificity of 58.6% and a sensitivity of 98.6% [3]. Also, because a scan is a snapshot at one point in time in your cycle, timing the scan correctly is essential, and a number are needed in cycles where the timing of ovulation needs to be known. This is often impractical for the patient and the clinic.

    [1] ASRM (2012) Diagnostic evaluation of the infertile female.; NICE (2004). Fertility Assessment and Treatment of people with fertility problems.
    [2] Vlaisavljević V, Došen M (2007)
    [3] Katiyar S, Arya S (2018)

    How OvuSense compares

    The patent protected OvuCore Sensor technology solves the issues caused by other methods by taking multiple overnight Core Body Temperature (CBT) measurements in the vagina using a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data, and then applies smoothing techniques to provide a clear curve and the truest representation of the action of progesterone on the ovaries. Using the OvuCore Sensor, your OvuSense App confirms the date of ovulation with 99% accuracy [b][d]. Unlike the other methods it is also able to predict ovulation in real time - the published literature shows it does this with an accuracy of 89% and a positive predictive value of 96% [c][d].

    The OvuFirst Sensor also solves some of these issues caused by other methods by taking multiple overnight skin temperature measurements using an identical set of components to our revolutionary patent protected OvuCore Sensor technology: it has a thermistor with a resolution of 0.003 degrees Celsius [a], the OvuSense algorithm intelligently filters the data avoiding the problems caused by 'dropouts' experienced by other skin based monitors, and then applies smoothing techniques to provide the clearest possible curve provided by a skin measuring method. Using the OvuFirst Sensor, your OvuSense App confirms the ovulation window with suggested date of ovulation with over 90% accuracy [e].

    [a] The measuring resolution of a thermometer is the step between each temperature reading - a resolution of a normal 0.1 degree Celsius means a reading may be wrong by as much as 0.099 degrees Celsius, or in other words there are only 3 steps between a wrong and right ovulation result of 0.3 degrees Celsius rise, whereas 0.003 degrees resolution provides 100 steps.

    [b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

    [c] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

    [d] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    .

    Why does OvuSense seem to take so long to confirm, like up to 2-5 days sometimes?

    The OvuSense App processes the data you download from your sensor to provide the most accurate picture of your cycle it can. Particularly in more disturbed cycles, it's important to know whether the rise in temperature has been sustained. Only then is it clear that ovulation has taken place. So other temperature based methods generally confirm earlier but with around 82%-86% accuracy and they can't reliably tell you the day on which ovulation occurred [2]. OvuSense waits the 2-5 days to confirm ovulation ensuring the highest possible accuracy - 99% with the OvuCore Sensor [3] - and a full analysis of the cycle pattern either side of ovulation in order to determine if you have an ovulatory issue using OvuSense Pro [4]. The OvuFirst Sensor provides an accuracy of over 90% for the ovulation window with the suggested day of ovulation. [5]

    [1] Barrett JC Marshall J (1969); McCarthy and Rockette (1983)

    [2] Freundl G, Godehardt E (2003); Barron M L Fehring R (2005); Bauman JE (1981)

    [3] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

    the atypical cycle patterns which led to the development of the OvuSense Pro product:
    [4] Hurst BS, Karoshi M (2020) Atypical Core Body Temperature patterns and the wider implications for conditions related to pregnancy, infertility, and miscarriage risk P-833 American Society for Reproductive Medicine 76th Annual conference. Poster; Fertility and Sterility - September 2020 Volume 114, Issue 3, Supplement, Pages e446–e447; Hurst BS, Pirrie A (2019) Atypical vaginal temperature patterns may identify subtle not yet recognised causes of infertility P-345 American Society for Reproductive Medicine 75th Annual conference., Fertility and Sterility - September 2019 Volume 112, Issue 3, Supplement, Pages e244–e245

    [5] Internal Fertility Focus side by side study of OvuFirst and OvuCore Sensors (2021), documented as a class II medical device in the notified body reviewed CE Certificate Technical File.

    Can my medication affect OvuSense results?

    The effect of medications on progesterone and therefore on temperature levels in the cycle is predictable, and the likelihood of interference with results from fertility or cycle related medications is greatly reduced as they are generally not taken in the cycle around the time at which ovulation is expected. Most fertility related medications are targeted at creating a positive effect on the process of ovulation and/ or cycle regulation and therefore in fact make temperature less likely to fluctuate in a way we don't expect. OvuSense can also be used to track those positive effects. The exception is progesterone supplementation which may be taken around the time of ovulation, and if this is the case your OvuSense App may show the resulting progesterone medication related rise in temperature as ovulation. In other words it may produce a false positive result. If you change any medication regime from one cycle to the next, for instance thyroid medication, this may also affect your temperature pattern from one cycle to the next but as OvuSense is designed to look for relative changes in temperature within the cycle this is unlikely to change the prediction or confirmation of ovulation. Ask your OB/GYN or specialist if you are unsure as to how the timing and dose of any of your medications may affect your temperature. Your OB/GYN or specialist may also be interested in learning more about how OvuSense® Pro can help them monitor your medication. Read more about OvuSense® Pro by clicking here

    Can my IUI or IVF treatment affect my results, what about the hCG 'trigger shot'?

    OvuSense can still be used while you are undergoing IUI or IVF treatment and may provide valuable extra information to your clinician including when to time insemination or embryo transfer. IUI treatment may include an hCG 'trigger shot' to induce ovulation. Experience over a number of cycles with OvuSense users shows that your OvuSense App will often still confirm ovulation but it may do so 1-2 days after the day on which your clinician tells you that ovulation should take place. This is because the temperature curve resulting from the hCG trigger shot is usually a little slower than the one produced by 'natural ovulation'. When undergoing IVF, your hormonal profile is likely to be completely different from your natural unmedicated profile so you should not expect OvuSense to produce accurate ovulation prediction or confirmation. However, the cycle pattern produced by OvuSense may still prove useful to your clinician.

    Is OvuSense a diagnostic device?

    NO. OvuSense cannot be used to directly diagnose ovulatory or other issues. However, the results from your OvuSense App and OvuSense® Pro can be used by an OB/GYN or specialist to prompt for further testing, so OvuSense is an AID to diagnosis but does not provide diagnostic results itself.

    The complete detail of your charts, and events such as medication dosage and timing logged in the OvuSense App can be shared with your OB/GYN or specialist through the OvuSense® Pro portal. In addition, OvuSense Pro provides automatic recognition of the range of aytpical cycle patterns including unique patterns derived from OvuSense discussed in recent clinical studies. These cycle patterns can aid diagnosis of ovulatory issues, miscarriage risk and possibly pregnancy complications. The Pro system requires a separate subscription and can be accessed via any web browser on a computer or mobile device. Read more about OvuSense® Pro by clicking here

    Do I need to be connected to the internet to use my OvuSense App?

    No, your mobile device does not need to connect to internet for it to work and connect your Sensor. The OvuSense App will work offline for up to 30 days and you will receive warnings when you need to connect again to the internet to back up your data

    Beyond day 30 all your previous data will be retained by the OvuSense App but you will no longer be able to connect your OvuSense Sensor until you have connected to the internet again.

    I have no access to the internet, can I still use my OvuSense App?

    Yes, you can use the OvuSense App for up to 30 days without internet access. See Q: Do I need to be connected to the internet to use my OvuSense App?

    I work shift hours, which means I have irregular sleep patterns, can I still use OvuSense?

    You can use OvuSense if you work shifts as long as you have a regular pattern of sleep during a week or more. The most important thing is to wear the OvuSense sensor for a minimum of 6 hours while you are at rest.

OvuCore Sensor questions

    How far should I insert the OvuCore Sensor?

    Hold the OvuCore Sensor where the tail joins the main body. Aim toward the small of your back, and push it up. Once your OvuCore Sensor is in place, you shouldn’t be able to feel it. If it's painful to sit down or walk around then the OvuCore Sensor isn't far enough up the vagina. Insert your finger inside the vagina until you feel the OvuCore Sensor. Push slightly, then do another walking test. The OvuCore Sensor will never get stuck or lost inside you, there's nowhere for it to go.

    My OvuCore Sensor keeps falling out. Is there anything I can do to try and keep it in?

    Perhaps your OvuCore Sensor isn’t in place properly. Insert your finger inside the vagina until you feel the OvuCore Sensor. Push slightly and see if it holds in place. If you are still having problems please contact us by clicking on this link and filling out the support form.

    I’m spotting with some blood, should I use my OvuCore Sensor?

    No, you should not use the OvuCore Sensor when you are bleeding or spotting.

    What should I clean the OvuCore Sensor with?

    The OvuCore Sensor is designed with medical grade materials that prevent growth of bacteria. The OvuCore Sensor should be cleaned on first use, and before or after each use by washing it with unscented and fragrance free soap in warm water. DO NOT clean the OvuCore Sensor in disinfectants or alcohol, or with antibacterial or disinfectant wipes, or 'intimate wash' soap, or with soaps that contain additives and/ or essential oils.

    Should I take the OvuCore Sensor out to have sex?

    It is essential to remove the OvuCore Sensor before sex. We recommend that the OvuCore Sensor is reinserted after sex, to increase the amount of data collected. If you decide to continue using the Sensor after sex, remember to wash it before reinserting it. The OvuCore Sensor is designed to discard temperature data which are not within the normal body range so any data collected when not in use will be removed.

    Should I take the OvuCore Sensor out to go to the bathroom at night?

    You do not need to remove the OvuCore Sensor when going to the bathroom. However, some users do have the problem that it can fall out while sitting on the toilet. We therefore recommend you hold the tail just in case it falls out. Or if you prefer simply remove the OvuCore Sensor before you go to the bathroom and reinsert after. Remember to wash it before reinserting it. The OvuCore Sensor is designed to discard temperature data which are not within the normal body range so any data collected when not in use will be removed.

OvuFirst Sensor questions

    How do I wear the OvuFirst Sensor?

    The OvuFirst Sensor should be worn on your skin in one of three locations. We recommend you wear it under your arm (as far into the armpit as is comfortable) using one of our specially designed armbands that you can choose free of charge during the checkout process, as that has been shown to produce the most accurate and consistent results. However, you can also wear it on the underside of your wrist using our wristband. Alternatively, you can wear it under a bra strap. We strongly recommend that you do not move your OvuFirst Sensor from one of these 'locations' to another during a cycle as it is likely to provide inaccurate results. If you do want to change 'location' for the OvuFirst Sensor on your skin, wait until your next cycle starts and then switch.

    How do I work out which size armband/ wristband to use with the OvuFirst sensor?

    The OvuFirst sensor comes with the choice of one free specially designed armband or a free wristband. There are three sizes of armband and a 'one-size-fits-all' wristband. If you want to wear it on your arm, please measure around the widest section of the upper arm located above the elbow. OvuFirst is to be worn directly on the skin so make sure you are measuring your arm on the skin without clothes over the top for an accurate size. Use a fabric tape measure so that you can get around your arm. If you don’t have one, you can use a piece of string and then lay the string out length-wise against a ruler to obtain the measurement

    Size Guide
    • Wristband (One Size)
    • Armband Size D: 18cm - 23cm (7in - 9in)
    • Armband Size F: 23cm - 34cm (9in - 13.5in)
    • Armband Size G: 34cm - 40cm (13.5in - 16in)
    How should I wash my OvuFirst armband or wristband?

    We recommend you wash or OvuFirst armband or wristband in a cold wash, and that you lay flat or hang on a line to dry. Don't put your armband or wristband in a dryer

    My OvuFirst Sensor keeps falling out of the armband/ wristband. Is there anything I can do to try and keep it in?

    It's possible that you have the wrong size of armband or wristband. If this problem happens for more than 3 consecutive nights please contact us by clicking on this link and filling out the support form.

    My OvuFirst Sensor is uncomfortable to wear at night. Is there anything I can do to make it more comfortable to wear?

    It's possible that you have the wrong size of armband or wristband. If this problem happens for more than 3 consecutive nights please contact us by clicking on this link and filling out the support form.

    I’m spotting with blood or on my period, should I use my OvuFirst Sensor?

    Yes, unlike the OvuCore Sensor you can continue you use the OvuFirst Sensor when you are bleeding or spotting. The results during this time can be helpful in providing a better understanding of your cycle.

    What should I clean the OvuFirst Sensor with?

    The OvuFirst Sensor is designed with medical grade materials that prevent growth of bacteria. The OvuFirst Sensor should be cleaned on first use, and before or after each use by washing it with unscented and fragrance free soap in warm water. DO NOT clean the OvuCore Sensor in disinfectants or alcohol, or with antibacterial or disinfectant wipes, or 'intimate wash' soap, or with soaps that contain additives and/ or essential oils.

    Should I take the OvuFirst Sensor off to have sex?

    There is no requirement to remove the OvuFirst Sensor before sex, though you may find it more comfortable to do so. If you do take it off we recommend that the OvuFirst Sensor is put on again after sex to increase the amount of data collected. The OvuFirst Sensor is designed to discard temperature data which are not within the normal body range so any data collected when not in use will be removed.

    Should I take the OvuFirst Sensor off if I go to the bathroom at night?

    You do not need to remove the OvuFirst Sensor when going to the bathroom. The OvuFirst Sensor is designed to discard temperature data which are not within the normal body range so any data collected when not in use will be removed.

Order and Delivery

    Where can I buy OvuSense?

    You can purchase OvuSense directly from the store on our website: www.ovusense.com/store.

    Before you buy OvuSense it's best to download the free OvuSense App first and set it up with a user name. To download the OvuSense App click one of these buttons:

Payment

    How can I cancel my monthly payments?

    To cancel your monthly payments you will need to log in to your PayPal account and do the following:

    1) click 'Profile' in the top right corner

    2) a drop-down menu appears; click 'Profile and Settings'

    3) click 'My Money' in the left-hand panel

    4) click 'Update' to the right of 'My pre-approved payments'

    5) click 'Fertility Focus Ltd' or 'Fertility Focus Inc'

    6) click 'Cancel'

    7) a pop-up window appears; click 'Cancel Profile' You can cancel your monthly payment at any time before the next payment is due.

    If you wish to use OvuSense at a later date you can re-subscribe at any time, please visit our website www.ovusense.com, and purchase a new subscription. Your data will be stored on our database for an indefinite period according to the terms and conditions agreed when you signed up.

    What will happen to my data if I stop for a month or so, or all together?

    If you decide to stop your OvuSense subscription then no data can be collected until you re-subscribe. If you wish to use OvuSense at a later date you can re-subscribe at any time, please visit our website www.ovusense.com, and purchase a new subscription. Your data will be stored on our database for an indefinite period according to the terms and conditions agreed when you signed up.

    I’ve lost my sensor. Can I buy a new one?

    Yes, you can purchase a new sensor from our website by requesting support here request a new sensor. Your new sensor will need to be registered to your OvuSense App account by clicking on 'Sensor > Register a new Sensor' in the OvuSense App.

    Can I share my sensor with a friend and can she carry on with subscriptions to save money?

    As a regulated medical device, the sensor is strictly for your personal use only. Sharing it with others may present a hygiene risk. Each sensor is uniquely registered to your OvuSense App account, so your friend will need to set up her own account and purchase her own sensor.

    Are there any guarantees with OvuSense, or money back offers, if I am not successful in getting pregnant?

    At OvuSense, we never promise ovulation or pregnancy. OvuSense offers you extremely accurate information about your cycles that you can ‘do’ something with, even if that information isn’t great news. OvuSense is the only fertility monitor that will tell you if you have, and have NOT, ovulated each cycle . Finding out you haven’t ovulated consistently isn’t great news and that’s why we created the ‘OvuSense Ovulation Promise’. If you use OvuSense for 90 days in a row and ovulation is not detected, we will offer you the option to switch to an alternate sensor, or a full refund to help you seek clinical advice and treatment if that's needed. Click here to find out more.

The OvuSense App and OvuSense Pro and data security

    I’m worried about my data getting leaked. How is it protected?

    At OvuSense data security is the highest priority, your data is stored in an encrypted format in the cloud meaning it secure and cannot be deciphered. The cloud database we use complies with strict regulatory guidelines which includes security management to the ISO 27001 standard and personal data protection to the ISO 27018 standard.

    Who can see my data besides me?

    The data can only be seen by the users you have chosen to share your data with and the OvuSense Technical Support team. If you contact us with a question, our support team may view your data if doing so is necessary to solve your problem.

    We keep your Personal Information confidential and generally do not disclose it. Please note that we would never sell your Personal Information to any third parties, nor would we share your information to social networks or other public places unless we have received prior consent from you.

Subscriptions

    Why do I need a subscription?

    A subscription is required to download and process your data from the sensor. While a subscription is valid you can continue to press ‘Connect’ and download data to your OvuSense App. You can cancel your OvuSense subscription at any time

    What happens if I cancel my subscription?

    After you cancel your subscription, it will remain valid until the end of the current 30 day billing period. At that point, you can continue to connect to your OvuSense Sensor for an additional 7 days ‘grace period’. Once cancelled, you cannot reactivate your old subscription. However, you can simply purchase a new subscription from ovusense.com anytime you like and pick up using OvuSense where you left off. If you purchase a new subscription within the ‘grace period’ you will not have any gaps on your graph.

    How do I cancel my subscription?

    1) Login to the PayPal account you used or created when you ordered your OvuSense subscription

    Login to your PayPal account

    Login to your PayPal account

    2) Click on the settings wheel in the top right of the screen

    Click on the settings wheel

    3) Click on the Payments Tab

    Click on the Payments Tab

    4) Click on the Pre-approved Payments option

    Click on the Pre-approved Payments option

    5) Click on the recurring subscription for OvuSense in the list

    Click on the recurring subscription for OvuSense in the list

    6) Click on Cancel to cancel your OvuSense subscription

    Click on Cancel to cancel your OvuSense subscription

Tracking your cycle in real time

Cycle 1

Start using OvuSense immediately by downloading data from your sensor each morning to the OvuSense App. Your temperature is tracked in real time.

After a few days, if you're using the OvuCore sensor, OvuSense can predict the onset of your ovulation without having to wait until the next cycle or rely on historic data.

Three days after you ovulate, OvuSense confirms the exact ovulation date. You can also continue monitoring your temperature to see what's happening with your progesterone levels during your luteal phase.

Real time cycle tracking app - Cycle 2
Real time cycle tracking app - Cycle 1

Cycle 2

Stop using the OvuCore Sensor during your period, recommencing use immediately after it ends. OvuSense will then predict the 8 days you are most likely to conceive in this cycle. If you're using the OvuFirst Sensor you can keep tracking throughout your period.

OvuSense updates the information it provides in real time during the cycle, replacing the 8 day 'long range' window with a 'short range' 4 day ovulation window.

Scroll on the OvuSense App to compare your ovulation dates and your cycle pattern. Real time data can be shared with your partner and/or doctor through the OvuSense Pro clinician portal.

Read about women already using OvuSense

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