Can Fertility "Apps" Predict Ovulation?
If looking to conceive then tracking your ovulation and knowing your 'fertile window' is key
…but don't rely solely on your fertility app!
Depending upon which app you use, it may claim to predict your exact day of ovulation but unfortunately this is next to impossible from an App alone (sorry FAB! - Fertility Awareness Based Apps).
These calendar-based apps can be great and very useful as they allow you to track and better understand your cycles and 'predict' the most fertile days of the cycle based on a few, averaged data points of previous cycles.
They identify a pattern (are your cycles regular or irregular?), give you information on your weight fluctuations, moods and a lot more. However, this retrospective method looking backwards is viewed as inadequately reliable as a result of the known variability of the cycle length and ovulation day from month to month. When predicting ovulation they assume that you are ovulating 14 days before your next period is due (based upon a typical textbook 28 day cycle) or basing their assumption on your previous cycle length. Not entirely accurate as a prediction method.
New research out of Nature Digital Medicine found that only 13% of women actually have menstrual cycles that are 28 days in length, so for this reason we believe women should understand their own cycle characteristics rather than relying on a standardised cycle length.(1)
The Research on "Fertility Apps"
Researchers from University College London and Natural Cycles Fertility App sought out to analyse key characteristics, including associations with age, BMI and body temperature of over 600,000 menstrual cycles and data from nearly 125,000 women in Sweden, the US and the UK using the company’s contraceptive app between September 2016 and February this year. (1)
“For the first time, our study shows that few women have the textbook 28 day [sic] cycle, with some experiencing very short or very long cycles,” said Professor Joyce Harper, from the UCL Institute for Women’s Health
This research shows that we cannot assume all women ovulate on day 14. Ovulation can vary from day 10 to day 20 of your cycle depending upon the cycle length. Therefore, the timing of the fertile window is highly variable and fertility 'apps' based solely on data from previous cycles alone are not suitable to indicate the most fertile days and should not be used to predict your ovulation.
'We studied all women who used the app. In order to identify the fertile period, it is important to track other measures such as basal body temperature as cycle dates alone are not informative,” Professor Harper explained
So how do I predict my ovulation?
Ovulation Predictor Kits (OPK's)
Ovulation predictor kits are checking for one thing - your Leutenizing hormone or 'LH' surge that is responsible for and precedes ovulation.
Why is this important? It's important because when trying to conceive, sexual intercourse needs to be timed carefully so sperm meets egg! An egg can survive for 12-24 hours post ovulation (sperm can live for 5 days) and so we want sperm to be there ready and waiting as soon as the egg is released. This means that your fertile window is 6 days, the day of ovulation and 5 days prior to this.
Note: OPKs work for many women, however not for all. On average, the LH surge the OPKs detect occurs about 24 hours before ovulation, but the timing of the surge may vary from about 16 to up to 48 hours.
Note: OPKs work for many women, however not for all. On average, the LH surge the OPKs detect occurs about 24 hours before ovulation, but the timing of the surge may vary from about 16 to up to 48 hours.
The Research on OPKs
A 2015 Cochrane review by Manders et al examined randomised controlled trial (RCT) evidence for the effectiveness of timed intercourse using both OPKs and other fertility awareness methods on the outcomes of live birth, pregnancy and adverse events, including stress. (2) They found that timed intercourse using OPKs may increase pregnancy rates compared with intercourse without ovulation prediction, with no difference in stress. Their research showed that OPKs do not directly pinpoint a peak fertility day and may need multiple pregnancy attempts within the appropriate timeframe during a woman’s menstrual cycle but that they are pretty accurate at predicting ovulation and the fertile window. (3)(4) They are useful in that they increase fertility awareness about when ovulation should occur during the woman’s cycle and may alert to potential menstrual cycle abnormalities.
In summary, three RCTs showed evidence that ovulation predictor kits may increase pregnancy rates by about 40%. (5) One RCT that measured stress and anxiety from using ovulation predictor kits found basically no increase in stress or anxiety from using ovulation predictor kits - good news there! Trying to conceive can be stressful enough, we don't want to add any more.
Tip: The kits can be bought over the counter. No prescription needed.
How do Ovulation Kits actually work?
This is one of the most common questions of women planning for a baby and dealing with fertility isues.
An ovulation kit tests your urine sample to detect a surge in LH (luteinizing hormone) levels. While the LH is always present in your urine, it increases 24 — 36 hours before ovulation. These tests help you find out those days that are best to have sexual intercourse when trying to conceive. One or two days before ovulation, your LH may surge up to five times the amount.
The LH surge happens 24 — 36 hours before ovulation
This time is your most fertile window. Having intercourse on those particular days increases your chance of pregnancy.
What if the kit is not picking up any LH surge?
You may be testing at inappropriate timings (best to test in the mid afternoon)
You may be ovulating but missing the LH surge, testing either too early or too late (consider checking for the LH surges twice per day in this case). Surges can sometimes be short <10 hours)
Ovulation disorder
Possible causes of ovulation problems include:
anxiety (not to be underestimated)
polycystic ovary syndrome (PCOS)
hypothalamus not secreting gonadotropin-releasing hormone
ovaries producing too little estrogen
adrenal glands overproducing male hormones, for example testosterone
pituitary gland producing too little LH or follicle-stimulating hormones
pituitary gland producing too much prolactin
blood sugar/diabetes
strenuous exercise
health issues, including cysts, tumors, or other masses
obesity or excessive weight loss
drugs (estrogens and progestins)
Depending only on OPKs is not always the most reliable way to increase your odds of getting pregnant. If having problems picking up on your exact timing of ovulation seek a professional opinion.
Basal Body Temperature (BBT) Monitoring
Get your pen and paper out! Monitoring your rise in temperature is another way to track ovulation and is relatively easy to do.
Basal body temperature (BBT) is the lowest body temperature taken during rest (usually during sleep). It is usually estimated by a temperature measurement immediately after waking and before getting out of bed. Ovulation causes a slight increase in body temperature of about 0.1-0.2 degrees due to the rise in the hormone progesterone. You can record your daily basal body temperature on a temperature tracker chart (above) or fertility apps such as Natural Cycles.
Identifying Ovulation
With basal body temperature charting, you're looking for an overall pattern, as opposed to a temperature spike here or there. Your temperature may rise and fall throughout your cycle, but you should notice a drop in temperature right before ovulation and then an increase for several days after (see chart below). After you see at least three higher-than-average temperatures in a row, you can most likely say that ovulation occurred on the day before the first high temperature.
Basal Body Temperature Charting
Tip: Ideally, you need a thermometer that is accurate to 1/10th (98.6) of a degree if you measure in Fahrenheit or 1/100th (37.00) of a degree in Celsius
Before ovulation, a woman's BBT averages between 36.1°C (97°F) and 36.4°C (97.5°F). After ovulation, it rises to 36.4°C (97.6°F) to 37°C (98.6°F).
Cervical Mucus
If you are part of the TTC 'Trying to Conceive Community', then you may already be well aware of the changes that occur with cervical mucus during your cycle. Cervical mucus plays a fundamental role in conception as it nourishes and protects the sperm during the long and arduous journey it makes through the female reproductive tract. The amount and consistency of the mucus fluctuates and is influenced by hormonal changes throughout the cycle. Approaching ovulation, oestrogen peaks and more cervical mucus is produced. We call this 'fertile quality mucus'. It has also been called egg white cervical mucus (EWCM), as it is clear and stretchy, similar to the consistency of egg whites, and is the ideal protective medium for sperm. By assessing your cervical mucus daily you will be able to identify any changes and use this as a sign that ovulation is happening.
Other Sings and Symptoms of Ovulation:
Heightened sense of smell
Breast tenderness and nipple sensitivity
Mild pelvic pain (usually on one side)
Libido change (increase in sex drive)
Changes in cervix - becomes softer and more open
Take Home:
When using apps to help determine your fertile window, make sure you are using ones that take into account your cycle length in addition to basal body temperature and cervical mucus changes. Natural Cycles is an FDA approved Fertility App and one which I recommend. OPK's are useful and are recommended once used correctly.
A little note:
Infertility can take a hefty emotional and financial toll on couples and the longer it takes to conceive, the bigger the impact. Before an infertility diagnosis or spending money on treatments, be sure get a semen analysis and chart female fertility characteristics to rule out the possibility that simple mis-timed intercourse is standing in the way of conception.
Having said this, remember that when you are trying to conceive - time is of the essence. If you are under the age of 35 and have been trying for 12 months without success it is recommended to seek the support of your fertility specialist at the 12 month mark. If over 35 and have been trying for 6 months but unsuccessfully, visit your fertility specialist after 6 months. If over 45 it is recommended to seek support much sooner, after 3 months or even immediately to give yourself the best chances.
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References
1. Bull, J.R., Rowland, S.P., Scherwitzl, E.B. et al. Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. npj Digit. Med. 2, 83 (2019) doi:10.1038/s41746-019-0152-7
2. Manders M, McLindon L, Schulze B, et al. Timed intercourse for couples trying to conceive. Cochrane Database Syst Rev2015;2015.doi:10.1002/14651858.CD011345.pub2
3. Su H-W, Yi Y-C, Wei T-Y, et al. Detection of ovulation, a review of currently available methods. Bioeng Transl Med 2017;2(3):238–46.doi:10.1002/btm2.10058
4. Eichner SF, Timpe EM. Urinary-based ovulation and pregnancy: point-of-care testing. Ann Pharmacother 2004;38:325–31.doi:10.1345/aph.1D210
5. Yeh PT, Kennedy CE, Van der Poel S, et al. Should home-based ovulation predictor kits be offered as an additional approach for fertility management for women and couples desiring pregnancy? A systematic review and meta-analysis, BMJ Global Health 2019;4:e001403.