Ovulation & Fertile Window
How to Choose the Best Ovulation Tracker for You
Preparing for a healthy pregnancy
An Ovulation Tracker Selection Guide by Ovaterra Scientific Team
When you decide that it’s time to start trying for a baby, one of the first things you should do is to track your ovulation. (The other is to start taking high-quality prenatal vitamins to fill in common prenatal nutritional gaps.) Ovulation trackers – also called ovulation predictor kits (OPKs) or ovulation tests – help you know when you ovulate and allow you to time the intercourse to increase your chances.
There are many to choose from, and your friend’s best ovulation tracker may not be the best ovulation tracker for you – because we all have different schedules, different preferences, and most importantly, different bodies. In this guide, we’ll cover the 3 major types of ovulation trackers and help you choose the right one for you. You can jump to any section:
- Why you should track ovulation
- DIY methods of ovulation tracking
- BBT-based ovulation tracking and what we recommend
- Hormone-based ovulation tracking and what we recommend
- Cervical mucus-based ovulation tracking and what we recommend
- How to choose the right ovulation tracker for you
Why is it important to track ovulation?
Pregnancy can happen on just 4-5 days each cycle. It’s because the egg can survive for only about 24 hours after ovulation. Sperm, on the other hand, can survive for 4-5 days in the female reproductive tract. So, when you have an intercourse 4-5 days before your ovulation, the sperm can stick around until the egg is released from the ovary – extending the “fertile window” to about 4-5 days.
This relatively short window makes it important to track ovulation for couples trying to conceive. If you know your fertile period and time your intercourse well, you have a good chance of getting pregnant, while having sex any other time – the 23 or so days left in your cycle – usually doesn’t result in a pregnancy.
How do you track ovulation and know when you are fertile?
There are several DIY ways to be more in tune with the signs of your fertile period and ovulation. Women with very regular periods can often estimate the day of ovulation and count backward to guess when they are fertile. Some can tell they are ovulating from physical symptoms like cramps, changes in the texture of cervical mucus and a rise in basal body temperature
These are not folk medicine; all these methods have a scientific basis. However, they are not always reliable, with one study finding that 85% of women who use these methods misidentify their fertile window, while believing that they are timing their intercourse correctly. Even for women who experience clear signs of ovulation, there is a learning curve. It can be a few months of trial and error before you nail it.
What is an ovulation tracker? And what types of ovulation trackers are there?
Ovulation trackers are the tests and devices that make it easier and more reliable to track ovulation, as well as identify the fertile window. There are several types, with different capabilities, using different scientific methods.
1. Ovulation tracking that use cervical mucus method
Why cervical mucus method works to track ovulation
Cervical mucus, also called cervical fluid, is the fluid that is released by the cervix into the vagina. Driven by hormonal changes, the composition of the cervical mucus changes depending on what phase of your menstrual cycle you are in. In most of your menstrual cycle, cervical mucus prevents sperm from entering the uterus. When you are close to ovulation, cervical mucus becomes more hospitable toward sperm, helping it move into the uterus and beyond for fertilization. By paying attention to the changes in the characteristics of your cervical mucus, you can detect your fertile window.
What it’s like to use cervical mucus method of ovulation tracking
At the beginning of your cycle, your cervical mucus is either dry or sticky. As you move toward ovulation, it becomes creamy, then slippery/watery. Typically, the slippery cervical mucus resembling raw egg whites is a sign of your fertile window, just before ovulation. This is when you’d plan your intercourse.
Traditional method involves inserting your clean finger in your vagina to take a sample and examining it for color and texture. Alternatively, you can look at the discharge on your underwear or on the toilet paper you used to wipe – though these are less reliable than the direct finger method. Charting the observations each day helps you spot the pattern better.
Pros & cons of using cervical mucus to track ovulation
Though the scientific research into cervical fluid and menstrual cycles started in the 1940s, women have been using this method for much longer to either facilitate pregnancy or avoid one. It can be an effective method of ovulation tracking: A study, though small, found that 90% of healthy couples who used a cervical mucus-based tracking were able to get pregnant within 3 months.
The DIY method is free. With this non-invasive, quick method, you can also detect a wider window of your fertility than just the 12-36 hours around ovulation – a major plus over other traditional methods of ovulation tracking.
Some of the downsides of cervical mucus methods are similar to those of the other traditional ovulation tracking methods.
- Learning curve: Most women need several cycles to learn how to differentiate the types of cervical mucus and understand their pattern.
- Subjectivity: Like other traditional methods, cervical mucus-based fertility tracking is subjective. Some women have great success, but not everyone can easily identify their fertile window, especially when their cervical mucus doesn’t follow a clear pattern (although this can be a useful sign that something isn’t working right, and you should talk to your doctor).
- The “ick” factor: Let’s be honest – getting up close and personal with your cervical mucus isn’t for everyone.
Next-gen cervical mucus ovulation trackers
A more advanced, cervical mucus-based ovulation tracker is now available on the market, and our scientific team recommends the device: kegg. By measuring the changes in the cervical mucus through electric impedance and using a learning algorithm to analyze the results, kegg takes the learning curve and subjectivity out.
Because cervical mucus shifts in composition days before ovulation, kegg is able to give you a 5-day fertile window to time your intercourse – a much less anxious experience than rushing on the day of ovulation. A bonus feature: You can use kegg as a Kegel ball for pelvic floor exercise, and doing so also helps the device measure your mucus. That said, at the time of writing, kegg isn’t recommended for women with cycles shorter than 21 days or longer than 40 days.
2. Ovulation tracking with BBT method
Why BBT method works
BBT – or basal body temperature – method of ovulation tracking is based on the cyclical changes in the core body temperature. When you ovulate, the ovarian follicle that contained the just-ovulated egg becomes a structure called corpus luteum. It produces progesterone, a reproductive hormone that thickens the lining of the uterus to prepare for a possible pregnancy. This increase in progesterone raises the body temperature very slightly – usually less than half a degree (F). By detecting this rise, BBT method can identify your ovulation.
What it’s like to use the traditional BBT method
Traditionally, the BBT method has required you to wake up at the same time every morning (including on weekends, when you are on vacation or after a night out) and take your temperature before you did anything else. You’d record your temperature on a BBT chart, and when you saw a rise in your BBT, you knew you’d ovulated. With a few cycles of BBT tracking, you’d be able to predict when you were likely to ovulate next, and by extension, when your fertile window might be.
Pros & cons of the traditional BBT method
On the plus side, this is a cost-effective method of identifying ovulation and estimating the fertile window. It only requires a thermometer that can read down to 1/10 of a degree (F).
However, there are three major drawbacks to the traditional BBT method.
- Requirement for a consistent sleep schedule. First, if you have an inconsistent sleep schedule due to work, have sleep problems that prevent you from getting at least 3 hours of uninterrupted sleep, or simply don’t want to get up at the same time every day, the traditional BBT method may not be for you. Inconsistent sleep affects your body temperature, and that can really throw off your results, making it difficult to see a pattern. Stress, medications, alcohol or time zone change can also introduce temperature fluctuations.
- Learning curve and subjectivity: Second, interpretation requires some learning, and it’s subjective. The rise in the basal body temperature during ovulation is typically only half a degree, and given how many factors can influence your body temperature, seeing a clear pattern can be a challenge. Even physicians sometimes have a hard time, with one study finding that doctors can identify the time of ovulation less than 40% of the time, based on BBT charts.
- Estimation based on regularity: Third, and possibly most importantly, the traditional BBT method cannot directly tell you when you are most fertile. This method can only tell you when you ovulated, after the fact. Since the day of ovulation is the last day of your peak fertility, you may find yourself scrambling to have sex. Some women can guess at their fertile window based on the cyclical temperature pattern, but this can be particularly difficult for women with irregular cycles.
Next-gen BBT ovulation trackers
There are newer BBT-based ovulation trackers that address the difficulties associated with the traditional method – and this is the type our scientific team recommends for women who want a BBT-based ovulation tracker.
Tempdrop, our team’s top pick, is a wearable BBT tracker that monitors your temperature throughout the night as you sleep, which eliminates the need for consistent sleep schedule. The accompanying smartphone app filters out random fluctuations, charts the result and clearly shows your fertile window – no need to interpret the BBT chart yourself. The learning algorithm in the app, which also has an “irregular cycle mode,” becomes more attuned to your cycle patterns with use, making Tempdrop a viable option for even women with irregular cycles.
3. Ovulation tracking via hormone tests
Why hormone tests work
Female reproductive cycles are tightly regulated by several reproductive hormones. Driven by intricate feedback loops, the body produces more or less of each hormone, depending on where you are in your cycle, making it possible to detect your fertile window and confirm ovulation based on the levels of these hormones.
Some ovulation tests look for a single hormone, typically the luteinizing hormone (LH). Others measure LH and another hormone, like follicle-stimulating hormone (FSH), progesterone or estradiol, to get a more nuanced picture of your fertile window. LH is the hormone that is released by the pituitary gland and triggers ovulation. So, when your LH level surges, it’s a sign that you are nearing ovulation.
What it’s like to use hormone-based ovulation tracking
In general, when you use a hormone-based ovulation tracker, it’s a “wake up and pee on a stick” affair. Similar to using the traditional BBT method, hormone-based ovulation tests usually need to be done first thing in the morning, before you do anything else.
The most common hormonal ovulation tests give you a negative or positive result, based on a predetermined threshold for the particular hormone being tested. After you get a positive LH result, you have 12-36 hours until ovulation to have an intercourse.
Pros & cons of hormone-based ovulation tracking
Hormone-based ovulation trackers have been popular for several good reasons. Urine-based hormone tests are non-invasive, easy to use, and relatively accurate. This type of ovulation trackers also measures the same reproductive hormones that fertility doctors use to assess women’s fertility. Although the accuracy and precision aren’t the same as blood tests done at doctors’ offices, by some estimates, these urine tests can accurately detect an LH surge in over 95% of cases.
Traditional hormone-based ovulation trackers have a few important negatives to keep in mind.
- Non-quantitative result: Most ovulation test strips use arbitrary thresholds to give you a simple positive/negative result, rather than an exact hormone level. If your LH levels are elevated throughout your cycle (as is the case for women over 40, those with diminished ovarian reserve or many women with PCOS), you will get a false positive all the time, rendering this type of ovulation trackers useless.
- Subjective reading: Even with a seemingly simple yes/no result, you can still be squinting at faint lines on a test strip to figure out if it’s a positive or negative.
- Estimation based on regularity: An LH surge alone can only tell you that you are close to ovulation, giving you just a day or so to have sex, which can be hectic and stressful. Just like the BBT-based ovulation trackers, after a few cycles of testing, you can learn to estimate your fertile window, but for women with irregular cycles, this can be quite tricky.
- Cost: You need a test strip for each ovulation test, and in most cases, you’ll test on multiple days each cycle, lest you miss the critical ovulation day. Because of that, hormone-based ovulation trackers can add up over time, especially compared to the BBT or cervical mucus method.
Next-gen ovulation trackers based on hormone tests:
In recent years, multiple companies have come out with more advanced ovulation trackers, built on the traditional hormone test-based OPKs. Most of the new trackers combine various newer testing technologies with more objective, algorithm-based interpretation and prediction, designed to overcome the drawbacks of the traditional OPKs.
In this category, our scientific team’s top picks are Proov Predict & Confirm Kit and Oova. Both test for two hormones: LH and progesterone (or, more precisely, its urine metabolite, PdG). They leverage unique algorithms to scan, read and interpret the results to predict your fertile window with more accuracy.
Proov has been the leader in the innovative ovulation tracker category. Proov’s Predict & Confirm Kit confirms ovulation with quantitative LH results. The kit also uniquely gives you an ovulation score each cycle, by measuring the PdG levels for several days after ovulation. This patented methodology gives you a better sense of the hormonal environment that supports implantation – the important next step after ovulation and fertilization. Proov’s app guides you each day on what to test, and its algorithm accurately predicts your most fertile days, eliminating the need for guesswork – all at an affordable price point rare in the advanced ovulation tracker category.
Oova, which launched direct-to-consumer during the pandemic to help fertility patients test hormone levels at home, combines cutting-edge quantitative immunoassay with an AI-driven app to accurately measure LH and PdG levels, interpret the results and clearly indicate the fertile window. Because Oova’s tests are quantitative, rather than a positive/negative based on an arbitrary threshold, Oova is a viable option for women with short, long or irregular cycles. Moreover, with Oova, you just need one test strip each morning to test two hormones. For women under the care of a reproductive endocrinologist, Oova’s HIPAA-compliant data sharing with doctors (if they are a part of the Oova network) is an added bonus.
How to find the best ovulation tracker for you
The three major types of ovulation trackers all have pros and cons, although the more advanced newcomers, like the ones our scientific team has selected, address many of the drawbacks. The bottom line is that tracking ovulation is one of the most effective ways to speed up your conception journey, and ovulation trackers can be a big help in that regard.
The selection will really come down to what you prefer and what you want, based on the ease of use, cost, length of fertile window you get, your cycle pattern and so on. Please reach out if we can help you select one that fits you best – we are with you.
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