Ovulation and fertility

Measuring basal body temperature to determine ovulation

Your temperature reflects the hormones in the female cycle. At the time of ovulation, the simultaneous release of the hormone progesterone causes your core body temperature to rise by 0.25 to 0.5°C. By measuring your morning wake-up temperature, also known as your basal body temperature, you can determine when ovulation has taken place. To do this, you must always take the measurement at the same time and in the same place.
The most accurate temperature is your core body temperature, which can be measured orally, vaginally or rectally. The data is then transferred to a cycle chart, a cycle app or a cycle computer. The results are plotted as a cycle curve, allowing you to see when the temperature rises. If the temperature remains elevated for at least 3 days, you can be sure that ovulation has taken place.

Disadvantages

Determining your fertility by measuring your basal body temperature is time-consuming and prone to error. To ensure accurate results, you should have slept for the same number of hours every night. In particular, an irregular lifestyle, shift work, travel, alcohol consumption, stress, restless sleep (e.g. due to children waking up), going to bed late, etc., directly affect the accuracy of the measurement and can distort the results. Furthermore, women often feel stressed when they think about taking the morning measurement and are afraid of missing the right time. Therefore, this method of determining ovulation is only suitable for very disciplined women with a regular lifestyle and a fairly regular cycle.

Furthermore, by measuring your basal body temperature, you can only determine retrospectively when ovulation has taken place. However, if you want to get pregnant, you need to track the time before ovulation. The chances of conception are highest around 2 days before ovulation. By relying solely on basal body temperature measurement, you miss these crucial days. Many women therefore also monitor their cervical mucus, which changes even before ovulation. A great deal of experience is required to determine fertile days using cervical mucus. Many women find it difficult to interpret cervical mucus in a way that allows them to reliably identify their fertile days.

Improved temperature method with OvulaRing

With OvulaRing, we have objectified and simplified temperature measurement. You don’t have to remember to take your temperature in the morning, nor do you need to record temperature readings or interpret temperature charts. Thanks to high-resolution measurements every 5 minutes, 288 times a day, OvulaRing delivers precise results even with irregular cycles and lifestyles. Your temperature changes slightly even before ovulation. OvulaRing detects these changes and shows you when your chances of getting pregnant are highest. For natural family planning and to support natural contraception, OvulaRing accurately indicates when your fertile days for the current cycle are over.

Determining fertility using ovulation tests (LH test)

An ovulation test measures the level of luteinising hormone (LH) in the urine. It is released in greater quantities during the fertile phase and, in a healthy cycle, triggers ovulation through a sudden surge. LH is excreted in the urine. An ovulation test can then measure the concentration of LH in the urine. Until now, it was assumed that the highest LH concentration, known as the LH surge, is reached around 24–36 hours before ovulation. So much for the theory. But be careful! An ovulation test measuring LH in urine cannot determine your ovulation exactly.

Scientists have shown that an increase in LH in urine is not always followed by ovulation. On average, the LH peak occurred 1.2 days after ovulation and not before, as previously assumed. In only 6% of cycles did the rise in LH end before ovulation. In the overwhelming majority (94%), however, LH continued to rise after ovulation, and in 60% of cycles for even longer than 3 days.
For pregnancy to occur, it is particularly important to determine the time before ovulation, as the egg only survives for about 12–24 hours. In many cases, however, the LH test only registers a positive result when it is already too late for the egg to be fertilised.

Inadequate results with persistently elevated LH levels

Ovulation tests are also unsuitable in cases of hormonal cycle disorders such as PCOS or the onset of the menopause. In these cases, the LH level is often persistently elevated, meaning the ovulation test frequently remains consistently positive. For example, elevated LH concentrations can be observed in 60% of all women with PCOS. Accurate determination of ovulation is therefore often not possible with an ovulation test! Women with long cycles require a large number of ovulation tests. Daily hormone testing is therefore not only time-consuming, but also nerve-wracking and expensive.

Your LH levels can fluctuate significantly even during the normal course of a day. Furthermore, taking antibiotics, psychotropic drugs, hormone therapy, or having conditions affecting the liver, kidneys or ovaries can compromise the reliability of the LH test. Positive or negative – the LH test is not always clear-cut, and many women have to ‘guess’. Individual variations in LH levels, as well as the sensitivity of the specific test system, further influence the result.

Hormone testing in urine alone is based on just one measurement point per day and therefore does not provide a complete overview of your cycle.

OvulaRing measures continuously

To track your individual cycle in its entirety, continuous cycle monitoring is important. If you want to get pregnant, don’t rely on inaccurate ovulation tests! OvulaRing measures your core body temperature around the clock, records 288 data points a day and reliably indicates your fertility window and ovulation, regardless of the length of your cycle or whether you suffer from a hormonal cycle disorder.

Tracking fertility and ovulation with cycle trackers and cycle computers

There are a wide variety of different cycle trackers and computers available on the market. Some determine your fertile days by measuring your temperature, e.g. on your arm, wrist or vaginally. Others measure the LH levels in your urine, the progesterone levels in your saliva or changes in your breath caused by hormones. With some, your fertile days are displayed in an app; with others, on the device itself.

All these products have the following drawback:

They are based solely on a single daily measurement or an overnight reading. This makes them prone to error and unable to continuously track your cycle. They cannot provide you with comprehensive information about your cycle health. All products available on the market are only suitable and tested for standard cycles. 70% of all women whose cycles do not conform to the standard will not receive accurate information about their ovulation and fertility using these tools.

Keep an eye on your fertility!

If you want to get pregnant, it is important not only to track your ovulation but also to keep an eye on your overall cycle health. This is only possible with continuous cycle monitoring. OvulaRing automatically measures your core body temperature every 5 minutes – 24 hours a day, every day. This is why OvulaRing can identify your fertile days even if your cycles are extremely short, very long or completely irregular. In addition, OvulaRing can help you determine whether there are signs of a hormonal cycle disorder despite ovulation. Unlike other products on the market, OvulaRing has been tested in three independent medical studies on women with a wide variety of cycles and hormonal cycle disorders, and is also suitable for them to determine their fertile days.