The majority of women who have a regular menstrual cycle of 26-28 days tend to ovulate. Women with cycles longer than 35 days or shorter than 25 days usually have problems with ovulation.
Methods to check for ovulation
There appear to be different methods that help us check when ovulation occurs with a great deal of accuracy. Some methods can be conducted at home and for others a medical examination is necessary.
- Cervical mucus test
The cervical mucus one day prior to ovulation is increased and is transparent and very stretchy. Although the test is not always accurate, since many women have small amount of mucus and could still ovulate, it can be used to estimate the forthcoming ovulation.The production of mucus happens 10-24 hours before ovulation. Right after ovulation, progesterone increases and the mucus gets less transparent and less stretchy.
- Ovulation test
The most accurate method for defining the exact day of ovulation is the LH urine test (the surge of the LH hormone is detected in the urine 36 hours before ovulation). There are many LH ovulation tests in the market with which a woman can check her urine daily from the 9th day of her cycle for detection of the LH surge.In most women the LH production happens in the early morning hours and its detection is done with the early morning urine test.
If the test is positive for the LH surge, the woman is advised to have sexual intercourse the same day and the day after. This ovulation test is very easy and accurate as it proves in 90% of the cases that a woman has ovulated.
- Ultrasound scan
An ultrasound scan on the 9th day of the cycle of a woman with regular menstrual cycles shows the existence of an ovarian follicle of 12-15 mm. This follicle, most of the times, grows at a rate of 1-2 mm per day until it reaches 18-22 mm diameter, when ovulation occurs.The advantage of this method is that ovulation can be proved. Therefore is very useful test and necessary to be conducted at least once in every woman with a fertility problem, in order to prove the existence of ovulation.
In some cases, if the ovarian follicle keeps growing due to insufficient production of LH or other problems, ovulation does not occur. As a result, a cyst is produced or a follicle that is shrunk without being broken.
- Progesterone test
Right after ovulation, the ovarian follicle produces progesterone. Progesterone gradually increases for the next 7 days and reaches its peak the 7th day after ovulation. As a result, the measurement of progesterone the 21th day of a 28 day cycle can identify the existence of ovulation. A value of progesterone higher than 15 ng/ml is indicative that ovulation has occurred.In women with menstrual cycles shorter or longer than 28 days, the measurement of progesterone should be conducted 7 days before the expected period.
- Temperature test
Another method of checking if a woman is ovulating is by measuring her temperature. Since the woman has to measure her temperature on a daily basis every month, is considered a time consuming and stressful method.The temperature remains stable the first days of the cycle, whereas 24 hours before ovulation there is a minor decrease that is accompanied with an increase the day after ovulation. In ovulatory cycles the increase of the temperature is prolonged for many days, as a result of the production of progesterone.
The temperature should be measured every morning, putting a thermometer under the tongue for about 3 minutes before any other activity. Even the brushing of the teeth can affect the result.
Τhe method unfortunately is not very reliable. Another drawback is that the identification of the ovulation day is done after ovulation has occurred.