Clearblue offers a range of home fertility and ovulation products, all of which monitor luteinising hormone (LH) in urine to identify the time of peak fertility. The Clearblue Advanced Fertility Monitor and Clearblue Advanced Digital Ovulation Test also measure E3G (estrone-3-glucuronide), a urinary metabolite of another key female hormone, estrogen, to identify the period of high fertility that occurs prior to the LH surge. Monitoring these two hormone levels helps women identify the fertile days of their cycle enabling them to time intercourse to the days when conception is most likely.

How urinary LH and E3G can be used to identify fertile days

There are only a few days per cycle when a woman is fertile and can conceive. Evidence shows that this ‘fertile window’ usually spans 6 days, starting approximately 5 days prior to ovulation and ending on the day of ovulation itself.1 The 6-day fertile period is affected by:

  • The lifespan of the egg, which is up to 24 hours after ovulation

  • The lifespan of sperm which is more variable. The median is 1.5 days2, but sperm can generally survive for several days in the sperm supportive mucus3 found in the fertile days of the cycle. Sperm survival is therefore dependent on the type and quantity of the mucus within the cervix, and the quality of the sperm itself.

The two most fertile days of this 6-day fertile window are known as peak fertility days. These peak fertility days are the day prior to ovulation and the day on which ovulation takes place.4

Studies show that a surge in LH level occurs 24-36 hours prior to ovulation,4 and that this LH surge is an accurate and reliable marker of impending ovulation.5-9 The urinary LH surge pinpoints the two peak fertile days of a woman's cycle, with intercourse on these days being shown to be associated with the highest likelihood of conception.1

In the days leading up to the LH surge, estradiol levels rise gradually, reaching a threshold that triggers the pre-ovulatory LH surge. Tracking E3G, the urinary metabolite of estradiol, allows women to identify the days of high fertility leading up to ovulation, where conception is also possible, and this also gives them advanced notice of their peak fertile days. Data shows that women who are aware of their fertile days have an increased likelihood of conceiving.10,11

Furthermore, estradiol stimulates secretion of cervical mucus that is favourable for the survival and transport of sperm. The rise in plasma estradiol corresponds closely to the appearance of sperm-supportive cervical mucus.12 Therefore, intercourse during the 6-day fertile period may lead to conception, as sperm can survive for a number of days.

Day of Cycle

Typical changes in urinary E3G and LH during the menstrual cycle.

The Clearblue Fertility Monitor/Clearblue Advanced Fertility Monitor

The The Clearblue Fertility Monitor/Clearblue Advanced Fertility Monitor is a unique innovation proven to increase the chances of conception by 89% over the first 2 cycles of use13 which can help reduce the time it takes to conceive.14 It accurately monitors levels of LH and E3G to typically identify up to 6 days of high and peak fertility per cycle. This makes the Clearblue Fertility Monitor/Clearblue Advanced Fertility Monitor the most advanced home methods of maximising the chance of conception. Clinical studies have found urinary measurements by Clearblue Fertility Monitor/Clearblue Advanced Fertility Monitor closely reflect serum concentrations of the hormones8 and the LH surge detection by the monitor accurately predicts ovulation.7

In addition to reading the dual-hormone assay for fertility hormones on fertility Test Sticks, the Clearblue Advanced Fertility Monitor can read pregnancy Test Sticks, which contain an assay for human chorionic gonadotrophin (hCG), an established and accurate marker for pregnancy. Clearblue Advanced Fertility Monitor also allows the user to input additional data such as dates of intercourse and menses, and displays information from the previous 6 cycles in a summary chart. The Clearblue Advanced Fertility Monitor has a sleek and feminine design with the added benefit of an intuitive touch-screen display.

The Clearblue Advanced Digital Ovulation Test

The Clearblue Advanced Digital Ovulation Test accurately tracks a woman’s personal menstrual cycle to identify a wider fertile window than other home ovulation tests, by tracking the changing levels in the urinary metabolites of E3G and LH. By measuring these 2 hormones, the Clearblue Advanced Digital Ovulation Test typically identifies 4 or more fertile days, 2 more than any other home ovulation test, for more opportunities to get pregnant naturally 15. The Clearblue Advanced Digital Ovulation Test is more than 99% accurate at detecting the LH surge.16 The digital display shows an unmistakable result in the form of a smiley face when a fertile day is detected. Clearblue Advanced Digital Ovulation Test is available as a 10 test pack (1 month supply) or a 20 test pack (2 month supply).

The Clearblue Digital Ovulation Test

The Clearblue Digital Ovulation Test is over 99% accurate in detecting the presence of LH in urine.17 The Clearblue Digital Ovulation Test identifies the two most fertile days by detecting the pre-ovulatory LH surge. It is a simple home ovulation test kit, which provides easy-to-read, easy-to-understand digital results for more accurate reading in consumers' hands.18

Depending on where you live, the Clearblue Digital Ovulation Test may be available in a number of different pack sizes to accommodate the variability in women’s length of cycle. It has been suggested that the use of home ovulation tests to time intercourse for conception can lead to stress. A recent study found no difference in levels of stress between women using digital ovulation tests compared with women who were trying to conceive without any additional aids19

The Clearblue Ovulation Test

The Clearblue Ovulation Test is a traditional ovulation test with results that appear as blue lines and need to be interpreted by the user. It is an accurate method to identify the LH surge day and improve a woman's chances of conceiving.

This content is provided for general information purposes only. Always read package inserts of product before use.