Clearblue Fertility & Ovulation Products
Clearblue offers a range of fertility and ovulation products, all of which monitor luteinising hormone (LH) in urine to identify the time of peak fertility. The Clearblue Fertility Monitor and Clearblue Digital Ovulation Test with Dual Hormone Indicator also measure E3G (estrone-3-glucuronide,) a urinary metabolite of another key 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 time of high fertility 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 window are known as peak fertility days. These peak fertility days are the day prior to ovulation and the day on which ovulation takes place4.
Studies show that a surge in LH level occurs 24-36 hours prior to ovulation4, 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 conception1.
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 show that women who are aware of their fertile days have an increased likelihood of conceiving10-11.
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 mucus12. Therefore, intercourse during the 6-day fertile period may lead to conception, as sperm can survive for a number of days.
The Clearblue 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 conceive14. It accurately monitors levels of LH and E3G to typically identify 6 days of high and peak fertility per cycle. This makes the Clearblue Fertility Monitor the most advanced home method of maximising the chance of conception. Clinical studies have found urinary measurements by Clearblue Fertility Monitor closely reflect serum concentrations of the hormones8 and the LH surge detection by the monitor accurately predicts ovulation7.
The Clearblue Digital Ovulation Test with Dual Hormone Indicator 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 Digital Ovulation Test with Dual Hormone Indicator typically identifies 4 fertile days, 2 more than any other ovulation test, for more opportunities to get pregnant naturally15. The Clearblue Digital Ovulation Test with Dual Hormone Indicator is more than 99% accurate at detecting the LH surge16. The digital display shows an unmistakable result in the form of a smiley face when a fertile day is detected. Clearblue Digital Ovulation Test with Dual Hormone Indicator is available as a 10 test pack (1 month supply) or a 20 test pack (2 month supply).
The Clearblue Digital Ovulation Test is over 99% accurate in detecting the presence of LH in the urine sample17. The Clearblue Digital Ovulation Test identifies the two most fertile days by detecting this 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' hands18.
The Clearblue Digital Ovulation Test is available as a 7 Test Pack and a 20 Test Pack. The Clearblue Digital Ovulation Test - 20 Test Pack is more suited for women with irregular cycles, as it includes extra test sticks to give women a greater chance of detecting their peak fertile days19. Data show that over 40% of women experience more than 7 days cycle variability20, and for these women, using the 7 test pack may mean they miss their LH surge if they test on the wrong day. The Clearblue Digital Ovulation Test - 20 Test Pack is very easy to use as the consumer starts testing on day six (or day 12 if a typical cycle is longer than 40 days) and keeps testing each day until her LH surge is detected. Because of these extra test days, in 99% of cases a test would be conducted on the surge day (if present).19
It has been suggested that the use of home ovulation tests to time intercourse for conception can lead to emotional distress. 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 aids.21
The Clearblue Home Ovulation Test is a traditional ovulation test which 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.
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14 Robinson JE, Ellis JE. Mistiming of intercourse as a primary cause of failure to conceive: results of a survey on use of a home-use fertility monitor. Curr Med Res Opin 2007;23(2):301-6.
15 15SPD Data on file. In a study of 87 women, 4 or more fertile days were identified in 80% of cycles using actual cycle length
16 SPD Data on file. Study found >99% agreement with AutoDELFIA reference method in 100 cycles (all cycle had LH surge >40mIU/ml).
17 SPD data on file. Clearblue Digital Ovulation Test has been shown to be 99% accurate when compared to a reference method in laboratory studies using urine samples from 123 cycles in which the LH surge was identified by a reference method.
18 Johnson S, Ellis J, Godbert S, Ali S, Zinaman M. Comparison of a digital ovulation test with three popular line ovulation tests to investigate user accuracy and certainty. Expert Opin Med Dign 2011;5:467-473.
19 Johnson SR, Shaw R. Success of detection of LH surge by home ovulation tests. Fertil Steril 2009:92(3):S101.
20 Creinin MD, Keverline S, Meyn LA. How regular is regular? An analysis of menstrual cycle regularity. Contraception 2004 Oct;70(4):289-92.
21 Tiplady S, Jones G, Campbell M, Johnson S, and Ledger W. Home ovulation tests and stress in women trying to conceive: a randomized controlled trial. Human Reproduction 2013;28(1):138-151.