You’re pregnant. You confirmed this last week by peeing on a Clearblue Digital Pregnancy Test with Weeks Indicator; a unique pregnancy test that not only informs you if you are pregnant, but also estimates how far along the pregnancy is, based on human Chorionic Gonadotropin (hCG) levels. There are actually two versions of this test available; in the UK the test is named the Clearblue Digital Pregnancy Test with Weeks Indicator, whilst in the United States the same product is called the Clearblue Advanced Pregnancy Test with Weeks Estimator.
When you performed the Clearblue Digital Pregnancy Test your pee-stick had stated ‘Pregnant’ and the Weeks Indicator had read ‘1-2.’ It’s important to note that for this particular pregnancy test the number of weeks indicated by the Weeks Indicator feature is the time that has passed since conception, not since last menstrual period. As such, ‘Pregnant 1-2’ would in fact indicate that you are 3-4 weeks pregnant expressed in the traditional manner. Correspondingly, ‘Pregnant 2-3’ on the Weeks Indicator would indicate that you are 4-5 weeks pregnant, and ‘Pregnant 3+’ would indicate that you are 5 weeks pregnant or more.
Over a week later, out of curiosity, you decide to retest with the other pee-stick from the pack of two. You do this because:
- You don’t feel super pregnant yet and so begin to wonder whether you dreamt up the whole thing
- You tell yourself that the first positive test could have been a false reading (though in actual fact a pregnancy test giving a false positive is extremely unlikely)
- You want to see on the Weeks Indicator how your pregnancy has progressed
- The second unused pregnancy test is sat there, calling your name, and you just can’t resist
You expect to see ‘Pregnant 3+’ but much to your alarm the repeated test again states ‘Pregnant 1-2.’ This is despite the fact that conception happened almost 4 weeks ago; expressed in the traditional manner you are now almost 6 weeks pregnant. You know that the Clearblue Digital Pregnancy Test works based on hCG and so you worry that your levels are lower than expected and are not rising as they should. It’s time to freak out… right?
If you are reading this article now because you are facing this exact situation, you are not alone. In fact, the above scenario is described on many fertility and pregnancy forums, always posted in an anxious panic by women who fear for their pregnancy. These fears will of course be amplified by several (unofficial) online articles which advocate the Clearblue Digital Pregnancy Test with Weeks Indicator as a tool for detecting miscarriage risk.
The thing is though, the Clearblue Digital Pregnancy Test is not designed or intended for checking pregnancy viability. This fact is written very clearly within the test’s instruction leaflet, as well as on the Clearblue website where it states that the test cannot be used to determine the duration of pregnancy or to monitor the progression of a pregnancy.
The Clearblue Digital Pregnancy Test with Weeks Indicator is designed around testing for typical urine hCG levels. HCG can usually be detected in urine about 12-14 days after conception, and typically doubles every 72 hours. If a Clearblue Digital Pregnancy Test with Weeks Indicator reads ‘Pregnant,’ it means that at least 10mIU/ml has been detected in your urine. Incidentally, this makes it one of the most sensitive home pregnancy tests around.
HCG levels of the Clearblue Digital Pregnancy Test Weeks Indicator
My Informed Life contacted Clearblue for detailed information on how the weeks indicated by the Clearblue Digital Pregnancy Test correspond to urine hCG levels. Clearblue kindly explained that the parameters for each reading are as follows:
Weeks Indicator states
Corresponds to hCG levels (mIU/ml)
|‘3+’||2600 and above|
Clearblue explained that these parameters are based on extensive research of urine hCH levels in early pregnancy.
Typical Urine HCG levels in Early Pregnancy
In one particular 2013 study by Larsen and colleagues, 153 pregnant women’s urine samples were analysed. The results suggested that typical urine hCG levels are as follows:
|Weeks since conception||Median urine hCG level found by Larsen’s study (mIU/ml)||Typical range of urine hCG level suggested by Larsen (mIU/ml)|
Clearblue stated that the Clearblue Digital Pregnancy Test with Weeks Indicator is over 99% accurate at positively confirming pregnancy, when used correctly to test the first urine of the day.
Clearblue further informed us that the Weeks Indicator part of the test is 92% accurate at providing an estimate of when a woman conceived. This tells us that the Weeks Indicator may be inaccurate 8% of the time. Whilst this is a small percentage of times, given the success of this pregnancy test, it could amount to a lot of women.
HCG levels are known to vary from one woman to the next, with many having hCG levels that do not fall within the ‘typical’ parameters. These women may well go on to sustain normal healthy pregnancies. If you are one of these women and you use the Clearblue Digital Pregnancy Test in the early stages of your pregnancy, the Weeks Indicator will likely give you an inaccurate result. Other factors such as date of ovulation, date of conception, urine dilution and the time of day that you performed the test could also have had an effect. Whilst these factors can be controlled or allowed for in research studies, the process of hovering over a pee-stick in your own bathroom cannot be so vigorously controlled.
The key point to take home is that you may see an unexpected result on your Clearblue Digital Pregnancy Test with Weeks Indicator and go on to have a perfectly healthy baby. Remember, the current medical consensus is that hCG levels should not be used to clinically date a pregnancy. The gold standard approved method of dating a pregnancy, and confirming pregnancy viability, is to count the number of weeks from your last menstrual period, and to scan your baby using ultrasound scanning techniques.
If you are worried about your own hCG levels, or you are worried about the viability of your pregnancy for any reason, you should contact your GP/physician or midwife immediately for professional clinical advice.
Adams Martinez, P.A. (2013) Can you check your miscarriage risk with a pregnancy test? [Online]. Available from: http://www.parents.com/blogs/everything-pregnancy/2013/09/12/pregnancy-news/home-pregnancy-test-estimates-miscarriage-risk/ (Last accessed 12th October 2015)
American Pregnancy Association Human Chorionic Gonadotropin (HCG) : The pregnancy hormone. [Online]. Available from: http://americanpregnancy.org/while-pregnant/hcg-levels/ (Last accessed 12th October 2015)
Clearblue (2015) Clearblue DIGITAL Pregnancy Test with Weeks Indicator. [Online]. Available from: http://uk.clearblue.com/clearblue-pregnancy-tests-range/digital-pregnancy-test-with-weeks-indicator (Last accessed 15th October 2015)
Clearblue (2015) Clearblue Advanced Pregnancy Test with Weeks Estimator. [Online]. Available from: http://www.clearblueeasy.com/advanced-pregnancy-test-with-weeks-estimator.php (Last accessed 12th October 2015)
Goldberg, C. (2013) Can new pregnancy test be used to watch for early miscarriage? [Online]. Available from: http://commonhealth.wbur.org/2013/09/pregnancy-test-miscarriage (Last accessed 12th October 2014)
Larsen, J; Buchanan, P; Johnson, S; Godbert, S; and Zinaman, M. (2013) ‘Human chorionic gonadotropin as a measure of pregnancy duration.’ International Journal of Gynecology and Obstetrics. 123 (2013), pp. 189-195
Miscarriage Association (2015) Support. [Online]. Available from: http://www.miscarriageassociation.org.uk/support/ (Last accessed 12th October 2015)
You and Your Hormones (2015) Human Chorionic Gonadotropin. [Online] Available from: http://www.yourhormones.info/hormones/human_chorionic_gonadotrophin.aspx (Last accessed 12th October 2015)
Have you or anyone you know had an experience where the Clearblue Digital Pregnancy Test with Weeks Indicator showed an incorrect result? Were you worried about miscarriage? Please comment on this article or start a discussion via a new thread. This is a newly launched web community and we would love to hear from you about your own experiences and research.