Urine LH ovulation prediction tests are now available in a range of sensitivities. This can make buying choices confusing.
The WHO still recommends 40miu/ml as the cut off for professional urine ovulation prediction. For this reason all professional packs of LH tests will universally cut off at 40miu, which makes comparison between brands easy.
When it comes to home tests there is no longer an international agreed cut off level. Different brands have different sensitivies and in some cases brands offer an ultra option. Levels of detection for a positive result vary from 20miu, through 25miu to 30miu.
This makes choosing an LH test a matter of trial and error, as the more sensitive tests are not suitable for every user, and the same is true for the less sensitive urine ovulation tests also. This is because every women’s LH physiology is slightly different, and to a degree varies each cycle. In some women a 40miu test will never give a clear positive result, the test line simply darkening around the peak, but never exceeding the control comparison. These women should try a 25 or 30 miu LH test for a series of 3 cycles to find a test which for their LH urine excretion gives a clear positive result. Only those who still find no clear positives should move to the 20miu membrane, as for most users this would give a positive result far too early in each cycle to be any use at indicating ovulation, indeed for some this test will be positive for over half each cycle,
Expect a 3 cycle trial when you start any test brand, get to know the test and stick with it. Avoid changing brands when you find one that works, changing tests during a cycle will almost inevitable confuse you, comparing 2 brands simultaneously in the same cycle is very likely to give conflicting results and better still use tests from the same batch throughout a complete test cycle. Many testers combine LH testing with BBT monitoring in the trial phase to assist in identifying the peak LH test result for them (helps decide if you should try a more sensitive test)
What’s the sensitivity of Clearblue visual, clearblue digital and First Response ovulation tests ? This has never been revealed by the manufacturers and it is probably tweaked in response to commercial pressures each time a NEW version is released and the previous line goes into generic manufacture for supermarket own brand options.