LH surge detection

I'm confused about DIUI timing after three failed attempts, and reluctant to try another until I've understood something important in the process, and I didn't really understand what my doctor said when I asked her. I tested for the LH surge at home with a digital opk, in the early morning before work and again in the evening after work. I got my first positive in the evening. However, the info I was given is stated below. Does this mean that blood testing gives a positive earlier in the day than urine tests (which would give a first morning positive 24 hours after the blood test), so changing the date of the IUI depending on which tracking method is used? Given how important the timing is, this seems to add stress to the process, and I don't understand.

"Please keep in mind that while you may have the initial surge of LH earlier in the day if testing via blood tests, you will not get a positive result on the ovulation test until 4-5 hours later when the surge actually reaches your urine."


Our Expert's Answer

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I agree that there is a lot of confusion around LH testing. We advise only testing once a day with a Digital Ovulation Tests.  If your LH surge starts in the early evening then the LH will still be detected in the urine the following day. The important factor is having concentrated urine so testing at least four hours after the last urination.  Ovulation takes place 38 hours and from our experience patients have equal chance of success having an insemination either the day after the surge (just before ovulation) or 2 days after the surge (after insemination) which shows that the egg remains viable for at least a day