We spent 18 months ttc and were finally successful naturally, just at the point at deciding whether to opt in for IUI.
From my research and the tests we had done, I would say that there is little point in going ahead with IUI and paying for it (and would say the same about IVF) until they know that you're tubes are open, you're ovulating regularly, your egg reserve is good, you don't suffer from endometriosis, and then that your DH sperm count and quality is good enough.
The former tests for you are important (imo) you can have blocked tubes (either partially or fully) and endometriosis without any known complications, and you really have no way of knowing about egg reserve, the quality of them etc until they do tests (see here for some of the basics www.fertilityauthority.com/fertility-tests/blood-tests-infertility) Age isn't necessarily an indicator here; you can be in your 20's and have low reserve etc. Sperm tests are also v important as they are a major cause of infertility, but often one of the last things to be considered.
I think it depends on your approach, but I wanted the tests done first before we embarked on anything else, as it helps to pinpoint what method to follow. My Dr told me that if sperm counts are below par and these can't be remedied or you have egg reserve problems, then IUI is probably not the solution.
I also read (and this is probably open to further research) that success rates for IUI over 35 are about 10-15%, which ultimately put me off (I'm 38) as I figured we'd have a good chance ourselves with timed intercourse, given our tests came back negative.
My Dr gave us the following options (we're in the US so might be a bit different)
- timed intercourse with clinic monitoring (to see when I was fertile - bit pointless as I already knew)
- timed intercourse with fertility meds and monitoring to stimulate ovulation
- low dose fertility meds, monitoring and IUI
- high dose fertility med. monitoring and IUI
Not sure if you've read The Impatient Woman's Guide to Getting Pregnant, and Expecting Better; some interesting stats there on what to look for, research on success rates etc