Spinning, I've never had IUI but I know it is famously ineffective and generally used to placate us annoying little girls when we are desperate to move up the IVF waiting list.
IVF in this country is successful in only 25% of cases. This is because - and I strongly believe this - this country has rubbish embryologists (except for CARE (Notts and Manchester) and City Fertility, London who are twinned with Gennet in Prague and use the same pool of embryologists). CARE has superior success rates because it is one of the ludicrously few IVF clinics in the UK to have an embryoscope. This costs £750 over here but only £250 in Czech. IVF here is £4k-ish and over there it is £1570. The success rates don't even compare.
Watch this. It will tell you everything you need to know about the genius of this machine. I do not understand women (especially those using their own eggs) who pay thousands for IVF but do not utilise this piece of equipment. It is the best way by far of knowing which embryo is most likely to implant and go the full stretch. Clinics over here that do not own an embryoscope can not afford to rely on the expertise of the embryologist's naked eye (which he uses to scan the embryos only once a day, affording him only a mere snapshot in 24 hours. He cannot risk your embryos going to day five when he doesn't have the technology to watch it's complete video time-lapse development.
The upshot of this, of course, is that, 75% of the time, embryologists are unwittingly transferring embryos that would never be capable of reaching day five. Transferring embryos at day three is a massive gamble, because by day three an embryo has only reached a division of 6-9 cells, which is a long way away from becoming a hatching blastocyst at day five. Only the best will get to day five. So, to be clear: when a 'normal' woman conceives and goes on to have a pregnancy, it is a five day hatching blastocyst that has implanted. No other division of cells will do, which is where the embryoscope comes in. Without it, the embryologist can only go by his best hunch as to what he is transferring at day 3.