We never had a BFP on oral drugs or injectables with IUI, in spite of having multiple follicles each cycle. Our twins were conceived after transferring two Grade A (or Grade 1 - can't remember the grading system) embryos during an IVF cycle. We felt pretty desperate after spending all of our savings TTC, and we really wanted the best chance of a live birth so we transferred two. But I want to say that while I thought I understood the risks involved, I've since gotten a more full picture of the risks associated with twins - there are serious implications for mother and babies, even if you have di/di twins (which are generally less risky in terms of complications for the babies prior to birth). I don't think we'd make a different decision, but I guess I just want to say that while I thought twins would be a bargain, I'm now realizing that a multiple pregnancy is one that requires a great deal of planning and medical care (at least in my experience, and DW is very healthy and fit, so our doc said her risk of complications will be lower, but still substantially higher than for a woman with a singleton pregnancy).
We're also finding that our labor and delivery experience will not be what we might have hoped for. For example, we cannot use the midwives at the smaller, more mother-baby focused hospital in town, and every hospital here requires mothers of multiples to deliver in the operating room. Not exactly the experience we would have chosen, but I"m grateful for a full team of medical experts to care for my wife and babies, nonetheless.
One piece of info that our second RE pointed out to us when we were using Clomid, Femera and FSH during IUI cycles that was a bit different than what we heard from the first RE and read online. It really helped me make decisions along the way: Many docs will tell you that the rate of multiples for medicated cycles is around 15-20%. But to really understand your risk of having a multiple pregnancy, you have to consider the probability of conceiving, and multiply it by the probability of twins or higher order multiples. And if you want to know your chance of delivering multiples, you have to also take into account the probability of a spontaneous reduction of a multiple pregnancy.
For example, the figures she gave us, based on DW's age, AMH (5.8), and AFC (typically 22 or so) were:
Probability of conceiving per well-timed IUI cycle with multiple follicles 15-20%
If successful, probability of twins 20%; Probability of triplets or higher 5%.
If multiple gestation established, probability of live birth of both babies - about 60-70% (goes up as pregnancy advances, to like 80% after heart rate is detected, 95% at end of first trimester).
So overall, per cycle, our chance of ending up with a twin or high order multiples pregnancy was around 4-5%. But the chance of actually delivering twins or high order multiples is actually a bit lower than that because about a third of multiple pregnancies reduce spontaneously.
Hope that helps your decision making process...it really helped me to think of the probability overall, rather than just the somewhat high chance of twin pregnancy if conception occurs...
Edited to add one more piece of information: We are actually moving away from Seattle because we cannot afford the cost of child care for two newborns. I never even thought about the cost of child care, much less the cost for two infants. And when I started doing research, I found that waiting lists for day cares with reasonable parent reviews (but nothing fancy by any means) had about a one year wait list and offered (at best) a 10% sibling discount. For 3 ten hour days of child care w/ an in-home nanny, we were looking at $1900 per month, and for day care it was upwards of $2500/month. Now, that is in Seattle, and where you live it could be totally different, but I do wish I'd looked into the costs of child care for twins a lot sooner than I did! Not because I would have made a different decision, but I might have been able to plan better...
I hope this doesn't sound doom and gloom, I'm just keepin' it real.
And I want to say for the record, I'm thrilled about my twins. They are teaching me a lot already.
#1 ICI-BFN #2 IUI-BFN #3 IUI-BFN #4 ICI-BFN; #5 IUI-BFN; #6 IUI-BFN; #7-no follie; #8 IUI-BFN; #9 IUI-BFN; #10 IUI-BFN; #11 ICI, fresh-BFN; #12 ICI, fresh-BFN; #13 ICI, fresh-BFN; #14-cysts; #15 ICI fresh-BFN; #16 inj+IUI-BFN; #17 inj+IUI-BFN; #18 inj+IUI-BFN; #19-cyst; #20 IVF=BFP