Iuis in a row or with gaps?

[Tigr]

I was reading that for unknown reasons the chances of pregnancy with iui increase for the first 3 rounds and 3 iuis are more successful per cycle (~divided by 3) than one iui. For this effect, do the iuis need to be back to back or is a break of a month or so not affecting the chances? I feel like AF is on the way and should start thinking about when to start the next round.