Answer from:
The best day for IUI is as soon as you ovulate, literally after ovulation. If you have a trigger injection, there are clinics that time the IUI, 36 or 40 hours, so that we inject the sperm exactly when we suspect ovulation to be happening or has just happened and this is because of the combination of factors that the sperm is waiting for the egg to be fertilised which is going to be released in the tube very soon, so we don’t want to have a lag in timing of releasing the sperm and fertilisation.
