When someone is providing eggs for IVF, we have a BMI limit of 34 for any patients (male or female) requiring sedation when undergoing egg collection, embryo transfer or surgical sperm retrieval. Ideally, you want to be below 34 at the start of stimulation as it is common to gain some weight during a treatment cycle. We do not have a BMI limit for IUI. For egg recipients and IUI patients we advise to get their BMI ideally below 40 to minimise risks of diabetes and hypertensive disorders in pregnancy. However, as there is no anaesthetic involved in treatment, patients can have IUI as long as they have been informed to lose weight (unlike IVF when they strictly have to lose weight otherwise we will not collect eggs.)