Intrauterine Insemination (IUI) is the treatment of choice for young patients with mild-to-moderate endometriosis (stages I and II). For this treatment to be possible, no blockage in the Fallopian tubes must exist. However, recent studies suggest that IUI may be ineffective in these cases. The latest European review on the average success rates during years 2016-2017 with AIH (artificial insemination by husband) are below 15% per cycle. So, in conclusion, opting for IUI in cases of mild-to-moderate endometriosis is possible in very particular cases where there is evidence that it might work.
In general, In Vitro Fertilization (IVF) is the first option for patients with a moderate or severe type of endometriosis (stages III and IV), as well as for women with previous failed cycles in spite of having a good prognosis initially.