Natural cycle, modified natural cycle and mild stimulation are different protocols which provide some advantages compared to conventional stimulation: lower medication cost, less injections, less invasive, low risk of ovarian hyperstimulation and multiple pregnancy. There main drawback is high cancellation rate due to premature ovulation and lack of egg recovery at the retrieval. When an embryo transfer can be performed, the cumulative pregnancy rate is similar to the results in con- ventional stimulation. Those protocols don't provide any advantage in term of results for woman with normal ovarian reserve, however it might be considered as a therapeutic alternative in poor responders.