SMART Protocol vs Antagonist Protocol in IVF

This retrospective study aims to assess the effect of adding letrozole in patients who have previously undergone an IVF cycle with either an antagonist or short protocol, with patients who have undergone a second cycle of IVF with an antagonist or short protocol without the addition of letrozole.

Inclusion Criteria for the SMART IVF protocol:Women between the ages of 20 and 42 inclusivelyWomen proceeding with a SMART IVF protocol following an antagonist IVF protocol between 2010 and 2020 (study group) or women proceeding with an antagonist protocol following an antagonist IVF protocol between 2010 and 2020 (control group)Delay of 1 year between both IVF cycleExclusion Criteria:Women undergoing fertility preservationOocyte donation IVF cyclesDiagnosed severe male factor requiring surgical sperm extraction (micro-tese or TESA)