To analyse the data from all controlled ovarian hyperstimulation antagonist cycles that used an agonist trigger and a freeze‐all strategy to quantify the risk of ovarian hyperstimulation syndrome (OHSS) and subsequent pregnancy rates.

Materials and Methods
A retrospective study of all women attending fertility clinics at IVF Australia, Sydney, undergoing controlled ovarian hyperstimulation (COH) using an antagonist protocol that had a subsequent gonadotropin‐releasing hormone (GnRH) agonist trigger and freezing of all oocytes or embryos. The primary outcome measure was to determine the rate of OHSS. The secondary outcome measure was the clinical pregnancy rate.

We collected data for 123 women. 25.2% were undergoing oocyte freezing and 74.8% underwent embryo freezing. There were no cases of OHSS, either early or late onset. The pregnancy rate was 31.7% after the first frozen cycle transfer with a cumulative pregnancy rate of 50% after two frozen embryo transfers.

Our results support the hypothesis that a GnRH agonist trigger and a freeze‐all approach prevents OHSS with a good pregnancy rate.