Endometrial preparation for vitrified-warmed embryo transfer with or without GnRH-agonist pre-treatment in patients with polycystic ovary syndrome: a randomized controlled trial.

RESEARCH QUESTION: What are the effects on pregnancy outcome in patients with polycystic ovary syndrome (PCOS) in endometrial preparation cycles for vitrified-warmed embryo transfer with or without gonadotrophin releasing hormone (GnRH) agonist pre-treatment?

DESIGN: A total of 212 patients with PCOS referred to Royan Institute, Tehran, Iran, between 20 August 2017 to 20 June 2018 were included. The patients were randomly assigned to receive oestradiol after downregulation with GnRH agonist (group A) or without GnRH agonist down-regulation (group B).

RESULTS: A total of 188 patients with PCOS completed the trial, 93 patients in group A and 95 patients in group B. Basal oestradiol and LH levels were significantly higher in group B (26.66 versus 41.61, P = 0.01 and 0.93 versus 5.33, P < 0.0001, respectively). Clinical pregnancy rates were not significantly different in both groups (31.2% versus 33.7%). Similarly, no significant differences were found between groups A and B in miscarriage (9.7% versus 11.6%), implantation (0.58 versus 0.51) and live birth (21.7% versus 22.1%) rates and for medical complications during pregnancy and neonatal anomalies.

CONCLUSIONS: Our findings indicate that endometrial preparation for frozen-thawed embryo transfer with and without ovarian suppression by GnRH agonist provides similar results.