[Controlled ovarian stimulation protocols in endometriosis patients: with antagonist or agonist?]

To compare laboratory and clinical outcomes of in vitro fertilization-embryo transfer (IVF-ET) in patients with endometriosis using antagonist protocol, long agonist protocol or prolonged agonist protocol.

Totally 313 patients with endometriosis were recruited in Reproductive Centers of the Second Affiliated Hospital of Zhejiang University School of Medicine,Jiaxing Women and Children's Hospital,and Ningbo Women and Children's Hospital from April 2017 to October 2018, including 81 patients treated with antagonist protocol (antagonist group), 148 treated with long agonist protocol (long agonist group) and 84 treated with prolonged agonist protocol (prolonged agonist group). The clinical and laboratory data of the patients were retrospectively analyzed to investigate the effect of ovarian stimulation protocols on the IVF-ET outcomes of patients with endometriosis.

The average age in the antagonist group patients was significantly higher than those in the other two groups (all P<0.05),and anti-mullerian hormone (AMH) level and antral follicle numbers were significantly lower than those in the other two groups (all P<0.01). The numbers of average retrieved oocyte, fertilized oocyte and available embryo in the antagonist group were significantly lower than those in the long agonist group (all P<0.05), but were similar with those in the prolonged agonist group (all P>0.05). Fertilization rate and available embryo rate were comparable among the three groups (all P>0.05). Considering analysis per cycle with embryo transfer, the human chorionic gonadotrophin (HCG) positive rate, clinical pregnancy rate and total implantation rate showed no significant difference among the three groups (all P>0.05). The implantation rate after fresh embryo transfer in the antagonist group was lower than that in the long agonist group (P<0.05), but was similar with that in the prolonged agonist group (P>0.05). While the implantation rate of freeze-thaw embryo transfer showed a higher trend in the antagonist group, but there was no significant difference (P>0.05). The patients were further divided into diminished and normal ovarian reserve subgroups, the per cycle with embryo transfer, the HCG positive rate, clinical pregnancy rate and total implantation rate still showed no significant difference between two subgroups (all P>0.05), no matter in which ovarian stimulation protocol groups. Besides, in women with diminished ovarian reserve, the available embryo rate in antagonist group was significantly higher than that in the long agonist group (P<0.05). The amount and duration of Gn application in antagonist group were significantly lower than those in long and prolonged agonist groups (all P<0.05).

Patients with endometriosis who used the antagonist protocol in IVF procedure could reduce the cost and time of Gn treatment, when combined with frozen-embryo transfer strategy the antagonist protocol has comparable clinical pregnancy outcome with long or prolonged agonist protocol, especially in those with diminished ovarian reserve, the higher available embryo rate can be achieved.