P-205 comparison of GnRH antagonist protocol versus progestin-primed protocol in high ovarian responders: a propensity score-matched study
Authors: Cheng W , Rui H 
Published: June 2023

Abstract

Study question
To compare the clinical outcomes and cost-efficiency between gonadotropin-releasing hormone (GnRH) antagonist and progestin-primed ovarian stimulation (PPOS) protocol in high ovarian responders.

Summary answer
Comparing with PPOS protocol, GnRH antagonist protocol was associated with shorter time to live birth, higher OHSS rate and less cost in high responders.

What is known already
For high ovarian responders prone to develop ovarian hyperstimulation syndrome (OHSS), the best option should be the GnRH antagonist, as it has been shown to significantly reduce the incidence of OHSS. By applying ovarian stimulation using the combination of antagonist with agonist trigger and embryos freezing, OHSS can be erased. PPOS protocol in combination with a freeze-all strategy has proved to be a valid alternative to the conventional stimulation protocols. Recent studies showed that comparing with antagonist protocol, a lower cumulative live birth rate (CLBR) was associated with PPOS in general population, with no data available in high responders.

Study design, size, duration
This was a propensity score-matched retrospective cohort study. From Jan. 2016 to Jan. 2023, 5810 patients with AMH &gt; 3.67ng/ml undergoing IVF treatment with antagonist or PPOS protocol at the Sixth Affiliated Hospital of Sun Yat-sen University were screened.

Participants/materials, setting, methods
Two-to-one propensity score matching was performed with a caliper of 0.2. After matching, 540 patients in GnRH antagonist group and 270 patients in PPOS group were included. Generalized estimated equation regression was applied to evaluate the impact of independent variables on the CLBR.

Main results and the role of chance
No significant difference in baseline characteristics was found in two groups. The OHSS (moderate to severe) rate was significantly higher in the GnRH antagonist group than in the PPOS group (7% vs. 3%). The clinical pregnancy rate and live birth rate per transfer were comparable between the two groups. After excluding patients who didn't achieve live birth but had surplus embryos, the CLBR was comparable between the antagonist and PPOS group (67.4% vs. 61.0%; Risk ratio = 1.106; 95% confidence interval [CI], 0.973-1.256, P = 0.109), and the generalized estimated equation regression analysis also showed that protocol selection had no significant impact on CLBR. The average time to live birth (TTLB) in the antagonist group was significantly shorter than the PPOS group (11.45 months vs. 12.13 months, P &lt; 0.05). Besides, the average cost in the antagonist group was about $4933, while it was about $5465 in the PPOS group.

Limitations, reasons for caution
Although we recruited a large sample size and the sophisticate statistical analysis method, this was a retrospective study with an intrinsic limitation, besides more patients in the PPOS group had surplus embryos than in the antagonist group (24.1% vs. 19.8%). Further prospective RCTs are required to confirm our findings.

Wider implications of the findings
For infertile patients with high ovarian reserve, the clinical outcomes were comparable between GnRH antagonist and PPOS group. The antagonist group was associated with a shorter TTLB and more cost-effective, while the PPOS was associated with a lower OHSS rate.

Trial registration number
Not Applicable