# Gonadotropin dose selection for repeat IVF cycles in POSEIDON Groups 1 and 2

## TL;DR

This study found that increasing gonadotropin doses in repeat IVF cycles for certain patient groups did not improve live birth rates and only raised treatment costs.

## Contribution

The study provides evidence against routine dose escalation of gonadotropins in repeat IVF cycles for POSEIDON Groups 1 and 2.

## Key findings

- Higher gonadotropin doses in the second IVF cycle did not significantly improve cumulative live birth rates.
- The Additive group had higher oocyte retrieval and fertilization rates, but differences were not statistically significant.
- Increasing gonadotropin doses led to higher treatment costs without improved clinical outcomes.

## Abstract

Investigating whether increasing the dose of gonadotropins (Gn) in the second in vitro fertilization (IVF) cycle using the antagonist protocol could improve the cumulative live birth rate (CLBR) in POSEIDON Groups 1 and 2.

This retrospective study included 343 patients from POSEIDON Groups 1 and 2 who underwent two consecutive cycles of ovarian stimulation with an antagonist protocol between May 2018 and September 2022. Patients were divided into an Additive group (those who increased the Gn dosage in the second cycle) and a Control group (those who maintained or decreased the Gn dosage), with a 1:2 propensity score matching analysis. The primary outcome was the CLBR.

In the second IVF cycle, the Additive group had higher initial (191.8 vs 183.4, P=0.135) and total (2161.7 vs 1770.6, P=0.461) Gn doses compared to the Control group. The Additive group also had a higher average number of retrieved oocytes and Metaphase II (MII) oocytes, a higher two pronuclei (2PN) fertilization rate (3.3 vs 2.6, P=0.065), and higher blastocyst formation rates (44.9% vs 44.2%, P=0.937) compared to the Control group; however, these differences were not statistically significant. The Control group had a slightly higher CLBR (31.5% vs 28.9%, P=0.8), which was also not statistically significant.

For POSEIDON Groups 1 and 2, increasing the dose of Gn under the antagonist protocol increased treatment costs but did not improve the CLBR. Routine increase of Gn dose was not recommended.