P-237 Does PPOS improve oocyte yield at the cost of DNA Integrity? Clinical implications from a comparative study with the antagonist protocol
Bibliographic record
Abstract
Abstract Study question Does PPOS lead to higher oocyte yield and euploid conversion rates compared to the antagonist protocol, and does it compromise oocyte DNA integrity? Summary answer PPOS increases mature oocyte yield and euploid conversion rates per oocyte, but higher segmental aneuploidy rates raise concerns about potential DNA damage, warranting further investigation. What is known already Progestin-Primed Ovarian Stimulation (PPOS) is a viable alternative to antagonist protocols, offering cycle scheduling flexibility with comparable pregnancy outcomes. While some studies suggest similar embryological outcomes, limited data exist on oocyte quality, euploid conversion efficiency, and potential DNA damage. Understanding whether PPOS enhances oocyte retrieval while preserving DNA integrity is critical for optimizing individualized ovarian stimulation protocols. Study design, size, duration This retrospective cohort study was conducted at Ovo Clinic, a university-affiliated private fertility center in Montreal, Canada, analyzing 449 IVF with PGT-A cycles performed in 2023 and 2024, comparing 24 PPOS cycles with 425 antagonist cycles under the same laboratory and clinical conditions. Participants/materials, setting, methods Patients were categorized into PPOS (n = 24) and antagonist (n = 425) groups. Parameters assessed included baseline age, AMH, mature oocyte yield, euploid embryo rates, and aneuploidy rates. Quantitative variables were compared using parametric or non-parametric test depending on their distribution. Qualitative variables were assessed using the chi-square or Fisher’s exact test. A p-value < 0.05 was considered statistically significant. Main results and the role of chance Baseline characteristics were comparable between groups (age: 37.7 ± 2.9 vs. 37.7 ± 3.7 years, p = 0.48; AMH: 3.4 ± 2.7 vs. 3.1 ± 2.7 ng/mL, p = 0.56). PPOS yielded more mature oocytes (16.0 ± 12.4 vs. 11.8 ± 6.8, p = 0.18) and demonstrated a significantly higher euploid conversion rate per mature oocyte (29.8% vs. 12.6%, p < 0.001). Although euploid embryo rates per embryo were similar (44.7% vs. 44.1%, p = 0.92), segmental aneuploidy rates were significantly higher in the PPOS group (6.1% vs. 0.8%, p < 0.001). These findings suggest that while PPOS may improve oocyte retrieval efficiency, concerns remain regarding its potential impact on oocyte DNA integrity. One hypothesis to explore is whether oxidative stress induced by the PPOS protocol contributes to DNA damage, leading to increased segmental aneuploidies. Future studies should assess oxidative stress markers and DNA fragmentation in oocytes to determine if this mechanism is clinically relevant. Limitations, reasons for caution The small sample size in the PPOS group limits statistical power. As this is an exploratory study, larger, prospective trials with oxidative stress assessments are needed. Wider implications of the findings PPOS appears beneficial for patients requiring higher oocyte yields, but potential risks to DNA integrity must be considered. Future studies should refine patient selection criteria for its use. Trial registration number No
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".