P-586 Adding letrozole to gonadotropins during ovarian stimulation for IVF results in a similar cumulative live birth rate at lower costs following a failed IVF cycle
Bibliographic record
Abstract
Abstract Study question Following a failed IVF cycle, does adding letrozole for the first 5 days of a repeated cycle have any advantage versus repeating the same protocol? Summary answer Following a failed IVF cycle, letrozole supplementation during ovarian stimulation for IVF results in a similar cumulative live birth rate (CLBR) with 22% less gonadotropins. What is known already Letrozole results in an increase of intraovarian androgen concentration, which augments follicular stimulating hormone (FSH) receptor expression on granulosa cells and follicular responsiveness to exogenous gonadotropins. Letrozole co-treatment with gonadotropins during controlled ovarian stimulation (COH) for IVF has been investigated mainly in poor and normo-responders with conflicting clinical outcomes. This is the first and largest study that investigates the effects of adding letrozole for the first five days of COH for IVF, in GnRH antagonist cycles, to a category of patients who had a prior failed stimulated IVF cycle using the same protocol. Study design, size, duration This is retrospective monocentric study of 426 patients, with a prior failed stimulated IVF cycle using an antagonist protocol, who underwent a second cycle between 2012 and 2017. In those patients, we studied the clinical outcomes of doing a repeated cycle, using the same protocol with the addition of 5mg of letrozole daily in the first 5 days of the cycle (Group A, N = 213) versus doing a repeated similar cycle without letrozole (Group B, N = 213). Participants/materials, setting, methods Groups A and B were matched for age, body mass index, anti-mullerian hormone and infertility diagnosis. Statistical analyses were carried out using student t test, Anova and linear regression models. The primary outcome was the CLBR. Secondary outcomes included the number of mature follicles, the number of mature oocytes (MII), the number of usable embryos, clinical pregnancy rates (CPR), live birth rates (LBR) and the total dose of gonadotropins administered. Main results and the role of chance This is the first study that investigates the effects of co-treatment with letrozole during COH for IVF in the category of patients who had a prior failed IVF cycle. Our results show that patients who received letrozole during COH with gonadotropins, versus gonadotropins alone, had a significantly lower number of MII oocytes (7±4.6 vs 8,2±5.0; P < 0.01). However, despite that, they had a similar number of usable embryos (1.8±1.6 vs 1.9±1.7; P = 0.31), CPR (23.5% vs 28.7%; p = 0.22), LBR per embryo transfer (16.9% vs 22.1%; p = 0.17) and CLBR (27.8% vs 25.3%; p = 0.55). A 22% lower dose of gonadotropins (3468±1389IU vs 4442±1657IU; p < 0.001) was needed to achieve similar pregnancy outcomes in the letrozole group versus the control group, resulting in lower treatment costs. Limitations, reasons for caution The retrospective nature of this study is its main limitation. Wider implications of the findings This study confirms that in women with a prior failed IVF cycle, co-treatment with letrozole results a similar cumulative live birth rate at a significant lower cost. Trial registration number NCT05677828
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".