P-683 Do we need Ethnicity-Specific BMI Cut-Offs for IVF success when comparing Asians and Europeans?
Bibliographic record
Abstract
Abstract Study question Is the BMI cut-off for decreased live birth rates (LBRs) conceived by in-vitro fertilization (IVF) lower in Asian populations compared to European populations? Summary answer In both Asian and European populations, BMI≥23 kg/m² (the overweight threshold in Asian populations) was not associated with a significant decrease in LBRs. What is known already Asian populations often exhibit unique metabolic characteristics, including a higher prevalence of insulin resistance and the metabolic syndrome, which could impact IVF pregnancy outcomes. Asians are considered overweight and experience insulin resistance at a BMI≥23.0kg/m2, whereas Caucasians are classified as overweight at BMI≥25.0kg/m2 and exhibit similar rates of insulin resistance as Asians at BMIs of 23.0kg/m2. In large studies IVF success rates decrease once the BMI≥25.0kg/m2. It is possible that Asians may have IVF success rates that are lower at their ethnicity related overweight cut-offs, but it has yet to be studied. Study design, size, duration This is a retrospective cohort study analyzing data from IVF/ICSI cycles performed between 2015-2017 at two centres, one in Asia (N = 5848) and one in Europe (N = 4463). The study aimed to evaluate the impact of BMI and ethnicity on IVF reproductive outcomes. Participants/materials, setting, methods Participants included women undergoing an IVF/ICSI cycles followed by a fresh embryo transfer. The primary outcome was LBR. Data was analyzed by chi-squared tests, t-tests and a multivariable logistic regression controlling for confounders. Initially data was analyzed using BMI grouping considered normal weight (20.0-24.9kg/m2), overweight (25.0-29.9kg/m2) and obese (≥30kg/m2) by non-ethnicity-specific cut-offs. Subsequently, analyses were conducted using BMI cut-offs of 20.0-22.99 kg/m2 vs. 23.0-24.99 kg/m2, representing normal vs. overweight BMI thresholds in Asian populations. Main results and the role of chance Europeans were heavier than Asians (BMI 25.9±4.7 vs 21.5±2.2 kg/m2, p < 0.001), younger, with lower antral follicle counts (AFCs), stimulated with less gonadotropins, had less oocytes, MII oocytes, 2PN embryos, and transferable embryos (P < 0.001, all). Multivariable logistic regression adjusted for the baseline characteristics of female and male age, AFC, gonadotropins used, sperm source, and duration of infertility to calculate adjusted odds ratios (aORs). When comparing European normal weight (BMI 20.0-24.9kg/m2) (680/2033, 33.4%), to overweight (BMI 25-29.9kg/m2) (406/1574, 26.8%) and to obese (BMI ≥30kg/m2) (211/856, 24.6%), LBRs decreased (P < 0.001) and this was maintained when controlling for confounders (aOR=0.8, 95%, CI:0.7-0.9). When comparing Asian normal weight (BMI 20.0-24.9kg/m2) (879/5282, 16.6%), to overweight (BMI 25-29.9kg/m2) (89/514, 17.3%) and to obese (BMI ≥30kg/m2) (5/52, 9.6%%), LBRs were similar (P = 0.36) which remained when controlling for confounders (aOR=0.60, 95% CI:0.24-1.52). When stratifying patients by BMI 20.0-22.99kg/m2 vs. 23.0-24.99kg/m2, representing normal vs. overweight BMI cut-offs in an Asian population, there was no difference in LBRs in the Europeans (389/1126, 34.5% vs. 291/907, 32.1%, p = 0.24) or the Asians (706/4233, 16.7% vs. 173/1049, 16.5%, p = 0.88). When performing multivariable logistic regression, these BMI groupings were not a significant predictor of LBR in Europeans (aOR=0.92, 95% CI:0.78-1.10) or Asians (aOR=1.02, 95% CI:0.85-1.23). Limitations, reasons for caution The European populations in this study may not have been homogeneous, potentially including ethnicities besides Caucasians. Therefore, some participants in the European cohort may have been of Asian or African ethnicity. Additionally, the small sample size of the obese Asian subgroup may limit the generalizability of the study findings. Wider implications of the findings BMI may be a less reliable predictor of live birth rates (LBRs) in Asians than in Europeans. Asian cut-offs for overweight failed to affect LBR in Europeans or Asians. 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 | 0.001 | 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 | 0.000 | 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".