Minimum number of mature oocytes needed to obtain at least one euploid blastocyst according to female age in in vitro fertilization treatment cycles.
Level 3 - non-randomized controlled study
Retrospective cohort study developing and internally validating a clinical prediction model
PubMed 38848954 · doi:10.1016/j.fertnstert.2024.06.002
What was done
Retrospective cohort study analyzing 2,660 first IVF-PGT-A cycles (2,462 autologous cycles in women aged ≥35 years and 198 donor cycles aged ≤34 years) at a single private clinic in Spain between January 2017 and March 2022. All cycles had ≥1 metaphase II (MII) oocyte, and biopsies were performed on days 5 or 6 using next-generation sequencing; known abnormal karyotypes were excluded. An adjusted multivariable binary regression model was developed on 80% of the patient group to predict obtaining at least one euploid blastocyst from MII oocyte count and age, and tested on a 20% validation split (n = 493).
What was found
The mean number of MII oocytes required to obtain one euploid blastocyst and the proportion of cycles yielding zero euploids increased with age (exact numbers per age bracket were not reported in the abstract). The derived prediction calculator achieved 72.0% accuracy in predicting the attainment of at least one euploid blastocyst in the internal validation cohort.
Why it matters
This study offers an age-stratified predictive tool to help patients and clinicians estimate the mature oocyte yield needed to achieve at least one euploid embryo during IVF-PGT-A counseling.
Limits
The study is retrospective and from a single clinic system. Autologous cycles under age 35 were excluded (only donor cycles were used for ≤34 years). The model lacks external validation in other clinical settings, and key performance metrics such as calibration, discrimination (AUC-ROC), and specific numerical thresholds by age were not provided in the abstract.
Cited by
- supports In IVF, producing one viable embryo requires approximately 3 eggs at age 25 to 28, but requires roughly 10 to 15 eggs at age 40.