#290 : Does Extending the Time Interval Between hCG Trigger and Oocyte Retrieval from 36 to 37 Hours Affect the Rate of Euploid Blastocysts?
Elad Barber, Daniel Lantsberg, Yossi Mizrachi, Rebecca Kelley, Kathryn Gurner, Sharyn Stock-Myer, David Gardner- General Medicine
Background and Aims: Data are lacking regarding the optimal time interval between human chorionic gonadotropin (hCG) administration and ovum pick-up (hCG-OPU interval), and its impact on blastocyst euploidy. Our aim was to compare the blastocyst euploidy rate between IVF cycles with hCG-OPU interval of 36 and 37 h.
Method: In this historic cohort study, we reviewed all hCG-triggered, PGT-A, IVF cycles performed in a single clinic, between 2018 and 2022. Commencing in September 2021, clinicians gradually changed the hCG-OPU interval from 37 to 36 h. We compared the outcomes of cycles with hCG-OPU interval of 36 h (35.5-36.5) to 37 h (36.6-37.5). The primary outcome was the number of euploid embryos. Cycles with oocyte donation, and cycles utilized GnRH-agonist triggers or dual-triggers were excluded.
Results: The euploidy rates were similar between the 36-h group (n=2,584) and 37 h group (n=5,575; 39.7% vs. 38.8%, respectively, p=0.42).
Compared to the 36-h group, patients in the 37-h group were characterized by higher numbers of total oocytes collected (15.9±8.9 vs. 17.3±9.8, respectively, p<0.001), mature (MII) oocytes (8.3±8.2 vs. 9.6±9.6, respectively, p<0.001) and 2PN embryos (9.8±5.5 vs. 10.3±6.4, respectively, p<0.001). On multivariate logistic regression analysis, the hCG-OPU interval was not associated with euploidy (aOR 0.91, 95% CI 0.82-1.01), after controlling for female and male ages, female BMI, and number of oocytes collected.
Conclusion: hCG-OPU intervals of 36 and 37 h resulted in similar blastocyst euploidy rates in IVF cycles. This finding has the potential to aid the decision-making processes when managing IVF procedures.
The 37-h group was characterized by a lower female age and higher doses of gonadotropins and consequentially more eggs collected, mature eggs and 2PN embryos compared to the patients of the 36 h group. Nonetheless, the two groups had comparable rates of euploid embryos reinforcing our primary finding.
Data are presented as mean ± standard deviation or n (%); hCG- Human chorionic gonadotropin; OPU- ovum pickup; BMI- BMI kg/m2, Gonadotropins- in IU; ICSI- Intra cytoplasmic sperm injection.
Data are presented as mean ± standard deviation or n (%); hCG- Human chorionic gonadotropin; OPU- ovum pickup; 2PN- 2 Pronuclei.