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IVF BIG DATA

ASRM 2019 · Poster presentation

Association between the number of oocytes retrieved, cancellation rates, and clinical outcomes in IVF PGT cycles with single embryo transfer — a 2,273-cycle review

O. O. Barash, K. A. Ivani, N. Huen, M. D. Hinckley, M. V. Homer, L. N. Weckstein

Reproductive Science Center of the San Francisco Bay Area, USA

ASRM 2019 Annual Scientific Congress

2,273

IVF PGT cycles

Jan 2013 – Jan 2019 · 1,741 patients

26,677

Mature (M2) oocytes

11.6 ± 7.85 per cycle

1,601

Single embryo transfers

Euploid SET (FET)

67.6 %

Ongoing PR · >10 eggs

vs 70.7 % in 1–5 eggs · p = 0.617

Background

Why this study

The number of chromosomal aneuploidies in preimplantation embryos progressively increases with advancing maternal age. The combined effect of diminished ovarian response and increased aneuploidy rates in the older patient population is manifested in an increased proportion of IVF PGT cycles where no euploid embryos are detected.

Objective. Assess the correlation between the number of oocytes retrieved, cancellation rates, and clinical outcomes in IVF PGT cycles with single embryo transfer.

Materials & Methods

Cohort and analysis

  • Design. Retrospective review of IVF PGT cycles to identify differences in cancellation rates (no biopsy or no euploid embryos) and clinical PR based on the number of mature oocytes.
  • Period. January 2013 – January 2019; 2,273 cycles, 1,741 patients, mean age 36.9 ± 4.9 y.o.
  • Transfer workflow. All embryos vitrified after biopsy; selected embryos thawed for hormone-replacement frozen ET. Clinical PR defined by fetal heartbeat at 6–7 weeks.
  • Sub-cohorts. 242 cycles with no embryo meeting biopsy criteria; 487 cycles with all embryos aneuploid; 1,544 cycles with at least one euploid embryo (1,601 SETs).

Results · Cancellation

Older patients face dramatically higher cycle cancellation, even with many eggs retrieved

The largest age-dependent gap was in PGT cycles where > 10 eggs were retrieved — 8.7 % cancellation in patients ≤ 37 y.o. vs 51.9 % in patients ≥ 41 y.o. (χ² = 215.72, OR = 0.088, 95 % CI 0.061 – 0.126, p < 0.05).

The gap was also significant for lower yields: for 1–5 eggs retrieved — 54.4 % vs 85.9 % (χ² = 15.91, p < 0.05); for 6–10 eggs — 29.2 % vs 62.1 % (χ² = 50.51, p < 0.05).

0255075100Cancellation rate, %54.485.91–5 eggs29.262.16–10 eggs8.751.9>10 eggs≤ 37 y.o.≥ 41 y.o.
Fig. 2 — PGT-cycle cancellation rate by age group and number of oocytes retrieved.

Results · SET outcomes

Once a euploid embryo is available, outcomes are independent of egg yield

Ongoing clinical PR per SET was not statistically different between PGT cycles where 1–5 and > 10 eggs were retrieved — 70.7 % (41/58) vs 67.6 % (870/1,288) (χ² = 0.25, OR = 1.159, 95 % CI 0.651 – 2.064, p = 0.617).

Live-birth rate (LBR) after SET followed the same pattern — 66.6 % (26/39) with 1–5 oocytes, 65.1 % (71/109) with 6–10 oocytes, and 61.7 % (577/936) with ≥ 6 oocytes (χ² = 0.4, p = 0.527).

No significant difference was found between elective and non-elective SET — 66.3 % (822/1,239) vs 65.7 % (236/359) (χ² = 0.046, p = 0.831, OR = 1.027, 95 % CI 0.802 – 1.316).

Conclusion

Summary of findings

Ongoing PR and LBR in PGT cycles after SET are independent of the number of eggs retrieved and of maternal age. At the same time, diminished ovarian response and high aneuploidy rates in the older patient population significantly increase the risk of cycle cancellation. Cancellation rates should therefore be factored into patient consultation and future treatment strategy.

References

Cited works

  1. 1.Bisignano A, Wells D, Harton G, Munné S. Reply: PGD and aneuploidy screening for 24 chromosomes by genome-wide SNP analysis: a responsible path towards greater utility. Reprod Biomed Online. 2012 Jan;24(1):4–5. PubMed
  2. 2.Fragouli E, Alfarawati S, Spath K, et al. The origin and impact of embryonic aneuploidy. Hum Genet. 2013;132:1001–1013. PubMed
  3. 3.Schoolcraft WB, Katz-Jaffe MG. Comprehensive chromosome screening of trophectoderm with vitrification facilitates elective single-embryo transfer for infertile women with advanced maternal age. Fertil Steril. 2013;100:615–619. PubMed
  4. 4.Harper JC, Harton G. The use of arrays in PGD/PGS. Fertil Steril. 2010;94:1173–1177. PubMed

Reprint requests

Oleksii Barash, Ph.D. · ivfbigdata@gmail.com