ASRM 2016 · Poster presentation

Association between high gonadotropin dosage, euploidy and pregnancy rates in PGT cycles

O. O. Barash, K. A. Ivani, S. P. Willman, L. N. Weckstein, E. M. Rosenbluth, D. S. Wachs, M. D. Hinckley

Reproductive Science Center of the San Francisco Bay Area, USA

ASRM 2016 Annual Scientific Congress

618

IVF PGT cycles

538 patients · 1,980 IVF controls

3,165

Embryos analyzed

5.35 ± 2.9 per case

p = 0.57

Euploidy by dose · <35 y.o.

χ² = 0.33 · 57.6 – 67.7 %

p = 0.79

Ongoing PR across groups

χ² = 0.37 · 50.0 – 72.2 %

Background

Why this study

PGT has been proven to be the most effective and reliable method for embryo selection in IVF cycles. Euploidy and blastulation rates decrease significantly with advancing maternal age; at the same time, the average dosage of gonadotropins administered during controlled ovarian stimulation increases significantly with age to recruit an adequate number of follicles.

Objective. Evaluate the association between euploidy rates, pregnancy rates, and total gonadotropin dosage administered within matched age groups in IVF PGT cycles.

Materials & Methods

Cohort and grouping

Cohort. 618 IVF PGT cycles (Jan 2013 – Jul 2016), 594 frozen ETs, 538 patients, mean age 37.7 ± 4.3 y.o.; 1,980 non-PGT IVF cycles as controls.
Groups. Total gonadotropin dose < 3,000 IU, 3,000–5,000 IU, > 5,000 IU; eggs retrieved 1–5, 5–10, 10–15, > 15; age < 35, 35–37, 38–40, ≥ 41 y.o.
Endpoint. Clinical PR by fetal heartbeat at 6–7 weeks.

Results · Stimulation intensity

Average eggs drop only modestly with age, but dose per oocyte climbs sharply

The average number of oocytes aspirated in PGT cycles decreased insignificantly with advancing maternal age. In parallel, the average amount of gonadotropins administered rose sharply — from 2,250 ± 217 IU in patients ≤ 24 y.o. to 5,190 ± 1,793 IU in patients ≥ 45 y.o. (p < 0.05).

The average number of eggs in PGT cycles where biopsy was intended but cancelled (low egg count and/or poor embryo development) was significantly lower than in cycles with biopsy — 10.43 ± 5.32 vs 16.33 ± 5.66, p < 0.05.

Results · Euploidy

Within age groups, euploidy is independent of dose and egg yield

In young patients (< 35 y.o., n = 141), euploidy ranged from 57.56 % to 67.74 % when analyzed by total gonadotropin dose, and from 59.31 % to 72.58 % when analyzed by eggs retrieved (χ² = 0.33, p = 0.568).

In older patients (≥ 41 y.o., n = 147), euploidy ranged from 24.00 % to 31.75 % by dose and 27.43 % to 40.00 % by eggs retrieved (χ² = 1.23, p = 0.267).

Bars show the euploidy-rate range across dose/egg-yield tertiles within each age subgroup.

Results · Pregnancy & cancellation

Ongoing PR is similar across groups; cancellation tracks egg yield

Ongoing PR was similar within and between age groups, regardless of total dose or number of eggs retrieved — ranging from 50.0 % to 72.2 % (p = 0.79, χ² = 0.374).

A direct correlation was observed between the number of aspirated oocytes and the proportion of cancelled PGT cycles. In patients < 40 y.o. with > 10 eggs retrieved, 86.5 % of PGT cycles produced at least one euploid embryo available for transfer.

Conclusion

Summary of findings

High gonadotropin dosage does not affect euploidy or pregnancy rates in IVF PGT cycles. Euploidy rates are defined primarily by patient age, regardless of the number of eggs retrieved.

References

Cited works

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;24(1):4–5. PubMed
2.Fragouli E, Alfarawati S, Spath K, et al. The origin and impact of embryonic aneuploidy. Hum Genet. 2013;132:1001–1013. PubMed
3.Harper JC, Harton G. The use of arrays in PGD/PGS. Fertil Steril. 2010;94:1173–1177. PubMed
4.Handyside AH. 24-chromosome copy number analysis: a comparison of available technologies. Fertil Steril. 2013;100:595–602. PubMed

Reprint requests

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