RESULTS OF PGD FOR INFERTILITY IN 3597 CYCLES

1 Munné S, 1 Fischer J, 1 Warner A, 1 Cohen J, 2 Chen S, 3 Zouves C, 4 Barnes F, 5 Werlin L, 6 Pagidas K, 7 Hill J, 8 Schoolcraft W, 9 Ary B, 10 Wagner C, 11 Zarutskie P, and other Reprogenetics referring centers*

1 Reprogenetics, West Orange, NJ, 2 The Institute for Reproductive Medicine and Science of Saint Barnabas, Livingston, NJ, 3 Zouves Fertility Center, Daly City, CA, 4 IVF labs LLC, Encino, CA, 5 Coastal Fertility Medical Center, Irvine, CA, 6 Women and Infants Hospital, Providence, RI, 7 Fertility Centers of New England, Reading, MA, 8 The Center for Reproductive Medicine, Englewood, CO, 9 Reproductive Specialty Medical Center, Newport Beach, CA, 10 Highland Park IVF Laboratory, Highland Park, IL 60035, 11 Zarutskie Fertility and Endocrinology Institute, Laguna Niguel, CA. *In addition other 85 IVF centers provided less than 100 procedures per center to this study.

Introduction: Preimplantation genetic Diagnosis of aneuploidy, has been offered clinically since 1993, but it is not until the last few years that through the use of reference PGD laboratories, the technique is available to all USA-based IVF centers. This is the summary of the Reprogenetics experience.

Material and methods: PGD cycles included are from 1995 to 2004. Samples were sent to our laboratory by same day or next day special delivery, and results given on day 3 to 5. Probes used evolved from 5 to 9 chromosomes, using two consecutive FISH hybridizations.

Results: A total of 3597 cycles were performed, with an average maternal age of 39.41 years. Of those 3187 received a replacement (88.6%). 410 cycles had no replacement as all embryos were found to be abnormal. Information regarding pregnancy results was obtained from 2323 cycles, of which 835 became pregnant with presence of a fetal heartbeat, for a total of 1018 fetal heartbeats. Of those, 9 were ectopics, 112 spontaneously aborted, 30 were elective reductions, 360 are still ongoing, and 506 delivered. Of the 1018 FHBs, 6 (0.6%) were PGD misdiagnoses (a monosomy X, two trisomy 21s, a trisomy 13, a trisomy 15, and a mosaic trisomy X and 13). For the maternal age of these patients we would had expected 28 trisomies (p<0.001). Slides of misdiagnosis cycles were reanalyzed with telomeric probes binding to different locus, and the same results were obtained in 4 of the 6 slides, indicating mosaicism as the most probable cause (one misdiagnosis was indeed 48,XXX+13/46,XX). One misdiagnosis was due to an overlap between the Y chromosome probe (labeled orange and aqua) and the 15 chromosome probe, labeled in orange. The other misdiagnosis was due to poor fixation.

Discussion: PGD for aneuploidy is not an experimental procedure anymore.   The number of cycles performed every year is growing markedly.   A few hurdles need to be solved such as 5 color probes in the second panel of probes, to avoid misdiagnoses by overlaps, and improvement in the quality control of fixation. Reducing the misdiagnosis rate of 0.4% (once overlaps and fixation problems are solved) can only be achieved with blastocyst biopsy, still experimental; biopsing two blastomeres, which is proven to reduce implantation potential. A recently proposed alternative is to biopsing a blastomere and two polar bodies, which involves at least two micromanipulation procedures. This may also affect developmental potential, while increasing cost and complexity. The error rate due to mosaicism may decrease for female-origin aneuploidies but not for male or post-zygotic ones.