Pronuclear embryo cryopreservation experience: outcomes for reducing the risk of ovarian hyperstimulation syndrome and for fertility preservation in cancer patients
To evaluate pregnancy rate (PR) and live birth rate (LBR) after freezing pronuclear (PN) embryos for two purposes: to reduce the risk of ovarian hyperstimulation syndrome (OHSS) and to bank embryos for cancer patients anticipating gametotoxic chemotherapy/radiotherapy.
Data from 3,621 consecutive IVF cycles were retrospectively analyzed. PN freezing was offered to patients at risk for OHSS and for those wishing to preserve fertility prior to cancer therapy. Primary outcomes evaluated were PR and LBR. Outcomes were compared to patients who underwent fresh embryo transfer (ET) in 2006.
Sixty-six patients froze PN embryos. Thirty-eight were at risk for OHSS. The LBR was 34.3% after one transfer, and 51.4% after a mean of 1.4 transfers. Twenty-eight cancer patients froze embryos. The LBR was 16.7% after one transfer and 25.0% after a mean of 1.5 transfers. The LBR was 35.5% for patients who underwent fresh ET.
PN freezing with delayed ET is an effective tool for achieving pregnancy for patients at risk of OHSS and for cancer patients wishing to preserve fertility.
KeywordsOvarian hyperstimulation syndrome OHSS IVF Cancer Fertility preservation
Acknowledgements or Funding Sources
- 3.Mohr LR, Trounson A, Freeman L. Deep-freezing and transfer of human embryos. J IVF. 1985;2:1–10.Google Scholar
- 5.Veeck LL. Chapter 9 cryopreservation. In: An atlas of human gametes and conceptuses. New York: Parthenon; 1999. p. 69–75.Google Scholar
- 6.Rizk B, Aboulghar MA. Classification, pathophysiology, and management of ovarian hyperstimulation syndrome. In: Brinsden P, editor. In vitro fertilization and assisted reproduction. New York: Parthenon; 1999. p. 131–55.Google Scholar
- 13.Alvarez C, Alonso-Muriel I, Garcia G, Crespo J, Bellver J, Simon C, et al. Implantation is apparently unaffected by the dopamine agonist Cabergoline when administered to prevent ovarian hyperstimulation syndrome in women undergoing assisted reproduction treatment: a pilot study. Hum Reprod. 2007;22(12):3210–4.PubMedCrossRefGoogle Scholar
- 18.Queenan JT, Veeck LL, Toner JP, Oehninger S, Muasher SJ. Cryopreservation of all prezygotes in patients at risk of severe hyperstimulation does not eliminate the syndrome, but the chances of pregnancy are excellent with subsequent frozen-thaw transfers. Hum Reprod. 1997;12(7):1573–6.PubMedCrossRefGoogle Scholar
- 29.Veeck LL, Zaninovic N. Blastocyst cryopreservation and thawing. In: An atlas of human blastocysts. New York: Parthenon; 2003. p. 179.Google Scholar
- 30.American Society of Reproductive Medicine Guidelines on number of embryos transferred. Fertil Steril. 2006;86(4):S51–52.Google Scholar