Cytoplasmic transfer: a solution for patients with poor oocyte quality and multiple in-vitro fertilization failures?

Abstract

Objective: Women presenting with multiple in-vitro fertilization (IVF) failures present an especially difficult challenge to reproductive endocrinologists. Cytoplasmic transfer has recently been described as a potential solution to overcome this problem.Design: This was a prospective trial where women presenting with poor oocyte quality and multiple IVF failures between June 1999 and February 2001 were recruited and offered cytoplasmic transfer instead of egg donation as an adjunct to traditional IVF during the next assisted reproduction cycle.Materials/Methods: All women presenting with multiple IVF failures and poor oocyte quality were considered eligible. The metaphase II oocytes of recipients were injected with their husband’s spermatozoa and cytoplasm aspirated from either fresh donor oocytes or cryopreserved-thawed tripronucleate zygotes of donors.Results: Twenty one women were entered in the study; overall pregnancy rate was 10/21 (48%). There were 3 miscarriages, 3 ongoing pregnancies and 4 livebirths, all with normal karyotypes. All ongoing pregnancies occurred in women less than 40 years of age (n = 17). The pregnancy rate was higher in the subgroup of women under 40 receiving fresh cytoplasm (8/13 pregnant: 4 livebirths, 3 ongoing, 1 miscarriage) when compared to those receiving cytoplasm from cryopreserved tripronucleate zygotes (1/4 pregnant: 0 livebirths). All women (n = 4) over 40 received fresh cytoplasm; only one conceived and miscarried.Conclusions: Cytoplasmic transfer may be a solution for women under forty with poor oocyte quality and multiple prior IVF failures; cytoplasm from fresh donor oocytes may prove superior to that from cryopreserved tripronucleate zygotes. Further studies are needed to confirm our findings. Objective: Women presenting with multiple in-vitro fertilization (IVF) failures present an especially difficult challenge to reproductive endocrinologists. Cytoplasmic transfer has recently been described as a potential solution to overcome this problem. Design: This was a prospective trial where women presenting with poor oocyte quality and multiple IVF failures between June 1999 and February 2001 were recruited and offered cytoplasmic transfer instead of egg donation as an adjunct to traditional IVF during the next assisted reproduction cycle. Materials/Methods: All women presenting with multiple IVF failures and poor oocyte quality were considered eligible. The metaphase II oocytes of recipients were injected with their husband’s spermatozoa and cytoplasm aspirated from either fresh donor oocytes or cryopreserved-thawed tripronucleate zygotes of donors. Results: Twenty one women were entered in the study; overall pregnancy rate was 10/21 (48%). There were 3 miscarriages, 3 ongoing pregnancies and 4 livebirths, all with normal karyotypes. All ongoing pregnancies occurred in women less than 40 years of age (n = 17). The pregnancy rate was higher in the subgroup of women under 40 receiving fresh cytoplasm (8/13 pregnant: 4 livebirths, 3 ongoing, 1 miscarriage) when compared to those receiving cytoplasm from cryopreserved tripronucleate zygotes (1/4 pregnant: 0 livebirths). All women (n = 4) over 40 received fresh cytoplasm; only one conceived and miscarried. Conclusions: Cytoplasmic transfer may be a solution for women under forty with poor oocyte quality and multiple prior IVF failures; cytoplasm from fresh donor oocytes may prove superior to that from cryopreserved tripronucleate zygotes. Further studies are needed to confirm our findings.