Читать книгу Assisted Reproduction Techniques - Группа авторов - Страница 182

If natural conception fails to occur despite simple interventions (as in Case History 1), there should be a low threshold to move to assisted conception if appropriate. Although the number of oocytes recovered might be low thus limiting the chance of a successful outcome, a woman may wish to take this opportunity particularly if she was unable to have prior fertility preservation. In the case described, the woman was taking a limited break after 5 years on tamoxifen. As she had not conceived after a year of trying, and already had embryos cryopreserved, she should proceed to replace her frozen embryos and preferably one at a time to avoid multiple pregnancy and maximize her overall chances of conception from the cryopreserved cycle.

IVF and replacement of frozen embryos require the use of exogenous hormones. In women with ER positive breast cancer the data currently available do not show that women undergoing ART have an increased risk of recurrence of their breast cancer [14,15]

In Case History 2, given the chemotherapy regimens the patient was administered and her irregular menstrual cycles she is likely to have a significantly reduced ovarian reserve and unlikely to conceive naturally nor have an appropriate response to ovarian stimulation. IVF using donated oocytes would be her best option. When her treatment was escalated to BEACOPP with a high risk of ovarian failure, there was a small window between cancer treatment cycles for freezing ovarian tissue for fertility preservation. This would have given her the option of having ovarian tissue transplantation (OTT) at a future date and a chance of natural conception. OTT in patients with lymphoma and breast cancer was not previously advised due to the risk of reintroducing malignant cells and inducing a recurrence of the primary cancer. Recent published series have demonstrated a successful outcome of OTT in women with these cancers after appropriate screening, with no evidence of recurrence in a follow up period of 3–5 years [16,17]. Unfortunately, in Case History 2 the persistence of a mediastinal mass increasing the anesthetic risk made this patient unsuitable for a laparoscopy to cryopreserve ovarian tissue.

In the event of ovarian failure, the option of donated oocytes or adoption remains. For those women who have received pelvic irradiation as well as chemotherapy, surrogacy can be considered.