Читать книгу Assisted Reproduction Techniques - Группа авторов - Страница 179

It is generally not recommended for conception to be attempted immediately after completion of chemotherapy. The decision about when to start trying should be made jointly with the oncologist and the gynecologist in discussion with the patient, taking into account the following factors:

1 There is a higher risk of recurrences in the first two or three years after cancer diagnosis, influenced by the stage of the disease and nodal involvement, and in the case of breast cancer, the receptor status.

2 An adequate interval needs to be provided after the cessation of chemotherapy for ovarian function to recover, and to avoid any deleterious toxic effects of the chemotherapy on developing oocytes. Given that it takes approximately six months for the primordial germ cells to develop to the stage of primary oocyte, a safety margin of at least a year is suggested.

3 However, women who have been treated with highly toxic regimens such as FEC and BEACOPP, and older women should be made aware of the higher risk of developing premature ovarian failure and may need to start as soon as deemed safe.

Taking all these factors into account, a minimum delay of at least 2–3 years following completion of chemotherapy is conventionally recommended which should take the woman past the period of greatest risk of recurrence. In estrogen‐receptor (ER) positive breast cancer this will also allow her to have completed the minimum required exposure to endocrine adjuvant therapy [10] before taking a break for pregnancy. Following cessation of tamoxifen women are advised to delay attempting conception for at least three months to minimize the risk of birth defects [11,12]. The patient should resume tamoxifen following the pregnancy.