Risks of fertility preservation treatments
Throughout treatment, we work closely with the team planning
cancer treatment, to minimise any risk to the patient or delay to
their cancer treatment.
1. Delay to cancer
When the intention is to freeze eggs or embryos, ovarian
stimulation can start at any time in the menstrual cycle as there
is no need to ensure that the lining of the womb is at the same
stage of the cycle as the ovaries. However, ovarian stimulation
takes a minimum of just over two weeks. It is therefore crucial
that patients are referred as early as possible in their treatment
pathway to give them the opportunity to consider fertility
treatment if they wish without delay to their oncology treatment.
In some cases, such as acute leukaemia, any delay to the start of
chemotherapy may be significantly detrimental and these patients
are not able to freeze eggs or embryos although male patients would
usually have time to freeze a semen sample.
2. Risk of high oestrogen
levels during stimulation
High levels of oestrogen are seen during ovarian stimulation
cycles. This could pose a risk to women diagnosed with an oestrogen
sensitive breast cancer. Addition of the drug Letrozole is
associated with significantly lower oestrogen levels and we use
this routinely for oestrogen positive breast cancer patients. There
are no large, long term follow studies, but early data has not
demonstrated an increased risk of recurrence or disease progression
in these patients.
3. Risk from egg
There is a potential risk for patients with ovarian malignancies
that, following egg collection, there could be a spill of malignant
cells from the ovary into the peritoneal cavity, although in
practice this is rarely thought to be significant. We always
discuss this with the oncologist to minimise risk.
hyperstimulation syndrome (OHSS)
OHSS is a complication seen in approximately 1% of patients
undergoing a cycle of ovarian hyperstimulation for egg recovery.
The risk is no higher in fertility preservation patients, but we
usually continue with drug therapy for one week after egg
collection to try to reduce the risk further, so that the woman is
in the best position to commence her oncology treatment.