Pregnancy after cancer therapy

Dr Chris Venter clarifies when it is safe to start a pregnancy after cancer therapy.

Over the past four decades, advancements in early detection and chemotherapeutics have led to dramatic improvements in cancer survival. A large proportion of these survivors are women and men of reproductive age. One of the strongest predictors of emotional well-being is the desire to become a parent. Addressing the patient’s fertility concerns is important prior to, but also during and after cancer therapy. 

Common questions that arise are:

What effect will cancer treatment have on my fertility?

Will the cancer treatment increase my risk of having an abnormal child?

When is it safe to try and conceive?

Fertility assessment prior to cancer treatment

All patients of reproductive age need to see a reproductive specialist and be counselled regarding the risk that cancer therapy poses to their reproductive health. 

This risk differs considerably between individuals. The risks include: lowering of one’s egg reserve, sperm count, or affecting the ability of the uterus to carry a pregnancy. These risks might be transient or permanent. 

Factors like the patient’s age, current egg reserve, the type of cancer and the treatment are used to calculate this risk. Based on this risk calculation, the decision is then taken to preserve fertility or not.  

Fertility during cancer treatment

Radiation or chemotherapy targets rapidly dividing cancer cells. Unfortunately, oocytes (immature egg cells) and sperm being the innocent bystanders are equally affected. 

Radiation or chemotherapy leads to DNA damage of the eggs and sperm, and ultimately destruction of these cells. This is important, as DNA damage can persist for up to a year post-completion of chemo or radiation therapy. Chemotherapy can also disrupt the menstrual pattern of a patient and this can persist for up to two years.

It is, therefore, advisable that patients who received cancer treatment should not conceive for at least a year post-cancer treatment. The DNA damage in the sperm or eggs can cause miscarriages within this waiting period. Patients are advised to use effective contraception during this period. In certain hormone-sensitive breast cancers, this waiting period for pregnancy might be extended to a further five to 10 years. 

Fertility after cancer treatment

The oncologist will decide the appropriate time to consider a pregnancy. It is during this time that the patient needs to restart follow-up visits with the reproductive specialist. 

During these visits, the fertility specialist will determine what impact the cancer therapy had on the reproductive potential of the patient. As with most patients, there will be a negative impact on their fertility, and patients should be counselled about this and given a clear time-sensitive management plan. 

This plan can range from expectant management, to cycle monitoring or more specialised reproductive techniques. The bottom line is that these patients needs to be well-informed, supported and encouraged, making their fertility journey as atraumatic as possible. 

Females

How long will my menstruation stay away after cancer treatment?

In 30% of patients, it can be absent for one year, in 20% of patients for two years, and in 10% of patients for up to three years or longer.

Can there be abnormalities in my baby if conceived after one year of completing chemotherapy? 

No. However, there needs to be a one-year waiting period.

How long can my eggs or embryos be stored for?

Evidence have shown up to 10 years. 

Males

Can chemotherapy cause DNA sperm damage?

Yes.

How long should I wait after chemotherapy to start my family?

One year.

When should I asses my sperm count?

One year after completing the cancer therapy.

Header image by Freepik

This article is sponsored by Ferring Pharmaceuticals in collaboration with SASREG. The content and opinions expressed are entirely the medical expert’s own work and not influenced by Ferring in any way. 2019/109