Can Cancer Treatment Affect Pregnancy and Fertility? (2026 Information)

Chemotherapy, hormone therapy, and pelvic radiation therapy can affect ovarian or sperm function, so if you have plans to become pregnant, it's common to receive fertility preservation counseling before starting treatment. The degree of impact varies from person to person depending on the type of cancer, treatment method, and age.

Key Takeaways

• Before starting chemotherapy, patients can receive fertility preservation counseling to freeze eggs or embryos, and since preparation takes time, it's important to set a timeline before treatment begins.
• Breast cancer chemotherapy can cause menstrual periods to stop in younger patients.
• Hormone therapy for breast cancer continues for 5 to 10 years, and the timing of any pregnancy plans during treatment should be discussed with the care team.
• Preoperative radiation therapy for rectal cancer is delivered to the pelvic area and can leave effects such as diarrhea, urinary discomfort, and skin irritation.
• Hematopoietic stem cell transplantation for blood cancers takes several months to over a year for immune recovery, so overall physical recovery is managed with a long-term view.

How exactly does fertility preservation work?

• Fertility preservation refers to the procedure of freezing eggs, sperm, or embryos in advance to prepare for reproductive damage caused by chemotherapy or radiation therapy.
• According to the breast cancer notes, patients can receive counseling to freeze eggs or embryos before starting chemotherapy, and since this process takes time, it is recommended that a timeline be set together during the diagnostic reading stage.
• For cancers requiring urgent treatment, such as acute leukemia, where treatment must begin immediately after diagnosis, there may be limited time to include fertility preservation procedures, so this must be discussed together with the timing of treatment initiation.
• Whether preparation is feasible depends on the type of cancer, the stage, and how much time remains before treatment starts, so early consultation with the care team is key.

How do chemotherapy or hormone therapy affect menstruation and pregnancy?

• Breast cancer chemotherapy is described as causing nausea, hair loss, fatigue, low blood counts, and numbness in the hands and feet that come and go with each cycle, and younger patients may experience their periods stopping.
• For hormone receptor-positive breast cancer, hormone therapy continues for 5 to 10 years after surgery, with different medications used depending on pre- or post-menopausal status, and in some cases an injection to suppress ovarian function is added.
• During hormone therapy, menopause-like symptoms such as hot flashes, joint stiffness, and vaginal dryness, as well as decreased bone density, can occur, so bone density tests are performed and monitored over several years.
• If there are pregnancy plans during the hormone therapy period, whether treatment can be paused and what timing would be safe are matters that must be discussed with the care team.

Do pelvic radiation therapy or hematopoietic stem cell transplantation also have effects?

• For rectal cancer, preoperative radiation and chemotherapy are delivered to the pelvic area and can leave effects such as diarrhea, urinary discomfort, and skin irritation.
• According to the general radiation therapy notes, side effects occur only in the area where radiation passed through, with abdominal and pelvic radiation mainly causing nausea, diarrhea, and urinary discomfort; acute reactions subside over several weeks after treatment ends, but late side effects can appear months to years later, requiring long-term follow-up.
• For blood cancers, patients who undergo allogeneic hematopoietic stem cell transplantation take several months to over a year for immune recovery, and take immunosuppressants to manage graft-versus-host disease, visiting outpatient clinics frequently up to around 100 days, with management continuing for a long time afterward.
• As such, recovery periods and physical condition vary greatly depending on the treatment site and intensity, so the timing of overall physical recovery, including reproductive function, varies significantly by individual and is determined based on the care team's judgment.

FAQ — Can all cancer patients receive fertility preservation?

What is specified in the notes is that breast cancer patients can receive counseling for egg or embryo freezing before starting chemotherapy. For cancers such as acute leukemia, where treatment must begin immediately after diagnosis, there may not be enough time, so whether it is possible must be discussed with the care team along with the timing of treatment initiation.

FAQ — How soon after treatment ends can pregnancy be attempted?

The specific timing depends on the type of cancer, the treatment method (type of chemotherapy drug, radiation site, whether transplantation was performed), and the recovery status. For example, the notes indicate that hormone therapy continues for 5 to 10 years, and that after allogeneic hematopoietic stem cell transplantation, immune recovery takes several months to over a year — so rather than presenting a uniform timeframe, the timing should be set according to the individual's recovery progress in consultation with the care team.

Sources and Notes

• This content was written based on notes related to breast cancer, colorectal cancer, radiation therapy, and blood cancers (National Cancer Registration Statistics 2019–2023, National Cancer Center Korea Central Cancer Registry, National Cancer Information Center, NCCN Patient Guidelines).
• This content is intended for general medical information purposes, and diagnosis, treatment methods, and outcomes may vary depending on individual conditions. Accurate diagnosis and treatment should always be determined through consultation with a medical professional.