Contraception on Targeted Therapy: — Which Methods Are Safe?

Yes, you can. Periods often become irregular or stop entirely on targeted therapy, but this does not mean ovulation has stopped. Ovulation can occur without a visible period, and it happens before a period would appear — so you can be fertile with no warning sign at all. This is one of the most common reasons for unplanned pregnancy during cancer treatment. Contraception remains necessary even if you have not had a period in several months.

Tell your oncology team as soon as you know. They will not judge you, and they need to know immediately because decisions about continuing or pausing treatment cannot wait. The situation is managed case by case, with input from your oncologist and a maternal-fetal medicine specialist. Early disclosure gives the most options; waiting reduces them. If you are afraid to speak to your oncologist directly, ask to speak with a nurse or counsellor first — they can support you in having that conversation.

Your team will raise contraception as a standard clinical question regardless of your relationship status. The recommendation applies whenever pregnancy is biologically possible, and situations change during a treatment period that can last many months. Using a reliable method throughout — even if you do not expect to need it — removes one serious risk from an already complicated time. An IUD, for example, requires nothing daily once it is in place and can be removed whenever your circumstances change.

Tell your team. Barrier methods — condoms and diaphragms, used consistently and correctly — offer meaningful protection and have no drug interactions. Their effectiveness in typical use is lower than long-acting methods, so your team will want to ensure you understand that gap and have support in using them reliably every time. Abstinence is also medically recognised if that is a genuine choice you are making for the full treatment period. Whatever you decide, your team needs to know and agree that it provides adequate protection for your specific drug.

In many cases, yes — but the timing depends on your platelet count and immune status at that point. IUD insertion is a minor procedure that carries a small infection risk, which matters more when your immunity is suppressed. Your oncologist and gynaecologist need to agree on when it is safe to proceed. If an IUD appeals to you, raise it at your first appointment so there is time to plan the insertion before treatment starts, when your blood counts are likely to be at their strongest.

It depends on the drug, the dose, and your age. Some targeted therapies have little known impact on egg or sperm production; others may affect it temporarily or, less commonly, more lastingly. The honest answer is that evidence on long-term fertility after many newer targeted agents is still accumulating — these treatments have only been widely used for a relatively short time. ASCO recommends that oncofertility counselling — a discussion with a fertility specialist about your personal risk — happens before treatment starts for any patient of reproductive age. Ask your oncologist for a referral; it does not commit you to any procedure.