Printed on: May 27th, 2025

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Contraception following a diagnosis of breast or other cancers

Contraception following a diagnosis of breast or other cancers

This article was reviewed in April 2025.

Cancer can impact women of any age. Early diagnosis and development of effective treatments means that increasing numbers of women survive and continue to lead normal lives, including having active sexual lives.

• Although some cancer treatments can have a negative effect on sexual function and fertility, many women continue to be sexually active, and therefore may remain at risk of pregnancy.
• It is important to provide accurate and appropriate advice about effective contraception to these women.
• Contraceptive options may be limited by:
  • The hormone sensitivity of some cancers, and therefore risk progression or recurrence of disease.
  • Specific risks associated with a method which would be increased or more harmful in a woman with cancer.

This article summarises FSRH guidance on supporting contraceptive choices for individuals who have or have had breast cancer (fsrh-cadbc-guidance-document-15-nov-202 3.pdf), and looks at the safety of different methods of contraception with other forms of cancer.

For further information on this area, see our articles:

• Hormonal contraception: risk of cancer.
• Managing menopause after a diagnosis of breast cancer.
• Fertility and pregnancy after a diagnosis of breast cancer.

Breast cancer is the commonest cancer in women of reproductive age, accounting for around 43% of all cancers in women aged 25–49y. Around 18% of breast cancers occur in premenopausal women (Cancer Research UK - breast cancer incidence (invasive) statistics, accessed May 2025). Pregnancy should generally be avoided during breast cancer treatment. This is because:

• The hormonal state of pregnancy may affect disease progression in the short term (General and Comparative Endocrinology 2024;352:114501).
• Surgery requires anaesthesia, which should be minimised during pregnancy.
• Treatments are teratogenic or may have unknown effects on a developing foetus.

• There is consensus that, in general, women should wait to conceive for at least 2 years after treatment is comnplete because the risk of recurrence is highest during this time.
• Hormonal treatment with tamoxifen usually continues for 5 years, and is contraindicated in pregnancy due to risk of harm to the foetus, so conception within this period would mean disruption of a treatment proven to reduce recurrence.
• Discussion with specialists in oncology, fertility and obstetrics on an individual basis will enable a patient and her partner to make an informed shared decision.

 (RCOG Pregnancy and Breast Cancer Green-top Guideline no.12 March 2011)

The FSRH:

• Does NOT consider tamoxifen, aromatase inhibitors or GnRH analogues as reliable contraception. 
• Advises that women <50y who have been amenorrhoeic during or following medical treatment for breast cancer (including chemotherapy, which can cause ovarian insufficiency during treatment) may regain some ovarian activity and ovulate – irrespective of FSH levels.

FSRH guidance states that a sexually active woman SHOULD use effective contraception following a diagnosis of breast cancer UNLESS she:

• Is ≥55y.
• Is ≥50y AND has been NATURALLY amenorrhoeic for >1y (i.e. is not on any hormonal, drug or radiation treatment).
• Has had an FSH level >30 IU/L taken >1y ago AND when she was ≥50y AND before starting chemotherapy/hormone breast cancer therapy.
• Is aged 40–50y, has NOT taken any medical treatment for breast cancer AND has been naturally amenorrhoeic for >2y (FSRH - aged over 40). 
• Has had surgical treatment which would prevent pregnancy, e.g. sterilisation (or partner has been sterilised), bilateral oophorectomy or hysterectomy.

There is limited evidence looking at the risks associated with hormonal contraception use in women with a history of breast cancer. However, because breast cancer can be a hormone-sensitive disease, the FSRH takes a precautionary approach in its recommendations.

The table below lists current UK medical eligibility criteria (UKMEC) categories for the different contraceptive methods.

(Note: 1 = no restriction to use, 2 = benefits usually outweigh risks, 3 = risks usually outweigh benefits, 4 = absolute contraindication)

(UKMEC April 2016 Summary Sheet (Amended September 2019)

The FSRH recommends highly-effective non-hormonal contraception first line (ESPECIALLY for women taking teratogenic medication), specifically:

• The copper IUD.
• Female or male sterilisation.

These are around 99% effective.

• Hormonal methods should generally be avoided (see below for more on this).
• Barrier methods (condoms, diaphragms and caps + spermicide) and fertility awareness methods (including contraception apps) are medically safe, but less effective than the IUD and sterilisation.
• Fertility awareness methods that rely on menstrual cycles may be impacted by breast cancer treatments, which can cause menstrual irregularities.  

• Women who are on hormonal contraception at the time of breast cancer diagnosis should stop their method as soon as possible and switch to a non-hormonal alternative.
• If stopping contraception puts a woman at risk of unintended pregnancy, discontinuation may be delayed until the risk has passed or until specialist advice has been sought. However, CHC users should switch to an interim progestogen-only method.  

(fsrh-cadbc-guidance-document-15-nov-2023.pdf)

A healthcare professional may consider offering a progestogen-only method of contraception on an individual basis if other methods are unacceptable or inappropriate, or if there are additional gynaecological benefits from it. For example, women who:

• Would not be able to tolerate an IUD fitting or develop painful heavy periods with the method. 
• Are at increased operative risk or want to avoid a medical procedure such as sterilisation.
• Have gynaecological conditions (e.g. dysmenorrhoea, heavy menstrual bleeding, endometriosis).

This should be a patient-centred decision which includes consideration of the type and grade of tumour, as well as treatment given, and should involve a contraception specialist and breast cancer specialist. 

There is limited evidence to indicate which progestogen-only method is likely to be the safest. FSRH guidance therefore extrapolates from observational general population data, which suggests that all progestogen-only methods may increase the risk of breast cancer slightly (fsrh-cadbc-guidance-document-15-nov-2023.pdf).

When discussing the best option with a patient, we should consider: 

• Medical history and patient characteristics (e.g. age, weight) that may impact medical eligibility.
• Drug interactions that may impact the efficacy of oral and subdermal progestogenic contraception.
• The importance of a highly-effective method if a patient is on a teratogen.

(fsrh-cadbc-guidance-document-15-nov-2023.pdf)

It would seem to make sense that a low-dose preparation such as the IUS would be safer than higher-dose progestogenic methods. Moreover, for women on tamoxifen who may be at increased risk of endometrial cancer, an IUS would potentially reduce endometrial risk. However:

• There is no evidence to support the safety of the IUS over other methods.
• A number of studies have looked at IUS use in women with a history of breast cancer, but they were all too small to reach definitive conclusions regarding breast cancer outcomes.
• A Cochrane review of 4 randomised controlled trials involving 567 women found that the IUS reduced the risk of endometrial cancer in women on tamoxifen, but the IUS is not currently licensed to be used in this scenario   (Levonorgestrel intrauterine system for endometrial protection in women on adjuvant tamoxifen Cochrane database Syst Review 2020).

• Combined hormonal contraception should be avoided after any breast cancer due to the potential increased risk of thrombosis as well as breast cancer recurrence.
• The FSRH points out that even women with oestrogen-negative tumours may have higher-than-background risk of a new primary cancer with use of hormonal contraception, although the evidence for this is not strong. It comments that pragmatic decisions may need to be taken based on risks/benefits.
• There is a large body of observational data from general population studies which suggests that CHC is associated with a slight increased risk of breast cancer while taking the method and for up to 10y after stopping.
• Studies looking at HRT use in menopausal women show increased risk of breast cancer in combined HRT users, which may be extrapolated as evidence of harm from exogenous hormones.   
• Breast cancer and its treatment is associated with increased risk of VTE, as is CHC use. FSRH guidelines therefore recommend that women with a history of breast cancer avoid CHC. 
• Women on a breast cancer treatment which works by suppressing endogenous oestrogen production (e.g. an aromatase inhibitor) should not take CHC because this would negate the therapeutic effect.

The FSRH states:

• The copper IUD should be first-line emergency contraception due to its efficacy and non-hormonal nature.
• If an IUD is not appropriate, either ulipristal acetate or levonorgestrel oral emergency contraception may be given (see article on Emergency contraception for more information).

There is no evidence looking at the safety of emergency contraception in women with a history of breast cancer, but the FSRH regards a one-off dose of an oral hormonal emergency contraception as unlikely to be harmful, and any potential risks likely to be outweighed by the benefit of unplanned pregnancy prevention.

However, the UKMEC includes the statement:  “Frequently repeated UPA and LNG use may be harmful for women with conditions classified as Category 2, 3 or 4 for CHC or POC use”.

Other malignancies can also impact contraceptive choice. Generally, the FSRH assigns a higher UKMEC category when there may be theoretical concerns that hormonal contraception could affect prognosis or progression of disease, although pregnancy would generally be associated with higher risks.

(Note: 1 = no restriction to use, 2 = benefits usually outweigh risks, 3 = risks usually outweigh benefits, 4 = absolute contraindication)

(UKMEC April 2016 Summary Sheet (Amended September 2019)

Contraception following a diagnosis of breast or other cancers Breast cancer is the commonest cancer in women of reproductive age, and pregnancy should generally be avoided during, and probably for at least 2 years after, breast cancer treatment. Medical treatments for breast cancer may cause amenorrhoea, but do not provide contraception, nor mean that a woman is no longer fertile. The FSRH recommends a copper IUD or sterilisation as first-line contraception methods in women with a history of breast cancer. Hormonal contraception should generally be avoided in breast cancer unless there are compelling reasons to use it, but combined hormonal contraception should not be used. There are no restrictions on emergency contraception use in women with a history of breast cancer. For other cancers, the FSRH acknowledges a lack of evidence, and suggests a cautious approach based on evidence available and theoretical concerns.

Useful resources: Websites (all resources are hyperlinked for ease of use in Red Whale Knowledge) FSRH - UKMEC