Women who have sex with women

Overview

Current evidence indicates that cisgender women who have sex with women have the same rate of sexually transmitted infections (STIs) as heterosexual women, however the prevalence of particular STIs differs between these groups.
Women who have sex with women are often presumed to be at low or no risk for STIs based on sexual orientation, including being refused screening in some cases, which can cause distrust of health care and poor health outcomes.
Women who have sex with women may be cisgender or transgender, and may have internal or external genitals, and use them in a variety of ways. It is important not to assume that women who have sex with women means 2 people with vaginas and uteruses.
Few data are available on the risk for STIs transmitted by sex between women, but risk probably varies by the specific STI and sexual practice (e.g. oral-genital sex; vaginal or anal sex using hands, fingers, or penetrative sex toys; and oral-anal sex).
Women who have sex with women are at risk for acquiring bacterial, viral and protozoal infections from current and prior partners, both men and women. Up to 90% of this group of women have had or continue to have sexual partners who are men.
Prevalence of bacterial vaginosis estimates are significantly higher for women who have sex with women (20-50%) than exclusively heterosexual women.

Infection	Consideration
Chlamydia	Women-to-women transmission uncommon
Gonorrhoea	Women-to-women transmission uncommon
Trichomoniasis	Test if symptomatic
Bacterial vaginosis	Test if symptomatic
Hepatitis B	Vaccinate if not immune as per state and territory guidelines.
Syphilis	Consider window period and history No data available on women-to-women transmission. All sex partners should be tested if positive.
HIV	Consider window period (45 days) and history Women-to-women transmission uncommon. All sex partners should be tested if positive.

Investigations and clinical indicators for testing

Women who have sex with women are a diverse group with variations in sexual identity, gender presumed at birth, sexual behaviours, sexual practices and risk behaviours. Testing of these women will depend on the history, the clinical picture and risk factors identified.
Routine cervical cancer screening should be offered to all people with a cervix and they should be offered the human papillomavirus (HPV) vaccine in accordance with current guidelines.
It is not recommended to routinely test for herpes and genital warts with serology. Consider testing for herpes and genital warts only if there are clinical signs and symptoms.

Special considerations

Trichomoniasis transmission occurs between women, therefore treat partners as well as the patient.
Bacterial vaginosis is highly associated with women who have sex with women and is high in same-gender partnerships. No partner treatment trials have been performed, therefore standard recommendations are that women partners of women with bacterial vaginosis should be offered testing and treatment.
Testing for bacterial vaginosis as part of a preconception screen is encouraged for all women who have sex with women.

If test results are positive, refer to STI management section for advice on:

Even if all test results are negative, use the opportunity to:

Educate about HIV PrEP/PEP, safe injecting practices, consent, CST and vaccinations for HAV, HBV and HPV as indicated.
Vaccinate for hepatitis B, if susceptible
Discuss and activate reminders for regular testing according to risk, especially if their behaviours indicate the need for more frequent testing
Discuss need for cervical cancer screening.

Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep 2021;70:1-187. https://www.cdc.gov/std/treatment-guidelines/STI-Guidelines-2021.pdf (last accessed 18 October 2021).
Melbourne Sexual Health Clinic (2021). Testing Guidelines. https://www.mshc.org.au/health-professionals/testing-guidelines
Marazzo, J. (2002). STD and Genitourinary infections in lesbians: practical and research update, Washington.
McNair R. Lesbian and bisexual women’s sexual health. Aust Fam Physician 2009;38:388 –93.
Knight DA, Jarrett D. Preventive health care for women who have sex with women. Am Fam Physician 2017;95:314-21.