Getting regular Pap smears is a necessary evil for all women. Those few minutes of discomfort, legs propped in stirrups, can detect HPV or cervical cancer, which is why it’s recommended you have one every three years. But according to a new review of research published in the journal Nurse Practitioner, lesbian women are not being screened as often as their heterosexual counterparts.

Lesbians comprise between 3%-11% of our country’s female population, but they’re screened at rates 5-18% lower than heterosexual women, the analysis reports. The reason? Well, there are a handful of factors that could contribute.

Until recently, medical professionals thought lesbians were less at risk for contracting HVP, the STI that can cause cervical cancer. That’s because the most common way it’s transmitted is from male to female.

But this particular review found that many lesbians or their partners have had previous sexual experiences with men: In four studies, an average of 77% of lesbians said they’ve had sex with men in the past. Lesbians also reported having more sexual partners than heterosexual women, and having more sex before 18, both of which are considered higher risk factors for HPV.

The research also pointed out is that lesbian and bisexual women are 6% less likely to have health insurance, which could be related to same-sex marriages not being recognized as eligible for shared insurance plans, or because of social and cultural biases that penalize these women economically. And as for women who are insured, they may not be seeing their gynecologists regularly for preventive care if they’re not going for contraception or family planning services. On top of all that, negative experiences with doctors or feeling stigmatized for their sexual orientation could be adding to ladies’ hesitation to schedule their yearly checkup.

It’s important that all women get a Pap smear — every 3 years if you’re 21-65 and have a cervix — regardless of sexual history. You’re your best health advocate, never forget that. So pick up the phone and book your appointment!

Read More: 8 Million Women Haven’t Had a Pap Smear in 5 Years

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