Short for human papillomavirus, HPV is an infection that can be transmitted sexually. There are more than 100 different strains of HPV; of those, about 40 are spread during sex and of those, about 15 can cause changes to cells in the cervix (the lower part of the uterus) that may lead to cervical cancer.
HPV is so common that up to 75 percent of women will contract it by age 50, says Bradley J. Monk, MD, an associate professor in the division of gynecologic oncology at the University of California Irvine School of Medicine. According to research from the University of Washington, HPV is so widespread that having even one sexual partner significantly raises your risk of contracting it. Almost 30 percent of women tested positive for HPV within a year of having sex with their first partner, the study showed.
Most people never know they have HPV, says Dr. Monk, because it is usually symptomless (a couple of strains may cause genital warts) and our bodies can easily fight off the infection over time. HPV can live in the body undetected for years without causing any side effects. But if the virus doesn't go away on its own (which is more likely as you get older or if you have a weakened immune system), HPV can cause changes to the cells of the cervix, which may show up as abnormal results during a Pap smear.
Right now, experts don't recommend getting tested for just HPV because the virus is so common – and usually harmless – and because simply knowing you have it isn't all that helpful. Most women only learn they have HPV after they've received abnormal Pap results (a sign your body hasn't fought off the virus). It's becoming more common to do simultaneous Pap and HPV testing now, says Dr. Monk – so if your Pap turns up abnormal, the sample can then be screened for HPV without requiring an additional sample (and trek back to the doctor) from you. However, not all labs do this automatically, so you should check with your doctor's office to be sure yours does.
Abnormal Pap results can mean a number of things, so don't panic. First, know that between five and 10 percent of women who get yearly Paps will have abnormal results at some point. Sometimes, this is just because of a hard-to-read sample or because of another condition (like a recent yeast infection) that makes the results unclear. Even having sex, douching, or getting tested during or soon after your period can sometimes throw off results. In these cases, your doctor would likely just repeat the test.
If you have an abnormal Pap and test positive for HPV, your doctor will likely perform a colposcopy to learn more about the severity of the changes in your cervix. This procedure involves using a telescope-like tool to examine the cervix and to remove a small sample of cells to be biopsied in lab. From there, your doctor will have a better understanding of what kind of treatment, if any, you'll need.
Thankfully, having an abnormal Pap smear doesn't necessarily mean you'll get cervical cancer. "There's a huge spectrum here – from merely contracting HPV to actually getting cervical cancer, which is very, very rare, comparatively speaking," says Dr. Monk. Here's some perspective:
Of all the millions of women who become infected with HPV, only about 10 percent will get a chronic infection their immune systems can't fight off.
Only a tiny fraction of those – maybe one in 100 – will get precancerous lesions (abnormal cells that could turn into cancer if left untreated).
Of women with precancerous lesions, there are three basic levels of abnormalities. Most doctors won't even treat the first, mildest level because the abnormal cells usually go away on their own.
Treating the second two levels promptly usually means the abnormalities won't have the chance to progress into full-blown cancer. Cervical cancer is pretty rare, and usually only affects women who don't get Pap smears or see their doctor regularly.
Treatment depends on a few things, including your age and the severity of the changes. With mild cases, most doctors adopt a wait-and-see approach with more frequent Pap smears and colposcopies to make sure your body's healing and not getting worse. Women with more serious cases have the following options to consider:
LEEP: An office procedure that uses an electric current to remove the abnormal cells from the cervix.
Cone biopsy: A procedure in which a cone-shaped portion of the cervix (one that contains the precancerous cells) is removed. This is typically performed in a hospital or outpatient clinic under anesthesia.
Freezing and laser: Called cryotherapy, this office procedure freezes the abnormal cells, which are then shed naturally.
The HPV virus alone shouldn't have a huge impact on fertility. Although one study found that IVF patients who screened positive for HPV were less likely to become pregnant than those who tested negative, it's not exactly clear why. Researchers speculate that an embryo may have a harder time implanting in a woman whose immune system is unable to clear the virus – but bear in mind that the vast majority of people with HPV fight it off shortly after contracting it.
However, being treated for precancerous cells may slightly raise your risk for problems conceiving. Procedures like cryotherapy, LEEP, and cone biopsy may narrow the cervix and change the consistency of your cervical mucus, both of which can slow sperm down and make it harder for them to reach and fertilize your egg. Even so, your overall risk of experiencing infertility is very low, says Dr. Monk. Though no studies have researched this area specifically, he estimates that these procedures might impact your ability to get pregnant by less than 5 percent. You'll likely be advised to avoid sex for a month or so after having any of these procedures though, which could postpone conception.
Simply having the HPV virus in your system shouldn't impact your pregnancy in most cases – and your baby won't contract it. If you have genital warts caused by HPV, your doctor may watch you more closely, though women with this condition usually have healthy pregnancies and can even deliver vaginally.
However, treatments like LEEP or cone biopsy for precancerous cells can increase your chances of miscarriage or preterm birth, says Dr. Monk. These procedures raise your risk of cervical incompetence, where your cervix dilates too early. But your doctor can monitor your cervix through ultrasounds. He or she may recommend going on bed rest or a cerclage, a stitch that makes the cervix stronger, to prevent this from happening.
The HPV vaccine is currently recommended for girls and women age 9 to 26, though the Federal Drug Administration (FDA) is considering extending the range up to age 44. If you're older than 26, you can still get the shots, but you'll have to pay out of pocket for them.
The HPV vaccine has proven extremely effective at reducing HPV infection and, consequently, abnormal Pap results. A new study from the University of Alabama at Birmingham found that girls and women who received the vaccine were more than 40 percent less likely to have abnormal Pap results than those who were not vaccinated.
The HPV vaccine protects against four of the most serious strains of HPV – the two that cause cervical cancer and two that cause genital warts. "But even if you've had abnormal Paps or tested positive for HPV, it's still a good idea to get vaccinated, because there's no way of knowing which strains you actually have," says Dr. Monk.
Getting the HPV vaccine doesn't completely eliminate your risk of getting cervical cancer, however. The vaccine protects against two strains that cause about 70 percent of cervical cancers, so even if you're vaccinated, you can still contract other types – and you still need regular Pap screenings.