Editor’s Note: This story has been updated to reflect the latest statistics.

It’s shocking but true: One of the hot trends in plastic surgery right now is labiaplasty, a procedure to trim the vulva's inner lips, aka the labia minora. (Add this to the list of things you shouldn’t do to your vagina.) According to statistics from the American Society of Plastic Surgeons (ASPS), labiaplasty procedures spiked 39% in 2016, with more than 12,000 procedures.

“I am asked about labiaplasty at least once a month,” says ob-gyn Jennifer Gunter, MD, who runs a specialty clinic for vulvar conditions at Kaiser Permanente in San Francisco. “Five years ago, I was probably asked one to two times a year.”

What’s behind this craze? Here’s a look at the facts.

RELATED: Everything You Ever Wanted to Know About Your Vagina

Why the rise?

Michael Edwards, MD, a former president of the American Society for Aesthetic Plastic Surgery, told Time that some women with more pronounced labia are “devastated.” Another plastic surgeon, Richard Swift, MD, on Manhattan’s Upper East Side, told the New York Post, that women “whose labia are enlarged” feel uncomfortable in yoga pants.

But “normal” labia minora come in all shapes and sizes, ranging from 2 to 10 cm in length and 0.7 to 5 cm in width, per a study published in the journal BJOG (images NSFW). And it’s quite common for the labia minora to stick out past the outer lips of the vagina, according to Dr. Gunter, without any discomfort.

In a blog post about labiaplasty (also NSFW), she noted that smaller labia seem to have become the cultural norm, perhaps because many female performers in the adult film industry have small labia. “Whether this is a self-selecting feature or the result of surgery is hard to know,” Dr. Gunter wrote. But “if you see a lot of images of small labia minora you are more likely to come to view that as … desirable.”

[brightcove:5159289060001 default]

How pubic hair trends also play a role

“There is an expression for men, ‘The shorter the bush, the taller the tree,’” and a similar visual effect happens with female genitalia, says Dr. Gunter. “If you remove your pubic hair or trim it significantly, you may start to notice your labia minora.”

In fact, the rise in labiaplasty has been linked to the popularity of the Brazilian wax. As Barbara Levy, MD, the VP of Health Policy at the American Congress of Obstetricians and Gynecologists, put it to NBC News, the hairless trend made women more aware of their genital appearance, and plastic surgeons saw dollar signs.

Do larger labia really cause any symptoms?

The vagina’s smaller, inner folds of skin have an important job: They protect the vaginal opening—called the vestibule—which is made up of delicate mucosa tissue, filled with highly-sensitive nerve endings.

Some women blame painful sex on the size of their labia. Others suspect their labia are the source of their yeast infections, or other irritation. Even doctors attribute some of these vulvar symptoms to the size of the labia minora. But there is almost always another cause, Dr. Gunter says. If you have vulvar symptoms, talk to your ob-gyn first—not a plastic surgeon. You might even want to see a vulvar specialist, Dr. Gunter advises.

RELATED: 20 Weird Facts About Sex and Love

Is labiaplasty safe?

A 2014 study found that more than 91% of women who had the surgery felt more satisfied with their genital appearance afterward. But there are no solid figures on complications, and the long-term implications are TBD. “We don’t know how labiaplasty will affect women as they become menopausal, and their tissues start to change,” Dr. Gunter points out.

The bottom line

Dr. Levy summed up the labia-trimming trend like this: “It’s one more body part that we as women are being told to be insecure about.” But that's not to say that no woman should ever consider the procedure. As with any plastic surgery, the best advice is to make sure you're interested in the procedure for you, rather than some outside pressure.

For an awe-inspiring reminder that every woman’s body is different, take a gander at the Great Wall of Vagina. 

The sculpture, by British artist Jamie McCartney, features plaster casts of 400 vulvas, each beautifully unique.