The same pediatrician who gave your baby her first check-up may soon be giving her advice on how to safely get a tattoo or nose ring.

The American Academy of Pediatrics on Monday issued its first guidelines on "body modifications," acknowledging that invasive body art - once used to mark criminals and slaves in America - has gone mainstream. Nearly 40 percent of millennials have tattoos, and the U.S. Armed Forces has relaxed its restrictions on tattoos in recent years.

Despite the growing acceptance of tattoos and piercings, the academy has been silent about the practice. Now it says that physicians should talk to adolescents about the importance of hygiene at piercing studios and tattoo parlors, even though in most states, it's illegal for a minor to get a tattoo without a parent's permission.

But the guidelines don't mean the group is endorsing the practice.

The report, published in the journal Pediatrics, notes that medical complications can occur and that body modifications "may also co-occur with high-risk behaviors" among adolescents. The pediatricians urge adolescents to talk with their parents, guardians or another "responsible adult" before making the decision to get a tattoo.

Young people should know that "tattoos are permanent and that removal is difficult, expensive and only partially effective," their report said.

Since most people with tattoos say they don't regret getting them, the prospect of a future expensive and painful removal is unlikely to deter a young person intent on etching a rose or skull, among the most popular body art this year, onto a shoulder.

But that's not all they should know, and there's no need to wait for the next doctor's visit. When talking to teens and college students about tattoos, here are other issues that parents might want to point out.

Why hygiene matters

The Food and Drug Administration considers tattoo ink a cosmetic, albeit one that is applied with needles that puncture the skin. Most tattoo artists use a machine that injects ink into the dermis, the second layer of our skin, by pricking the outer layer (the epidermis) several thousand times a minute.

Ideally, the skin is cleansed with an antiseptic before and after the procedure, and the tattoo should be covered for at least 24 hours, then protected with antibiotic ointment as it heals, the academy's report said. "Tattoos generally take two weeks to heal; sun exposure should be avoided or sunscreen should be used, and swimming, direct shower jets, or soaking in water should be avoided," the authors wrote.

The healing time for pierced flesh varies with the part of the body. Pierced ears can recover in a matter of weeks; a pierced belly button might not heal for nine months, Dr. Cora Breuner, a physician at Seattle Children's Hospital and a co-author of the academy's report, told NPR.

Dirty working conditions or unsterile equipment poses a risk, not only of infection, but of the transmission of HIV, hepatitis B and C, tetanus and other complications.

Each state sets its own regulations for sterilization and sanitation, and many studios are fastidious in adhering to best practices. In California, for example, studio owners register with the state health department, take a yearly course in bloodborne disease and infection control, NPR reported. They also have to show that they've been vaccinated against hepatitis.

Consider the ink

Tattoos may pose a health risk based on what ingredients are used in the dye; the Food and Drug Administration says that some inks have been been found to contain components of printer toner and car ink. The academy also expresses concern that some dyes contain traces of metals, including chromium, cobalt, iron and mercury.

"Although the concentration of metals in tattoo ink is low, metals are emerging as a class of human carcinogens. Cutaneous exposure over a lifetime may result in adverse events," the authors wrote.

The FDA encourages people to report adverse reactions to a variety of consumer products, tattoos among them. Between 2004 and 2016, the agency received 363 reports of infections and persistent allergic reactions associated with tattoos.

Does it honor God?

A Harris Poll in 2016 found that 86 percent of people with tattoos said they didn't regret getting them. When asked why they enjoyed having a tattoo, 30 percent said it made them feel sexier, 21 percent said it made them feel attractive or strong, and 5 percent said it made them feel more athletic, and 16 percent said it made them feel more spiritual.

Some people get Bible verses and crosses tattooed on their arms; quotations are the second most common type of tattoo, after roses.

There's even an Alliance of Christian Tattooers, based in Chandler, Arizona.

Yet not everyone agrees that having a tattoo is something pleasing to God. Some people point to Leviticus 19:28, which says, "You shall not make any cuttings in your flesh for the dead, nor tattoo any marks on you: I am the Lord."

The United Church of Christ says that for Christians it is "better that a person not get tattoos" because of the health risks and the possibility of others judging us because of them.

While tattoos are more widely accepted than in years past, more than a third of human-resource managers say that having a visible tattoo can limit someone's career, Business Insider reported last year.

And the pediatricians' report cited an earlier survey in which 76 percent of 2,700 people with a tattoo or piercing thought it hurt their chances of getting a job.

Think before you ink

Although tattoo removal is possible, the process is complicated and expensive. But some people are so desperate to remove old tattoos that they'll go through it anyway.

The American Society of Aesthetic Plastic Surgery says more than 52,000 people had tattoos removed last year, up 13 percent from the previous year, The Chicago Tribune reported. The average session costs $463 and it can take several sessions to remove a tattoo, Kate Thayer reported for The Tribune.

In its new guidelines, the academy notes that there is no comprehensive reporting of medical complications caused by tattoos and body piercings, and in light of the number of people who have them - an estimated 30 percent of Americans have at least one tattoo - the number is likely relatively low.

Problems are most likely to occur if the piercing or tattooing is done at an unlicensed facility. Even at licensed facilities, people should observe a procedure to ensure that best practices are followed. For example, "The piercer should be observed putting on new, disposable gloves and removing new equipment from a sterile container," the academy report said.

At tattoo studios, check to see that fresh, unused ink is poured into a new, disposable container with each client.

And both parents and pediatricians should remind young people that not everyone may love their tattoo as much as they do - including their own future selves.