The number of abortions performed in U.S. clinics was lower in 2017 than in any year since abortion became legal nationwide in 1973, new data showed this week. But that does not count a growing number of women who are managing their abortions themselves, without going to a medical office -- often by buying pills illicitly.These "invisible" abortions are hard to measure, so it's unclear how much higher the true abortion rate is. But researchers say self-managed abortions have risen as abortion has become more restricted in certain states, and as more people have learned that effective pills can be ordered online or purchased across the border."This is happening," said Jill Adams, executive director of If/When/How: Lawyering for Reproductive Justice, which provides legal assistance to women seeking abortions. "This is an irreversible part of abortion care here in the United States."The black market for abortion pills has changed the landscape for those lacking easy access to an abortion clinic or preferring to have an abortion in private. The pills are harder to regulate than in-clinic abortions; they can be easily hidden and shipped, and women can take them at home and appear to have had a spontaneous miscarriage."When you say a self-managed abortion, people think about a coat hanger or a back-alley abortion," said Abigail Aiken of the University of Texas at Austin, who has studied the safety of self-managed abortions and the reasons women choose them. "The reality is we're sitting here in 2019, and it's not like that anymore. You can go online, and you can fill out a form, and you can get this safe and effective technology delivered to your home."Some anti-abortion groups expressed alarm. "The industry's migration to chemical self-abortion is deeply disturbing as it carries with it the possibility of increasing the overall abortion rate over time," Chuck Donovan, president of the Charlotte Lozier Institute, said in a statement this week.Experts disagree somewhat about how many such abortions are occurring in the United States. Some estimated a few thousand a year; others said tens of thousands. Because they are underground, it's hard to measure them precisely. Those numbers compare with around 862,000 in-clinic abortions in the new yearly count published this week by the Guttmacher Institute, which collects the most detailed statistics about abortion in this country, and supports abortion rights."I have no doubt that it will become more common if access becomes more constrained," said Daniel Grossman, a physician and a professor of obstetrics and gynecology at the University of California, San Francisco, who has studied self-managed abortion overseas and in the United States.The current abortion pill regimen, approved by the Food and Drug Administration in 2000, involves two medications. The first, mifepristone, blocks pregnancy-enabling hormones. The second, misoprostol, causes uterine contractions. Between 2014 and 2017, there was a 25% increase in the share of in-clinic abortions by medication instead of by surgery, found the Guttmacher report. They were 39% of abortions in 2017.Mifepristone is tightly monitored in the United States, and is usually administered in a clinic by a certified doctor. But misoprostol, originally developed as an ulcer drug, can be easier to obtain. It is sold over the counter in many countries, including Mexico.When both pills are used for pregnancies of up to 10 weeks, the pills are 98% effective. When misoprostol is taken alone, it is around 80% effective. Aiken's research on self-managed abortions in Ireland found that widespread use of mail-order pills was as safe and effective as the use of pills administered in a doctor's office. A small percentage of women developed bleeding or infections that required follow-up medical care.Aid Access, a service started by a Dutch doctor, offers online counseling with a doctor along with mail-order abortion pills; it entered the United States last year. Other websites also ship the pills to the United States. A study last year in the journal Contraception and (separately) a New York Times columnist tested pills from online vendors and found that the drugs were real.The people least likely to have easy, affordable access to an abortion clinic tend to be poor and live in states that have restricted abortion. For them, traveling to the nearest clinic can seem insurmountable.But there's evidence that even some people with easy access to a clinic are buying and taking pills on their own, for reasons like privacy or cost. Aid Access requests a $90 donation for the pills and medical counseling. Other sites charge around $200 for the medications. A typical clinic-based medication abortion costs around $500, according to Guttmacher, and is only sometimes covered by health insurance.Awareness of the option appears to be spreading, as women share their experiences on Reddit and other online forums. Proponents have started sites explaining how to get the pills -- and the medical and legal issues involved.The new Guttmacher report found that in-clinic abortions declined by 7% between 2014 and 2017, and cited increased use of contraception as a major reason. Rachel Jones, a physician and the lead Guttmacher researcher on this week's report, said she thought self-managed abortions were still fairly marginal, but the report mentioned them as a factor for the first time. Other experts said they might be common enough to erase some of the recent measured reduction.In a 2017 editorial in the American Journal of Public Health, Diana Greene Foster, a professor at the University of California, San Francisco, said the leading explanations for the drop in abortions -- better contraception, less sexual activity among young people, and legal restrictions -- didn't suffice. Women using the most effective forms of contraception, she noted, seemed to come from different demographic subgroups than the groups with the biggest abortion declines."The total number of abortions may not be decreasing if women are looking outside the medical system to terminate their pregnancies," she wrote.Researchers have tried various ways to measure the practice. They've surveyed women about their experiences with self-managed abortions. They've counted the sales of abortion pills from Aid Access. And some have looked at related questions, like the frequency of abortion-related web searches.Survey research found that around 1% of women at abortion clinics had tried to end a pregnancy with misoprostol. A broader survey of Texas women found that between 2-4% had attempted to perform an abortion on themselves, though sometimes with other, less effective methods.Aid Access reported 21,000 requests for medications for self-induced abortions last year, in its first year in the country. Other vendors don't report sales figures. Plan C, which provides information about self-managed medication abortions, reports about 40,000 online visitors a month.There is also suggestive evidence from Texas, where a law (since overturned) temporarily imposed strict abortion restrictions. In-clinic abortion rates declined statewide, but fell more sharply close to the Mexican border. It's an indication, researchers said, that people were probably buying pills in Mexico or ones brought across the border instead of driving hundreds of miles to a clinic.This article originally appeared in The New York Times.(C) 2019 The New York Times Company Click here to read full news..