When lawmakers take aim at abortion, they draw on an ever-growing arsenal of restrictions and mandates imposed on women, doctors and clinics.
But do these measures reduce abortions? It's a question with no simple answer.
Abortion providers and abortion-rights advocates say many of the laws -- those requiring ultrasounds, waiting periods and specific types of counseling -- are burdensome and demeaning, but rarely dissuade women who want the procedure.
"The reality is that if a woman has decided that's what right for her, she'll do whatever it takes to get it done," said Peter Brownlie, CEO of Planned Parenthood of Kansas and Mid-Missouri.
However, when the laws boost the cost of an abortion -- and are coupled with bans on any public funding -- there can be a real impact.
"Overall, the informed consent laws have no deterrent effect," said Tracy Weitz, a sociologist at the University of California, San Francisco who has studied the laws.
"But in states where Medicaid doesn't pay for the abortion -- and that gets piled on with the other regulations -- we do think it's having an effect on women's ability to access affordable services," Weitz said. "They really disproportionately hurt people already economically on the edge."
Michael New, a political science professor at the University of Alabama, estimates that bans on use of Medicaid funds have reduced the incidence of abortion by about 8 or 9 percent. The impact of the informed consent laws -- including waiting periods and mandatory counseling -- is less pronounced, New says.
One challenge for researchers is a lack of current data. The most recent national statistics are from 2008, when there were an estimated 1.21 million abortions in the U.S., down from a peak of 1.6 million in 1990.
Scores of bills aimed at deterring abortion have been passed since 2008, mostly by Republican-controlled legislatures and often based on proposals from anti-abortion groups. Last month, Virginia's GOP Gov. Bob McDonnell backed away from a bill requiring women to undergo an invasive vaginal ultrasound prior to abortion after the measure drew protests at the statehouse and ridicule on late night comedy shows. An alternative requiring noninvasive ultrasounds is now headed back to McDonnell, and similar bills are pending in Alabama and Idaho.
Yet amid the outcry over the original Virginia bill, Texas has been enforcing a similar law enacted last year that makes vaginal ultrasound a precondition for many abortions. The law also requires that the women hear their doctors describe the fetus' development during the ultrasound, and then wait 24 hours before undergoing the abortion.
Abortion-rights supporters in Texas doubt that the images and information provided by that process will dissuade many women from having abortions. However, they say the law nonetheless could be a deterrent because of cost factors -- women now need to make two trips to a clinic and will occupy more of their doctors' time.
"The price of the procedure has increased with some of the providers -- and there's the cost to women of taking more time off from work," said Houston attorney Shailey Gupta-Brietzke, who helps oversee the Lilith Fund, a program assisting women who can't afford abortions on their own.
Dr. Curtis Boyd, who operates the Southwestern Women's Surgery Center in Dallas, said the new law has forced him and other abortion providers to raise prices, generally by $50 to $75 per procedure.
Boyd, a full-time abortion provider since the 1970s, said ultrasounds are routinely performed before abortions. But he resents a mandate being imposed by legislators and says his patients -- many of them already mothers -- are unlikely to change their mind due to an ultrasound.
"Women know they're pregnant and it's going to result in the birth of a baby," Boyd said. "That's why they come, because at this time in their life, they don't want to have a baby."
In North Carolina and Oklahoma, laws mandating pre-abortion ultrasounds have been blocked by court challenges, but both states have other restrictions in effect.
Dr. Amy Bryant of Chapel Hill, N.C., said requirements for pre-abortion counseling can be grating in instances where the pregnant woman has been raped or has a fetus with a severe anomaly. Even in such cases, Bryant said, doctors must tell the woman she has the options of keeping the baby and seeking child support from the father.
"It's horrible to have to say those things," Bryant said. "It's medically and emotionally inappropriate."
Abortion opponents counter that many of the state laws provide women with valuable information. They support the requirements in some states that counseling include warnings about risk of breast cancer and mental health problems -- even though major medical organizations dispute those purported links and tout abortion as a safe procedure.
"What we hear, time after time, from women who've had abortions is they were given no information about the risks and long-term consequences," said Dr. Donna Harrison of the American Association of Pro Life Obstetricians and Gynecologists.
"This is an assembly line, get 'em in, get 'em out, moneymaking business," Harrison said. "Someone has to be on the side of the patient. If the doctors aren't doing it, someone else has to do it."
Among the states with pending bills are Florida (24-hour waiting period), Georgia (ban most abortions after five months of pregnancy) and Oklahoma (require doctors to make the sounds of a fetus' heartbeat available to women before an abortion). South Dakota lawmakers want to mandate a longest-in-the-nation 72-hour waiting period and require women to get counseling at crisis-pregnancy centers run by anti-abortion groups.
In Utah, a proposed bill would extend a 24-hour waiting period to 72 hours. Its sponsor, Rep. Steve Eliason, calls it a consumer-protection measure "that gives a person facing a major life decision, a major medical decision, a major financial decision, sufficient time to consider the ramifications."
Mississippi is often cited as proof that restrictive laws can reduce abortions. In the time the state has enacted many restrictions, its abortion rate has dropped to among the lowest in the nation.
The Guttmacher Institute, a research organization that favors abortion rights, says the decline stems in part from Mississippi's law requiring women to get in-person counseling at least 24 hours before an abortion.
There are other factors at play. The state only has one abortion clinic, and a Guttmacher report says there's evidence that many Mississippi women now chose to get abortions in other states.
Looking nationally, Guttmacher says counseling and waiting period laws have limited impact. "By and large, they do not prevent abortions," it says.
The one clear exception, Guttmacher says, are restrictions targeting lower-income women. According to the institute, one in four women who would have had a publicly funded abortion instead will carry an unwanted pregnancy to term because of funding bans.
Dr. Fredrik Broekhuizen, medical director for Planned Parenthood of Wisconsin, said his state's ban on public funding of abortions has been compounded by increasing reluctance of private insurers to cover the procedure.
Americans United for Life, one of the anti-abortion groups advocating for restrictive laws, has made funding bans a key part of its strategy for eroding the nationwide right to abortion established by the Supreme Court's 1973 Roe v. Wade decision.
"Roe is currently being overturned state-by-state, case-by-case," says the group's president, Charmaine Yoest.
Guttmacher Institute summary of state laws: http://bit.ly/QMx6K
American Association of Pro Life Obstetricians and Gynecologists: http://www.aaplog.org/
David Crary can be followed on Twitter at http://twitter.com/CraryAP