"It's going to be cold, and some pressure, O.K.?"
The medical assistant guided the gelled ultrasound transducer across the pregnant woman's belly. The patient, a 36-year-old divorced woman named Laura, stared straight ahead, away from the grainy image on the screen to her side.
The technician told Laura she was at 11 weeks. "Do you want to see your ultrasound?" she asked. "I'd rather not," Laura answered promptly.
Laura, who asked that her last name not be used, had come to the New Woman All Women Health Care clinic in Birmingham with her mind set on having an abortion. And she felt that seeing the image of her bean-size fetus would only unleash her already hormonal emotions, without changing her mind.
"It just would have added to the pain of what is already a difficult decision," she said later.
Over the last decade, ultrasound has quietly become a new front in the grinding state-by-state battle over abortion. With backing from anti-abortion groups, which argue that sonograms can help persuade women to preserve pregnancies, 20 states have enacted laws that encourage or require the use of ultrasound.
Alabama is one of three states, along with Louisiana and Mississippi, that require abortion providers to conduct an ultrasound and offer women a chance to peer inside the womb.
Late last month, Oklahoma went a step further. Overriding a veto by Gov. Brad Henry, a Democrat, the Republican-controlled Legislature enacted a law mandating that women be presented with an ultrasound image and with a detailed oral description of the embryo or fetus.
A state judge quickly stayed the requirement pending a July hearing in a suit filed by two abortion providers. But the measure has prompted outrage among abortion rights advocates and raised questions about the impact of ultrasound laws.
In one of the few studies of the issue — there have been none in the United States — two abortion clinics in British Columbia found that 73 percent of patients wanted to see an image if offered the chance. Eighty-four percent of the 254 women who viewed sonograms said it did not make the experience more difficult, and none reversed her decision.
That generally has also been the case in Alabama, which enacted its law, the first of its kind in the United States, in 2002.
"About half of women opt to view them," said Diane Derzis, who owns the Birmingham clinic. "And I've never had one patient get off the table because she saw what her fetus looks like."
In some instances, the ultrasounds have affected women in ways not intended by anti-abortion strategists. Because human features may barely be detectable during much of the first trimester, when 9 of 10 abortions are performed, some women find viewing the images reassuring.
"It just looked like a little egg, and I couldn't see arms or legs or a face," said Tiesha, 27, who chose to view her 8-week-old embryo before aborting it at the Birmingham clinic. "It was really the picture of the ultrasound that made me feel it was O.K."
The National Abortion Federation, which sets quality standards for abortion providers, does not require ultrasounds in the first trimester. But many clinics routinely perform them to look for anomalies and to establish a precise gestational age, which can determine the method of extraction.
Abortion rights advocates oppose laws that require ultrasounds, even if viewing the images is voluntary.
"The laws don't work," said Vicki A. Saporta, the federation's president. "They inappropriately interfere with the patient-doctor relationship, and they don't respect women's ability to make informed choices."
The anti-abortion movement has regularly used ultrasonic imagery dating back to "The Silent Scream," the influential 1984 film that depicts an abortion in progress. More recently, Focus on the Family spent an estimated $10 million to buy ultrasound equipment and provide training for centers that steer women away from abortion.
"To be able to put a face on that baby humanizes this process and really allows the mother to connect," said Carrie Gordon Earll, a Focus on the Family spokeswoman. "Ultrasound is one of the ultimate examples of informed consent because you are seeing what you are giving permission to happen."
As with many abortion regulations, state laws regarding ultrasound vary widely. Five states, including two that enacted laws this year, require that abortion providers offer to conduct ultrasounds, according to the Guttmacher Institute, which monitors reproductive health issues. In eight others, providers who perform ultrasounds as a standard practice must offer patients a chance to see them.
Ultrasound bills were introduced in 21 statehouses in 2010, according to the institute. Gov. Charlie Crist of Florida, a Republican, must soon decide whether to sign legislation that would require doctors to perform ultrasounds and show and describe the images to patients unless they sign a refusal.
Oklahoma's new law exempts women who need an abortion for emergency medical reasons. But it does not allow exceptions for victims of rape or incest.
During the six days the law was in effect, all of the patients at the Reproductive Services abortion clinic in Tulsa averted their eyes from the ultrasound screen, said Linda S. Meek, the clinic's director. But they could not avoid hearing descriptions of fetal length and heart activity, she said. Many left in tears, but none changed course.
"It's very intrusive, and very cruel," Ms. Meek said.
The Alabama law has had no apparent impact on the number of abortions, which hovers around 11,300 a year. State law also requires that women receive a pamphlet on fetal development and a directory of adoption agencies during a 24-hour waiting period.
Staff members interviewed at three of the seven abortion clinics in the state estimated that 30 percent to 70 percent of women chose to see ultrasound images. But they said it was uncommon for women to be dissuaded.
It had happened occasionally, they said, when a sonogram revealed a multiple pregnancy or when a woman was already deeply unsure about her choice.
But a number of women at the Birmingham clinic, which was the site of a fatal bombing in 1998, said they simply did not want to subject themselves to images that might haunt them. "You almost have to think of it as an alien," said Carmen, 28, who was there for her second abortion in three years.
Like other patients, Laura, who has a 17-year-old son, said she took offense at the state's implicit suggestion that she had not fully considered her choice.
"You don't just walk into one of these places like you're getting your nails done," she said. "I think we're armed with enough information to make adult decisions without being emotionally tortured."
