Only 14 percent of obstetricians and gynecologists in the United States provide abortions, according to a new survey by researchers at the University of Chicago and Duke University. That is down from 22 percent when a similar survey was conducted in 2008.

The researchers sent surveys to 1,800 doctors, of whom 1,144 responded. Almost all of the respondents (97 percent) said they had had patients ask them for an abortion, but only one in seven would actually perform the procedure. The survey did not say whether the doctors who did not perform abortions were willing to refer patients to doctors who did, although a similar study by the University of Chicago in 2007 found that more than half opposed abortion and at least 14 percent did not believe they were obligated to refer women to abortion providers or to inform them of all their options, in spite of the Supreme Court's Roe v. Wade precedent.

The survey also showed strong demographic trends that distinguished doctors who performed abortions from those who did not. Female doctors were more likely to provide abortions than male doctors, young doctors more likely than older ones, doctors in the Northeast and West regions more likely than those in the South or the Midwest and urban doctors more likely than rural ones. These patterns fit with demographic trends in political orientation: that is, demographics associated with higher levels of conservatism were also associated with less willingness to perform abortions.

Religion was also a key factor in the survey. A full 40.2 percent of Jewish doctors and 26.5 percent of non-religious doctors said they provided abortions. This was in stark contrast to Christian doctors, for whom the numbers ranged from 1.2 to 10.1 percent depending on whether they were Catholic, evangelical Protestant or non-evangelical Protestant.

These findings indicate a substantial lack of access to abortion, particularly in certain parts of the country. It is especially difficult for women to get abortions if they live in rural areas, because if one doctor refuses to perform the procedure, there may not be another doctor nearby. In Kansas, for example, there are only three abortion clinics, two of which will be shut down if regulations announced earlier this year take effect.

This dearth of providers can amount to a de facto ban on abortions even though they are legal. Access to abortion remains limited by the willingness of physicians to provide abortion services, lead author Debra Stulberg wrote in the September issue of the Obstetrics & Gynecology medical journal, as quoted by MedPage Today.

Steven Ertelt, a writer for LifeNews.com, an anti-abortion Web site, argued exactly that. Fewer doctors are willing to perform abortions than before -- creating a situation where the lower availability of abortion may be helping to reduce abortions, he wrote.