Abortion opponents got a morale boost from the Bush administration Thursday when Health and Human Services Secretary Tommy Thompson announced that fetuses would henceforth be redesignated as "unborn children."

The immediate purpose of the reclassification was to give low-income women access to prenatal care, but the change would allow abortion opponents to more forcefully make their case that prenatal children should be afforded the same rights as their postnatal counterparts.

Under the new classification, pregnant women will be able to take advantage of states' versions of the Children's Health Insurance Program, originally intended for children only. Currently, states must get permission from HHS in order to give mothers access to the CHIP program.

Thompson regularly allows the waivers, but said changing the fetuses' status will streamline the process, allowing quicker access to vital prenatal care that would significantly increase the health of children later in life.

"Prenatal care for women and their babies is a crucial part of the medical care every person should have through the course of their life cycle," Thompson said. "Prenatal services can be a vital, lifelong determinant of health, and we should do everything we can to make this care available for all pregnant women."

The policy change, which will not take effect until public comment is received and the regulation is printed in the Federal Register, has been under consideration since last summer.

Thompson decided not to wait for legislation, pending in the Senate, that would have allowed states to add pregnant women to CHIP without seeking HHS approval.

The decision has already put abortion-rights supporters up in arms. They say other ways are available to provide health-care coverage to pregnant women without creating what they say is a back-door attempt to criminalize abortion.

"If they're interested in covering pregnant women, why don't they talk about pregnant women?" asked Laurie Rubiner of the National Partnership for Women and Families. "I just have to believe their hidden agenda is to extend personhood to a fetus."

This plan "sets legal precedent on its head," she added.

Abortion opponents, however, welcomed the news.

"It is something that we endorse and have been working to see that it come about," said Kristen Hansen, a spokeswoman for the Family Research Council. "It's something we're very happy about. This does acknowledge that low-income pregnant women need help with prenatal care."

The National Governors Association has already cautioned Thompson that some states may face divisive battles over adding pregnant mothers to CHIP. Many others, however, will embrace the new option and quickly implement it, the association said.

The Associated Press contributed to this report.