For the first time in decades, researchers are reporting a significant drop worldwide in t

he number of women dying each year from pregnancy and childbirth, to about 342,900 in 2008 from 526,300 in 1980.

The findings, published in the medical journal The Lancet, challenge the prevailing view of maternal mortality as an intractable problem that has defied every effort to solve it. "The overall message, for the first time in a generation, is one of persistent and welcome progress," the journal's editor, Dr. Richard Horton, wrote in a comment accompanying the article, published online on Monday. The study cited a number of reasons for the improvement: lower pregnancy rates in some countries; higher income, which improves nutrition and access to health care; more education for women; and the increasing availability of "skilled attendants"—people with some medical training—to help women give birth. Improvements in large countries like India and China helped to drive down the overall death rates.

But some advocates for women's health tried to pressure The Lancet into delaying publication of the new findings, fearing that good news would detract from the urgency of their cause, Dr. Horton said in a telephone interview. "I think this is one of those instances when science and advocacy can conflict," he said. Dr. Horton said the advocates, whom he declined to name, wanted the new information held and released only after certain meetings about maternal and child health had already taken place. He said the meetings included one at the United Nations this week, and another to be held in Washington in June, where advocates hope to win support for more foreign aid for maternal health from Secretary of State Hillary Rodham Clinton. Other meetings of concern to the advocates are the Pacific Health Summit in June, and the United Nations General Assembly meeting in December.

"People who have spent many years committed to the issue of maternal health were understandably worried that these figures could divert attention from an issue that they care passionately about," Dr. Horton said. "But my feeling is that they are misguided in their view that this would be damaging. My view is that actually these numbers help their cause, not hinder it. " He said the new study was based on more and better data, and more sophisticated statistical methods than were used in a previous analysis by a different research team that estimated more deaths, 535,900 in 2005. The authors of the earlier analysis, published in The Lancet, in 2007, included researchers from Unicef, Harvard, the World Bank, the World Health Organization and the Johns Hopkins School of Public Health. The World Health Organization still reports about half a million maternal deaths a year, but is expected to issue new statistics of its own this year.

The new report comes from the University of Washington and the University of Queensland in Brisbane, Australia, and was paid for by the Bill and Melinda Gates Foundation. A spokesman for Unicef said it had no comment on the new findings, and there was no response to messages that were left late Tuesday for W. H. O. officials. Dr. Christopher J. L. Murray, the director of the institute for health metrics and evaluation at the University of Washington, in Seattle, and an author of the study, said, "There has been a perception of no progress. " But, he said, "some of the policies and programs pursued may be having an effect. " "It really is an important positive finding for global health," he said. Dr. Murray said no one had approached him directly about delaying the release of his findings; he heard about those efforts from The Lancet, and described them as "disappointing". He said, "We believe in the process of peer-reviewed science, and it's the proper way to pursue these sorts of studies. "

The most suitable substitute for "defied" in Paragraph 2 is______.

A．resisted

B．eluded

C．challenged

D．denied