George Washington, the father of his country but never the actual father of a child with his wife, Martha, was probably infertile, according to an article in the March issue of the medical journal Sterility and Fertility.

Like most men of his era, the first president blamed his wife for the couple's inability to have a child. But the most likely cause was a tuberculosis infection that Washington contracted before his marriage, according to the article's author, John K. Amory, an assistant professor here at the University of Washington School of Medicine.

Tuberculosis probably caused a testicular blockage that gave Washington a kind of nonsurgical vasectomy, said Amory, a specialist in male reproduction.

If George and Martha were alive today, the doctor said, they would be excellent candidates for an assisted reproduction technique that surgically extracts sperm cells and injects one into an awaiting egg.

Several biographers and historians who specialize in Washington's life said that Amory's theory is consistent with the relatively thin historical evidence about Washington's early years. They said, too, that the theory could become a useful footnote in future accounts of George and Martha's marriage.

"It is certainly something that ought to be taken into consideration," said Philander D. Chase, senior editor of the papers of George Washington at the University of Virginia.

Historians and physicians have long speculated that illness could have been a factor in Washington's childlessness. Various biographies and monographs have mentioned tuberculosis, smallpox, malaria and even Klinefelter's syndrome, a genetic disorder that typically causes men to be tall, clumsy and sterile. Washington was indeed tall, but hardly clumsy.

Amory argues, though, that tuberculosis makes the most medical and historical sense. At the University of Virginia, Chase said that Amory "may well be right."

Several members of Washington's immediate and extended family had tuberculosis, Chase said. It killed his older brother, Lawrence, with whom Washington was close and spent a great deal of time.

The form of the disease that Washington probably had was tuberculous epididymitis, Amory said. It can block a passageway in the back of each testicle, where millions of sperm accumulate before ejaculation.

"My hypothesis is that Washington's sperm were fine," Amory said. "But they were stopped from traveling upstream by the blocked epididymis." While agreeing that Amory's theory does not step on known historical fact, some Washington biographers are less than eager to accept the latter-day speculation of a Seattle reproductive specialist over the contemporaneous conviction of the Founding Father himself.

In a diary entry written when he was 54, Washington made it clear that he thought he had what it takes to father children. If Martha were to die before he did, he wrote, he believed he was capable of having children by a younger wife -- although he added that he would only marry "a woman of an age suitable to my own."

"In Washington's mind, at least, there is the idea that he could father a child," said Willard Sterne Randall, historical scholar in residence at Champlain College in Burlington, Vt., and author of "George Washington: A Life."

"If a virile man who can ride a horse 20 miles a day thinks he can still do it, do we listen to him or to a medical expert 200 years later?" Randall asked.

Randall is among many historians who say that the likely cause for the Washingtons' inability to have children belonged with Martha. She was known to have had a severe bout of measles shortly after their marriage in 1759, when both were 27 years old.

"I don't think it is George," Randall said. "I think it is Martha."

But Amory says there is little scientific association between measles in adulthood and female infertility. He also points out that Martha had a very strong track record of fecundity. A young widow when she married Washington, she had had four children in eight years in her previous marriage.

"Furthermore, no evidence exists that her last pregnancy was complicated by post-partum infection or hemorrhage . . . that might have made additional pregnancies impossible," Amory writes in the article.

Washington, by contrast, had had years of serious illness before his marriage. He came into close contact with tuberculosis at age 19 when he was in Barbados with his ailing brother Lawrence, who had traveled to the island for his health but soon died of the disease.

Over the next several years, while fighting in the French and Indian War, Washington had chronic fevers, stomach pain and regular bouts of bloody diarrhea. Amory says that strongly suggests gastrointestinal tuberculosis, which he speculates had spread to Washington's genitals before his marriage.

A local doctor warned Washington in 1757 that he had symptoms of the "decay," then the term for tuberculosis. That year Washington wrote, "My constitution is certainly impaired . . . nothing can retrieve my health but the greatest care."

Washington, of course, did recover and went on to marry Martha, command American forces in the Revolutionary War, serve two terms as the new nation's first president and retire voluntarily to Mount Vernon, his family home in Virginia.

Whatever the biological reason for his inability to father an heir, many historians say that the fact of his childlessness -- a biographical detail well known to Americans of his era -- was a key to his legacy and to the early stability of the United States.

"Many Americans were worried about monarchical succession, and it was very important to them that Washington be childless," said Susan Dunn, a professor of humanities at Williams College and co-author with James MacGregor Burns of "George Washington." The new biography is part of a series on U.S. presidents.

Dunn said that Washington, because he had no children and because he shunned the trappings of monarchy, was elevated in American mythology to the role of father of the country.

Washington himself sensed the mythical value of not having an heir, Dunn said.

"I have no child, no family to build in greatness upon my country's ruins," he wrote in a draft of his first inaugural address.

When Washington died, one of the orators at his funeral said, "Americans! He had no child -- but you."

Here in Seattle, Amory was asked what prompted him to speculate about George and Martha's barren marital bed.

"I am a history buff," he said. "I was reading a biography of Washington, and I tend to think about people's reproductive lives a little bit more than most."

Historians and doctors have long speculated that illness was the reason for George Washington's childlessness. Martha Washington bore four children during a previous marriage, but George Washington blamed her for the couple's inability to have a child.