With more and more expectant mothers choosing to deliver by Caesarean section -- one out of every four babies in the United States is now delivered surgically -- maternity wards nationwide are feeling the pinch as women stay longer to recover, putting already stretched space at a premium.

At Inova Fairfax, the nation's sixth-busiest birthing center, mothers spent a total of 1,000 more days in the hospital last year than the year before, even though the number of births declined slightly.

"Capacity issues are becoming problematic," said Bonnie Jellen, director for maternal and child health at the American Hospital Association. "The centers are overcrowded."

The trend has fueled expansion efforts at hospitals across the region, with obstetric facilities being enlarged to include more private rooms and labor and delivery suites.

Caesarean deliveries, unless medically necessary, were largely frowned on in the 1980s and early '90s. That has changed as more information has emerged about the possible consequences of natural childbirth to older mothers and the difficulties encountered by many women attempting a vaginal birth after having delivered a child surgically.

Elective C-sections strictly for convenience's sake are still controversial. But many women who choose the procedure say they want to avoid potential health problems associated with natural childbirth, among them incontinence and pelvic disorders.

Carrie Fischer had a Caesarean four years ago after learning that one of the twins she was carrying was breech. But the decision about whether to deliver her third child naturally was more choice than medical certainty.

After talking it over with her obstetrician and others, Fischer, 33, and her husband, Rob, 36, opted for another C-section. On Thursday, she checked into Inova Fairfax Hospital, where, after 20 minutes in the operating room, 7-pound, 5-ounce Grant Russell Fischer announced his arrival with a piercing wail.

"Hearing about the risks, I didn't want to chance it," Fischer said minutes before the procedure. "Why take a risk?"

While high-risk births do account for much of the traffic at Inova Fairfax -- 11,013 babies were born there last year -- obstetrics chairman Fred Mecklenburg said that Caesarean births also factor into the high number of patients each day.

"Patients who deliver by Caesarean section stay in the hospital longer" to recover, he said. "So in a hospital like Fairfax that has a 36 percent C-section rate and does an average 32 deliveries a day, that means eight of those births are C-section, and there'll be eight more patients in the hospital tomorrow and every day."

The impact is felt across the board, with obstetrical wing expansions, some of them dramatic, in the works at almost every hospital in Northern Virginia.

At Holy Cross Hospital in Silver Spring, which had 7,261 births last year, the second-most in the Washington region, construction is under way to convert all rooms to private occupancy and to increase the number of labor and delivery rooms from 15 to 21 -- needs made more pressing, officials said, by the growing Caesarean rate. Last year's total of 1,999 C-sections was a 42 percent increase over 1998.

In 1995, Anne Arundel Medical Center tripled its number of labor and delivery rooms with a new pavilion. Today the hospital delivers more than 4,600 babies a year -- more than one-fourth of them surgically -- and is the second-largest birthing center in Maryland.

When planners conceived the pavilion in 1992, its design was based on the premise that obstetrical stays were shortening. But in the mid-1990s, state laws governing maternity hospitalization changed, increasing the amount of time mothers could stay from two to four days, depending on the procedure. As a result, the Anne Arundel center has already completed one expansion and is planning a second.

"That's how we've tried to accommodate that continued rise in volume and rise in length of stay," said Karen Peddicord, administrator of the hospital's Women's and Children's Center. "We're fortunate that we planned alternative space we could work with."

From 21 percent to 23 percent of the babies born at Washington Hospital Center are delivered by Caesarean, up from about 16 percent five years ago. But hospital officials say their high maternity numbers are more the result of last year's closure of Columbia Hospital for Women.

Until space is added, hospitals and doctors in the region are coping in various ways.

At Inova Fairfax, where administrators say there is limited capacity to expand, officials are considering scheduling elective C-sections on weekends to create a better patient flow, and are increasing the number of private rooms to make the hospital more comfortable for new mothers.

At Reston Hospital Center, whose massive renovation project should be completed next year, a physicians lounge has been converted into a triage area for mothers waiting to deliver surgically.

"We frequently have more patients than we have beds," said Mandy Milot, director of maternal child health at Reston. "When we get real busy it's like a puzzle: This patient goes here; this one goes here. Just when we have the puzzle figured out, someone else walks in to give birth. . . . I'm thinking that before long we'll have to look down the road [to expansion] again."

Caesareans often were discouraged a generation ago as unnecessary, costly and potentially dangerous. But by 1996, the number of C-sections had started to climb again, which experts say is the result of older women trying to avoid problems sometimes associated with natural childbirth, and the trend away from women attempting natural childbirth after a C-section.

The high cost of malpractice insurance has also played a role, making doctors more cautious about advocating vaginal delivery for some women. In fact, some doctors and hospitals refuse to deliver babies vaginally if the mother has had a C-section, practitioners say.

"People are beginning to realize that the natural process of labor and delivery is fraught with hazard," said Paul Burka, an obstetrician in Reston for 25 years whose practice now focuses on women's general health. "When you stop and think of all the things we used to do to prevent C-sections," he said, "now that seems stupid," given the advances in medicine that have made the procedure less risky.

But crowded maternity wards are frustrating for doctors and patients whose lives are disrupted when a scheduled induction or C-section has to be postponed. Some doctors even advise patients who are not high risk that the best way to avoid having to wait and to guarantee themselves a private room is to steer clear of the busier birthing centers.

Belinda Ramberg did that when she had daughter Madeleine, now 6 months old, at Inova Alexandria Hospital.

"They said go to Alexandria because a lot of times you're in the hallway at [Inova] Fairfax waiting because there are no hospital beds," Ramberg, 30, said. "That scared me."

Both of Paula Light's pregnancies were high-risk. Light, 32, said the care she received after her two Caesareans at Inova Fairfax was first-rate.

The trade-off, she said, was a five-hour wait in triage before she delivered her second child, Aidan, last June. Her procedure was bumped back three times by emergency C-sections, she said. Waiting with her were four other women, each in labor.

"I felt like I was at Disneyland" waiting for a ride, she said. "It was definitely busy there, constant motion."

Toni R. Ardabell, chief operating officer for Inova Fairfax's Women's Center, said the hospital can get jammed after a full week of inductions and C-sections. "Everybody gets a bed," she said, "but you might have to wait."

The hospital added eight private rooms last year and plans to double that this year. Said Ardabell, "We want to make sure if women aren't coming here because they think it's too crowded that we fix that."

Carrie Fischer holds her new son, Grant, in both arms for the first time.Although only a few minutes old, Grant Fisher already shows off loud cries.Carrie Fischer walks to the operating room, followed by nurse Linda Lawrence and Fischer's husband, Rob.As Glenna Andersen, above right, finishes the procedure, Rob and Carrie Fischer spend their first few moments with son Grant at Inova Fairfax Hospital, the nation's sixth-busiest birthing center.Grant Russell Fischer enters the world at 7 pounds, 5 ounces with a healthy cry. His mother, like many others these days, opted for a Caesarean section -- a trend that is causing a space crunch at hospitals in the Washington area and elsewhere. Carrie Fischer gets her first look at her new son. She had considered natural delivery but opted for a Caesarean section. "Hearing about the risks, I didn't want to chance it," she said.