Just when you thought the baby boom was over . . . .

More quadruplets were born this week at the University Hospital - the second set delivered in Salt Lake City this year.Starting at 12:27 a.m. Tuesday, Diana Hsu first gave birth to a boy, followed by a girl, followed by another girl and - then for good measure - yet another girl.

Count 'em, four.

The quadruplets, delivered Caesarean section by Dr. Michael Varner, were 12 weeks early. Jeremy Kenneth, Leslie Fan, Sherry Chen and Tiffany Lee - who weighed from 2 pounds 1 ounce to 2 pounds 4 ounces - were all listed in serious condition Friday in the hospital's newborn intensive care unit.

But Varner said the babies are progressing nicely. "They are all appropriate weight for their gestational age, which certainly is helpful in their overall prognosis," he said.

Coincidentally, the Hsus were the second Holladay couple to deliver quads this year. Scott and Sherri Cook's quadruplets were born at LDS Hospital March 15. Both Holladay women were taking clomid, a mild fertility drug prescribed to enhance ovulation. Women taking the drug frequently have twins; quads are rare.

It was the second set of quads delivered at the U. Hospital. An Idaho woman, participating in the in-vitro fertilization program, gave birth to four babies last year.

To ensure the safe arrival of the Hsu quads, Diana was hospitalized 15 weeks ago while "Daddy Ken" - with help from relatives - cared for the couple's three other children - Julie, 8; Lisa, 7; and Stacy, 4. Last week Diana was given medication to prevent premature labor.

But Tuesday, the babies defied mom and medicine by announcing their eagerness to come into the world.

Immediately upon delivery, surfactant, a protein taken from calves' lungs, was administered to keep the small air sacs in the babies' lungs open, enabling them to get enough life-saving oxygen.

The U. Hospital is one of only eight facilities in the country approved by the federal Food and Drug Administration to administer this breakthrough drug.

"It's by far the single largest advancement in terms of perinatal care and quality perinatal survival," Varner said. "By far the most significant problem with premature babies is respiratory distress syndrome - immature lungs. Ten years ago the survival rate for babies this size was 10-20 percent.

"Last year it increased to between 80 and 90 percent. The drug has made a major dif-ference."

Though optimistic, Diana and Ken fully realize that their children aren't out of the woods - yet.

"It's overwhelming to go into the ICU and see them," an understandably exhausted mother said. "It's hard to believe that it really happened. It's like I am still in a dream and wondering when I am going to wake up. But it's a happy and exciting dream.

"I'll just be glad to get them all home and put some weight on them. They are all so tiny right now, it scares you to touch them."

Diana may be released from the hospital early next week. "They haven't given me an exact date when they are going to set me free," she joked. Her babies likely will be hospitalized for another several weeks, depending on their progress.

Meanwhile, a whole crew of relatives are setting up the nursery in the couple's Holladay apartment. Many items, including cribs and newborn baby clothing, have been donated by generous friends and relatives.

But the parents aren't naive about the tremendous expenses facing them.

Initially, their primary concern was insurance coverage. In March, the couple received notification that FHP would no longer renew its contract with Dairy Queen of Utah, where Diana and Ken were employed.

However, FHP offered, and Diana accepted, a conversion plan that pays 80 percent of their medical expenses.

Still, Ken Ching-Jing Hsu, who immigrated from Taiwan five years ago, knows that providing for his four premature infants and their three older sisters isn't going to be cheap. Although his bachelor's degree is in fine arts, he has been managing two Dairy Queen drive-ins while launching a career as a professional artist.