GARY AND KATHY, both geologists in Houston, are the grateful parents of twins--a boy and a girl. The babies have big eyes and tufts of hair that stick straight up, making them look like alert, crested birds. Gary smiles every time he looks at them. "Kathy basically crawled through broken glass to get these kids," he says.

Gary also went through a painful ordeal to produce these babies. A few years ago, he had surgery on his testicles to improve his sperm count. It didn't work. So the couple tried IVF. Kathy took drugs to stimulate her ovaries, then had eggs removed. Doctors cut into Gary's testicles to extract sperm, fertilized the eggs in a laboratory dish, then put the resulting embryos into Kathy's uterus. But she didn't get pregnant.

"I was having trouble with seeing pregnant women, seeing children, going to baby showers," Kathy says. "The thought of that was just, no way. Some days you're fine. But other days you're a wreck."

"I was more worried about Kathy than I was about having a child," Gary says. "This is pretty stressful, particularly when you're loaded up on all the drugs they pump into you. It was getting pretty stressful for both of us, so, being a guy, I wanted to find a solution. By God, let's just go out and adopt a baby."

Kathy and Gary looked into adoption, but found it could be as expensive IVF (a single IVF cycle costs $7-15,000). And they feared the birth parents might someday demand the baby back, even though that almost never happens. The couple worried about the prenatal care an adoptive baby might receive. What if the birth mother drank or smoked? Besides, Kathy wanted to experience pregnancy.

"Well meaning people who just don't understand," Kathy says. "They see what you're going through and they say, 'Why don't you just adopt?' And my answer is, 'For the same reason you didn't.' Because they are invariably people who have their own biological children. 'Why didn't you adopt?'"

Gary adds, "It's something that's inherent in everybody, in all species. You gotta go out and procreate."

When the couple learned of a less painful technique for extracting sperm from a man's testicles, they decided to try IVF again. This time the technology worked. In March 1997, Kathy gave birth. The first picture in their baby book is a black and white shot of what looks like lumpy soap bubbles. It's the twins as embryos, photographed through a laboratory microscope.

Today, they're energetic babies. The boy kicks and babbles as Kathy changes his diaper, shrieking with laughter when she coaches him to "gimme five!" The girl waits her turn, cuddled in Gary's arms.

"They're perfect," Gary says. "Not that we have a particularly objective opinion." Gary doesn't want more children, but there's no question in his mind that the twins were worth all the trouble, pain and expense. "Knowing what we know, would we do it again?" he asks. Both of them answer, "Yeah."