Marie Paulson was advertising a 2 1/2-month-old horse for sale through the classified ads when she got a call about the other ad she'd placed - the one seeking a baby to adopt.

"Utah LDS family wants to adopt your infant/toddler. Mini farm, horses, brothers and sisters. Let's get to know each other. Call Marie and Mike. . . .""I'm calling about your ad in the newspaper," said the voice on the other end of the phone.

Marie's first thought was that she finally had an interested buyer for her horse. But when she heard the high-pitched cry of an infant in the background, it registered that this call wasn't about a horse.

Moments into the conversation, it was clear the birth mother wasn't interested in spending time getting acquainted. She just wanted to give away the 3-month-old baby that she said she was no longer able to care for.

At that point Marie started to worry. "I thought, `I better get this baby before the baby gets hurt.' "

Later that evening, at the first arranged meeting, the birth mother flounced by Marie and her husband, Mike, and locked herself in the bedroom. Marie remembers that she seemed to be high on drugs - or something. The mother's boyfriend urged the couple to take care of the baby, who had just been bathed and appeared healthy.

Teddy-bears dance across the ruffled curtains in the upstairs bedroom in the Paulsons' suburban home. The nursery that sat empty for seven months is quiet again, now that the want-ad baby the family loved for five days is gone.

Marie, who to protect the safety of her family asked that their real names not be used, has dark hair with curls that flip back to frame her face. The glasses that perch on her nose slip downward at regular intervals. She is warm, talkative and disarmingly open. When one child spills juice in the kitchen, she calmly supervises as her oldest helps out on the mop patrol, all the while talking about her baby hunger and the upstairs nursery that is still empty.

Marie's hysterectomy several years ago - she suffered endometriosis before it was commonly diagnosed - robbed her of the dream of bearing a large family. She and her husband, like a growing number of Baby Boomers, feel the pain of an empty crib.

The Paulsons personify a startling statistic: In 1989, one of every six couples will suffer the heartbreak of infertility.

Legalized abortions have helped make the baby pool scarce. The wait for healthy babies at Utah's adoption agencies starts at two years.

Many potential parents have turned to independent adoptions to create the family they've always wanted. And with infants in short supply, some Utah families - especially those who might not qualify through adoption agencies because they already have several children or are over the age of 40 - have become more aggressive in the baby hunt.

Wants ads and doctor solicitations are two of the main networking methods that baby lawyers, like David Radis in Los Angeles, recommend. He calls it networking, and despite the competition for babies, he says such methods work.

"Nowadays both birth moms and adoptive couples are being much more aggressive about finding each other, because of the frustration of so few babies," said Karen Larsen, an adoption worker at Catholic Community Services in Salt Lake City.

Through adoption, Marie and Mike have built a family that fits together like Chinese boxes. The first children they adopted had been physically abused. Unwittingly they'd fallen victim to a bureaucratic Catch-22. Although they qualified for adoption after a thorough screening, they were told they were ineligible to adopt a healthy child because they already had children.

Frustrated, like thousands of infertile couples across the nation, they turned to more creative and aggressive means to find the baby they yearn for.

Their want ad was just one of the dozen placed in Salt Lake newspapers every weekend.

"Some people just have the idea that we are crass baby-exchangers," Marie said. "We're not. We're infertile couples who want to have big families and are willing to work to get our babies."

Marie said others are unaware of the pain she and her husband suffer in their quest to adopt a child. "Some people are so naive. They think a baby magically appears one day on your doorstep. When they find out my children are adopted, they say, `Oh, you get them the easy way.' It's not. I've suffered labor pains for 4 1/2 years in my mind."

But local adoption professionals are concerned about the growing trend of independent adoptions.

"Yes, I could understand a couple who desperately needed a child who would go through any means," said Colleen Burnham of Children's Aid Society of Utah. "But they don't know what they're getting. There are dangers. They may not know enough about the child's background to know if that child really fits into their family."

Sandy Dreis of Children's Service Society of Utah said agencies view the child as their client, and the birth mother and the adoptive parents are resources. And agencies work to place a child in families that would be a good match, something that independent placement can't always guarantee.

Dreis and Burnham agree that adoptions arranged independently don't always consider the needs of the birth mother after the adoption papers have been signed. Some birth mothers regret giving up their child. Agency counselors are trained to hold their hands through such crises - often avoiding the heartache of annulling the adoption.

"Doctors do good medical work, and lawyers do good legal work. But people really need good social work," Burnham said.

"One of my greatest concerns is the young woman who releases a child, who is left with no one to help her through the grief process. The attorney takes the child and no one thinks about her again. The woman will be going through such a grieving process that she thinks she's made a mistake and she sues to get the child back."

Dreis said the baby hunger is so strong in Utah that it feeds an active underground market of infant sales. "We hear a lot about a gray market where the girls are being paid with cars and things. The law says that any gift is fine, as long as it doesn't influence the mother. We have a lot of gift-giving going on in this state.

"We literally get young women calling, and they shop to find where they can get the best deal. I had a woman call the other day, and she wanted to sell a sibling group."

Burnham said baby-selling is definitely illegal, without consideration of its moral implications. "But having said that, it happens."

But Marie and Mike Paulson, and other Utah couples, remain staunch advocates for independent adoption - and the creative methods they employ in their baby search. Like the adoption professionals, they strongly censor those who illegally buy babies. Using their own children as examples, they point out the benefits of independent adoption. They stay in touch with their birth moms, sending pictures and notes frequently. They tell their children bedtime stories about how they came to be Paulsons.

Despite the pain they suffered as a result of their want ad, the couple plan to continue pursuing another baby through the independent route.

That first hysterical meeting with the birth mother was the start of a turbulent five days for the Salt Lake Valley couple, which included court appearances for adoption, appointments scheduled by the birth mother that she later missed. Marie spent at least one sleepless night under the threat of arrest for kidnapping.

Marie and Mike offered to enroll the mother in a drug treatment program. In subsequent telephone calls, the birth mother waffled about giving up the child. She finally arranged several court dates to sign the adoption papers, but then neglected to appear.

At one point, the mother charged Marie was blackmailing her to take the baby, despite having placed the initial phone call herself. But the baby's relatives - including the baby's father and aunt - begged Marie to adopt the child.

Another day the mother's boyfriend called and asked: "What's the story? Are you going to buy this baby?" Marie was chilled by the question.

Once, the baby's father telephoned to ask Marie and Mike to sign a collateral agreement to bail him out of jail. They did.

Three weeks after the initial telephone call from the birth mother, the Paulsons received a phone call asking if they still wanted to adopt the baby, then asking them to bail another relative out of jail.

"The only contact I had with the mom is when I called her," Marie said.

The Paulsons learned five of the mother's six children had been adopted or were under state custody. After the last court date, when the mother again failed to appear, Marie and Mike Paulson turned the infant over to the state Division of Family Services. State social service employees had already received two calls charging the mother with child neglect but had been unable to locate her.

Because they are interested in adoption, social workers determined Marie and Mike wouldn't be suitable foster parents for the 3-month-old boy. In Utah, the foster-care program is designed to be a temporary home while families work to regain custody of their children.

Having suffered through the emotional trauma of having a child torn from her embrace, Marie is grateful that the child she loved as her own is now in a secure home. She has a hard time answering when her youngest child asks what happened to his baby brother. But she remains philosophical.

She is confident there are children in the world who need a good home, the home she and her husband would provide.

"My feeling is my children are out there. They really are my babies."

*****

(CHART)

Adoption help

A local network of adoptive parents and professionals is available to help others walk through the legal and emotional hurdles of adoption. Here are some first-stop resources for couples seeking more information about family additions through adoption:

AGENCIES:

- Catholic Community Services: 328-9100.

- Children's Aid Society of Utah: 533-5558; or 393-8671.

- Children's Services Society: 355-7444.

- LDS Social Services: 566-2556.

- Utah Adoption Service for Women: 466-9975.

- Children's House International: 272-4822.

- Western Association of Concerned Adoptive Parents - 272-8459 (Specializing in foreign adoption.)

- Utah Division of Family Services: 468-5400. (For adoption of children with special needs.)

SUPPORT GROUPS

- Resolve: 350-8807. The local chapter offers a 24-hour answering service. The group is a national, non-profit organization offering counseling, referral, support and education to infertile people.

- Families Involved in Adoption: 298-5021; Local informational support group for adoptive families as well as those interested in adoption. Offers referrals to local agencies, in addition to meetings and classes.

- Rocky Mountain Adoption Exchange: 359-7700. An informational and support group for adoption of special needs children that coordinates the hotline for KUTV's "Wednesday's Child" program.