A tiny blue-eyed girl made her entrance into the world. An obstetrician opened his hands to receive her, just in time. A nurse started to carry the baby to her mother, but another nurse stopped her.

Someone whisked the child from the delivery room. The mother protested, but her baby was gone. The child was taken to the nurses' station, apart from the other babies in the nursery and mostly out of sight. The mother demanded her newborn. The nurses stalled. The mother shouted: "You better bring my baby right now!"

Finally, more than 12 hours later, and only after the mother had telephoned a hospital administrator, did they bring her daughter.

All these things Patti Pool, 22, would hold forever in her heart. And these: how the little girl's face peeked out from a white blanket, and how she had puffy chipmunk cheeks and pointy lips just like her own. Patti sat up and propped her daughter between her knees. She cradled her tiny head in her hands. Awed, she saw that her daughter was beautiful. She concentrated on what she wanted to tell her — and quickly, because the nurses might come back and take her away. She leaned forward slightly and stared into her baby's eyes.

"I'm your mommy," Patti began. She started sobbing. "But you are not coming home with me." She had already told her baby why, when the baby was growing inside her. She had told her that her name was Kendall, because she had dreamed since she was a teenager of giving her firstborn daughter that name. "I am giving you up for adoption. I want you to have a good life. I am not giving you up because I don't love you. I am doing it for you."

It was Oct. 21, 1983. The nurses took Kendall from her mother's arms.

No father went to Antelope Valley Hospital in Lancaster, just north of Los Angeles, to see Kendall. Only a grandmother came, but she was turned away. Kendall, unofficially, belonged to someone else — a couple Patti had met just twice. Patti was a bartender with a 2-year-old son. She wasn't living with Kendall's father. She had tried to give Kendall to another couple — but the woman got pregnant. Now this, it seemed, was Kendall's only chance for a home.

The next morning, Patti was discharged. She forced herself to put one foot in front of the other, to walk out the hospital door.

Kendall, only 2 days old, was left behind.

A good or bad thing?

NEARLY TWO-THIRDS of Americans have encountered adoptions in their families or with friends, according to a recent survey. Kendall Pool, however, was special; she was a pioneer in an edgy experiment that has grown into the phenomenon known as open adoption.

Her birth mother would reenter her life and play a large part in it. Children in fully open adoptions remain close to their birth families. They get frequent visits, usually from their birth mothers. Those visits can be quarterly, monthly — even daily. Some birth mothers and adoptive mothers cheer on their children together at soccer games.

Adoption agencies estimate that 90% of infant adoptions in the United States are open enough for adoptive and birth parents to meet at least once — and a quarter are completely open. In 13 states, including California, recent laws allow courts to enforce open-adoption contracts stipulating types of visits and their frequency.

Forty years ago, closed adoptions were the rule. They saved embarrassment, even shame, sometimes for an unwed mother, other times for an infertile couple. Even in the early 1970s, some unwed mothers were sent away to give birth. Some pregnant women gave birth blindfolded and with their hands tied, or were drugged into comas so they would neither see nor touch their babies. A "clean break," it was called. Their children had their original birth certificates sealed. Many were never told they were adopted.

Often, however, something was amiss: These adopted children were different from everyone else in their families. Sometimes they found out the truth: They unearthed their adoption papers. Or Uncle Charlie, drunk, blurted out that they weren't really kin. The children had been living a lie: How could they trust their adoptive parents again? Who were their real parents? Were their birth mothers Hollywood starlets? Sunset Boulevard prostitutes? Fantasy mothers who were perfect and would someday come and get them — or, worse, would not?

Even children who had been told they were adopted knew very little about their birth families.

Why had they been given up in the first place?

Social workers noticed worrisome signs. Adoptees struggled with their identities more than most teenagers. Many had trouble with trust and commitment to good relationships. Among children who had been adopted as infants, had never been in foster care and had grown to school age, 41% had seen a counselor for emotional or behavioral problems, compared with 18% of their non-adopted peers, according to a 2004 study by Illinois State University. And 24% had enrolled in special education classes, compared with 9% of non-adoptees.

Some social workers, notably in California, Wisconsin, Michigan and Texas, said adoption had to open up. Some birth mothers joined their cause.