When Theresa Welsh, a Haddonfield pediatrician, agreed to donate her kidney to a stranger, to start a chain of kidney donations, she had one requirement: get the operation done with before her first grandchild arrived.

The surgery was Oct. 22. She was back to work part time in two weeks, seeing her own patients. And she will spend Christmas Day with her new grandson, Evan, born Dec. 5.

"I do feel perfectly fine," she said. Her right kidney has stepped up its performance beautifully, making up for the loss of her left.

"The pace of my life is back to full speed," she said. "In the quiet moments at the end of the day, I am content. The minor pain and imposition of being out of commission for three weeks was so minimal compared to the enormous benefit.

"The outpouring of love from the community has been amazing," added Welsh, whose story was chronicled Nov. 17 and 18. "I have received support from old friends and also from complete strangers. Many have shared the stories of battles their loved ones fought, and in some cases lost, with kidney disease."

She said the experience has made her a more empathetic doctor, especially when making hospital visits.

"I think I've always tried to be compassionate," she said. "But when you're one of those patients, sitting in that hospital bed, it's a whole different experience.

Welsh's act triggered a chain of donations that led to five transplants.

Her kidney went to a man in New Hampshire, who is recovering well but declined to participate in this article. Welsh has no idea who he is. The New Hampshire man had a friend or spouse willing to donate to him, but the two were not compatible. His body would have rejected his partner's kidney.

So when the New Hampshire man got Welsh's kidney, starting the chain, his partner donated a kidney to a man in Ohio.

The Ohio recipient also had a partner willing to donate, but incompatible, so the Ohio partner donated to Felix Reyes, 55, in New York, the third recipient in the chain.

"I'm feeling pretty good," Reyes, a school security guard, said last week. "My health is improving. My blood pressure is down for the first time in years."

Reyes' wife, Delma Hastick Reyes, donated a kidney to Tom Darby, 60, who lives in Long Branch, N.J., and who had been on dialysis for four years.

Like everyone in this chain, Darby didn't know the identity of his donor. He knew it was a woman.

"I call my kidney Sarah Leigh," he said. "Everything is great. She's functioning well. She's peeing like a racehorse.

"I can eat now," he added. "No restrictions. I can have an orange now. I can have a banana. I can have tomatoes. All those foods with phosphorus and potassium [that sick kidneys have trouble removing]. I eat yogurt like crazy. I run after my 3-year-old granddaughter now, whom I watch three days a week."

Darby's brother, David, 53, donated to Scott DeVinney, 63, a retired firefighter from Margate, N.J. DeVinney received his kidney back at Thomas Jefferson University Hospital in Philadelphia, ending the chain where it began with Theresa Welsh.

Neither the Reyeses nor Darbys had any concept of how the chain worked, that it was started by what is known as an altruistic donor. They thought the chain was simply a group of pairs, swapping with one another.

"Wow," said David Darby, in a hushed reverence. "This lady just wanted to donate? Let me get this right. She just went in and did this, and started the whole thing off? That just blows me away. That's the truest sense of giving, that you don't get anything in return. That's beautiful. Tell that person she's an awesome person."

His brother Tom added: "I am totally in awe of her. She is a hero."

Reyes said, "Anyone who gives a kidney to a stranger, she has to be blessed."

DeVinney, the retired firefighter, said his kidney is doing extremely well - so well he finally was able to get his hip replaced. He and his wife, Jean, will spend Christmas at home, but plan to go to Florida in February, for the first time in years.

"I can't thank her enough," Jean DeVinney said of Welsh. "We just want to thank all the donors for giving us a happier and healthier New Year."