Because of this, Daigle will never qualify to be a surrogate again, and doctors are unsure if she will be healthy enough to sustain a pregnancy with her husband, whom she married after the twins were born in 2008.
Surrogacy experts say women need to be educated about entering into surrogacy before completing their families. Multiple pregnancies, especially twins, which are more common in IVF, can be risky.
"What if they remarry and want a child?" asked Synesiou. "Every pregnancy reduces the chance of that."
Her agency turns away what are now being called "serial" surrogate mothers, some who have gotten pregnant seven or eight times. "I have to lose them," she said. "I can't live with the guilt."
"They want to do it over and over again and they can't stop until their bodies make them stop," said Synesiou. "There's something psychological going on."
"The first time they want to help and I get it," she said. "The second time, it's a great experience, and I get it. The third or fourth I wonder what went wrong that they didn't feel fulfilled. I worry about these girls."
But Daigle says she doesn't regret her decision, even though some wrongly accuse her of doing it for the money. "I've also had plenty of people say to me, 'I don't understand why you did it, but thank goodness there are people like you out there.'"
Soon, her doctor will do another electrocardiogram and see if Daigle can have a child with her husband. "There a good chance, and I would like to," she said.
As for her surrogate children, Daigle occasionally speaks to Zoe, who now lives with her twin brothers in The Netherlands. She sends birthday cards to all four of the children and has warm relationships with their fathers and even the Raftopol's egg donor, keeping in touch on Facebook.
"I was never treated like object," she said. "I am like a member of the family. If I do this, I have a permanent lifelong commitment."
"I love all these people -- all the parents, the kids," said Daigle. "I consider myself lucky to have been chosen. There's a lot of trust that goes in to this. They trust that I am careful with my body and I am caring for their most precious thing. I appreciate their trust."