Carolyn Savage told "Dateline NBC" that she has no regrets about carrying the baby boy and giving him to his biological parents, Shannon and Paul Morrell, who live in the Detroit suburb of Utica, Mich., after giving birth in September 2009. Savage didn't want to have an abortion and had no desire to raise the child.
Savage, who's in her 40s, and her husband, Sean, live in the Toledo suburb of Sylvania with their three children. The couple told "Dateline" said they were still hoping to have a fourth of their own and even hired a surrogate as Savage was pregnant with the Morells' child, Logan.
Carolyn Savage said they were elated to learn in late August that the surrogate was pregnant. But a week after Savage gave birth, she said the surrogate called to tell her that she had miscarried.
Although she was devastated by the news at the time, Savage also said "there is no way to fill that void." Savage won't have another chance to carry her own baby because of her age and difficulties during her earlier pregnancies.
"We're to a point now that if we don't have any more children, I think we're good," she said.
Embryo mix-ups at fertility clinics are extremely rare, and this is one of the only known cases that ended amicably.
The Savages said they have since learned that two factors contributed to the mix-up at the fertility clinic, which neither couple has identified.
One was that Shannon Morrell's maiden name was Savage, and she hadn't it changed until after using in vitro fertilization to become pregnant with twins. After their daughters were born in 2006, the Morells had six frozen embryos left and planned to try for another baby.
The other, Savage said, was that a clinic employee had discovered a mistake on her birth date in the clinic's files. Her birth year was incorrectly listed as 1967, instead of 1969, she said.
The couples have stayed in touch, and Shannon Morell told "Dateline" they would continue to do so as Logan grows up by getting together "probably a couple times a year." And when he's old enough, Morell said she would like her son to thank Savage for carrying him.
"It's important he realizes that she protected him for nine months," Morell said.
The Morells co-wrote a book with author Angela Hunt about their experience, "Misconception," which was published in April. The Savages have their own book, "Inconceivable," due out Monday.