Sara Connell was unable to have her own child because of fertility problems, and she didn't want to adopt. The situation seemed hopeless, until an unlikely surrogate stepped in: her mother. By carrying her daughter's child, 61-year-old Kristine Casey technically gave birth to her own grandson. While the idea may seem outlandish, it's not as unsafe — or as uncommon — as you might think. Here's an instant guide to what happened:

How did this happen?
Connell decided to have a baby in 2004, at the age of 35, but she was no longer ovulating. After infertility treatment, she became pregnant, but gave birth to stillborn twins; a subsequent pregnancy ended in a miscarriage. Meanwhile, her mother had retired and was looking for a "deeper calling" in life. After doctors assured everyone involved that Casey could safely give birth, the Connells gave a green light to the idea.

How did the process work?
Casey took hormones to make her uterus act "young," and she got pregnant on her second round of in vitro fertilization. The pregnancy went normally, and the C-section procedure went smoothly. "The surgery itself was uncomplicated, and the emotional context of this delivery was so profound," said one doctor. Casey did experience some kidney complications after the birth, but recovered quickly. "From the very beginning," she says, "the moment I've wanted is the moment the baby is in their arms."

Is this a first?
No. A 55-year-old Virginia woman carried her daughter's triplets to term in 2004, and in 2007, a Florida woman acted as a surrogate mother for her daughter, who had undergone a hysterectomy. "The exact number of grandmothers birthing grandchildren is unknown," according to the Chicago Tribune, "but infertile couples are turning to relatives more and more," both for financial reasons and because legal problems are less likely to arise with an intrafamily arrangement.

Sources: Chicago Tribune, San Francisco Chronicle