She had supported her daughter through years of trying, helping her through the anguish of failed pregnancies and rounds and rounds of in vitro fertilization.

When nothing worked, 61-year-old Kristine Casey offered the very last thing she could: her healthy, post-menopausal uterus.

Last week, the Virginia woman gave birth to Finnean Lee Connell via cesarean section at a hospital in Chicago, where her daughter Sara Connell lives.

When a B.C. couple discovered that the fetus their surrogate mother was carrying was likely to be born with Down syndrome, they wanted an abortion. The surrogate, however, was determined to take the pregnancy to term, sparking a disagreement that has raised thorny questions about the increasingly common arrangements.

Under the agreement the trio signed, the surrogate’s choice would mean absolving the couple of any responsibility for raising the child, the treating doctor told a recent fertility-medicine conference.

Sally Rhoads is passionate about surrogacy. The 32-year-old mother of three (ages 12, seven and 10 months) lives near Stratford, Ontario. She has been a successful surrogate once and an unsuccessful one nine times. Although her commitment to surrogacy almost killed her, she remains an advocate for a practice that is highly restricted in Canada and banned in some U.S. states.

This: When did you first become interested in surrogacy?

Rhoads: After my first child in 1999. I had really enjoyed being pregnant…

Mac and Ella Comber were delivered by C-section on Sept. 23, 2006, weighing 5 lb. 10 oz. and 5 lb. 11 oz. respectively. Both were strong and healthy, though Mac spent a short time in an incubator to help clear some fluid from his lungs. Ella, with her olive skin and dark hair, had her mother’s complexion, while Mac, with his fairer skin, looked more like his father.

A week after their birth, Mac and Ella’s mother nursed them for the last time in the hospital, bid their father and the twins farewell, and returned home to her husband and two daughters aged 7 and 5.

The heartbreak of infertility is driving thousands of Canadian women to the costly science of assisted reproduction. This is the story of the boom in a rapidly advancing medical field, the agony of hope it offers, and the strangers willing to give the ultimate gift: a baby.

Last summer, Donders began a month-long series of blood tests and then vaginal ultrasound before the frostie was placed in her uterus. The embryo didn’t implant, however, and Donders was just coming to terms with the end of that particular dream when she realized in September that she was pregnant again without any medical assistance. Although everything seemed fine….

For many Canadians, surrogacy is a controversial issue. Should a woman be expected to relinquish the child to which she has just given birth? Is it fair to the infant to be taken from the only mother he or she knows? Should women be paid to carry another women’s child?

Some call it “baby selling.” Others see it as the rich renting the wombs of the poor. But Sally and her husband of Stratford call it a gift.

“It’s nine months of my life to give two people a family,” said Ms.Rhoads.