Little Macie McCartney was welcomed into the world not once — but twice.

Four months into Keri McCartney's pregnancy, doctors reportedly noticed a tumor growing on the baby's tailbone.

Doctors discovered that the tumor was stealing blood from the fetus and weakening her heart. So, at 25 weeks, surgeons at Texas Children's Fetal Center cut into McCartney's abdomen in an effort to remove the life-threatening mass, according to a CBS News report.

“Prenatal surgery is still done in very few select areas in the United States,” Dr. Manny Alvarez, FOXNews.com's managing health editor, said Monday. “And there are a limited number of medical conditions where prenatal surgery is indicated and this is one of them.”

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Once the abdomen was open, doctors pulled out the entire uterus — and then half of the baby.

At that point, surgeons carefully cut away the non-cancerous tumor, which reportedly was the size of a grapefruit.

“This operation is similar to a Caesarean section,” said Alvarez, who is chairman of the Department of Obstetrics, Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey.

“Half of the baby is extracted — only the part that needs to be operated on. And then she is put back into the womb," he said. "The womb is then closed and carefully monitored for signs of premature labor and other complications.”

And fortunately there were no other complications. The baby grew for another 10 weeks inside her mother.

"We definitely had hope, but at the same time there are those times things don't go your way and God has other plans," McCartney told CBS News.

After spending a month in the hospital, Macie "Hope" McCartney was expected to go home with her parents on Saturday.

This type of tumor is a rare and a sometimes fatal condition affecting one in 35,000 babies.

Other conditions such as diaphragmatic hernia, renal obstruction and vascular abnormalities of the placenta also require prenatal surgery, Alvarez said.

On a related note, Australian surgeons were credited Monday for saving the leg of an unborn baby by operating on her while her mother was just 22 weeks pregnant.

Marrecca Fiore and Karlie Pouliot contributed to this report.