"They took her out of the room, and they wouldn't let us see her," said Garrison, 15, of Wellington, Fla.
Finally, after six hours of tests, Garrison got to look briefly at her baby and see what doctors were so concerned about.
"She looked like a normal baby, but I could just tell something was wrong," Garrison said.
Brielle was born without any eye tissue at all, a condition called anophthalmia that leaves a person irrevocably blind.
Garrison also learned this rare diagnosis was one that is almost always missed by ultrasound -- even though hundreds of genetic diseases and deformities once discovered at birth can now be detected with the latest ultrasound technology.
How Ultrasound Could Miss Brielle's Condition
"If you look at the ultrasounds, where the eye sockets are they're just black because the eyes are made of water," Garrison said. But Brielle's eye sockets were just empty.
Dr. Aaron Fay, director of Ophthalmic Plastic Surgery at the Massachusetts Eye and Ear Infirmary, is currently treating 10 patients with the rare disorder.
The condition of either partially (microphthalmia) or completely missing eye tissue occurs in 30 in 100,000 births, and although in concept, Fay said, doctors could perhaps see the missing eyes in utero with an MRI, it is rarely diagnosed in the womb.
"There are skeletal stigmata that could be picked up," Fay said. "But it's most frequently diagnosed at birth."
The condition is not inherited, Fay said, so families have no clue that their child may be carrying the deformity. It could be a genetic mutation, or an unexplained occurrence in the first few weeks of pregnancy.
Garrison said Brielle's genetic screening came up clear.
"She got a chromosome test, and she came back as a normal baby girl," Garrison said.
However, eye and genetic screening specialists say a genetic mutation can sometimes lead to anophthalmia.
How Doctors Could Possibly Know about Anophthalmia
If a doctor somehow suspects a problem with the eyes, which happened to baby Faith featured by ABCNews.com in November, then Watson said mothers could go in for prenatal genetic screening.
"We certainly can test for, with great accuracy, for chromosome abnormalities and that has been the case for 40 years," said Dr. Mark Evans, a member of the American Congress of Obstetricians and Gynecologists.
"There are hundreds of them, however the vast majority occur with chromosome 21, 13 and 18," said Evans, of Comprehensive Genetics in New York City.
With such old technology and more genes discovered every day, one might wonder why every woman wouldn't get prenatal genetic screening.
"But we do not routinely test everybody for everything because we'd bankrupt the country," Evans said.
Evans also thought that occasionally a false security in ultrasounds keeps prenatal genetic screening rates low, in addition to the high costs.
"What has happened in the last 20 years is that many women are being falsely reassured by ultrasound and not going on to genetic testing," Evans said. "In some places the birth rates of these (genetic) problems have gone up."
As ultrasounds for women seeking prenatal care have become almost universal in the United States and, as Evans argued, perhaps overly reassuring, doctors also say that the prenatal imaging has evolved into high tech and low tech uses.
Now, a portion of obstetricians have become experts in using prenatal imaging to diagnose genetic disorders an ultrasound wouldn't have caught a generation ago.
"What you can see in prenatal imaging is changing enormously," Watson said. "You end up with two different kinds of people who do imaging. One level is the standard obstetrician on the corner, who can do the basic measurements and tell you if your baby is growing normally and you end up with a picture on your fridge."
Not Every Obstetrician is An Expert in Prenatal Imaging
The other, Watson said, are people who specialize in high-risk pregnancies and can use ultrasounds to diagnose, or even treat more and more genetic abnormalities.
"At the first level it's a matter of someone being suspicious that something is going on," Watson said. "The patient can then go to an obstetrician who specializes in high risk pregnancies."
Doctors can even treat a few of the birth defects in the womb -- such as Spina bifida or twin to twin transfusion syndrome -- if ultrasounds pick up on the disorder, Watson said.
Using Ultrasound to Find Red Flags for Genetic Disorders
"There are certain markers on ultrasound that change the odds (of a genetic disorder), for example the nuchal translucency, which is thickness of the back of the neck in the first trimester, can be a marker for Down syndrome," said Evans.
Garrison said she chose to go to the public with her story because, her family had never heard about Brielle's disorder, unlike Down syndrome or other more well known conditions.
"It's just so rare, most people don't know that it really exists," said Garrison "If more people know about it, then it's more likely people will study it."
For the next few years, Brielle will have to see doctors for conformers -- balls filled with hydrogels to increase the size of her eye sockets -- in order for her facial structure to grow normally.
Fay says he and his colleagues at Massachusetts Eye and Ear are continually looking for new ways to help children with the condition grow as normally as possible before they receive prosthetic eyes.
Since speaking with ABC News affiliate WPBF in West Palm Beach, Fla., Garrison said parents of children with anophthalmia or microphthalmia have contacted her seeking support.
"A lot of worse things could have happened and thank god they didn't," Garrison said. "I see her just as any other baby. She does everything any other baby would." ( abc news )