Now her doctor says she should have bought lottery tickets: The Cherry Grove woman and her daughter, Addison Paige, are both doing just fine nearly six months after delivery.
Loudon, now 30, had already survived one potentially deadly bout with blood clots, and doctors warned her against pregnancy, worried she might not survive a second round.
Her pregnancy was a surprise. But Loudon credits a combination of determination, medicine and prayer for her survival - and her daughter's healthy birth.
"It was very, very scary," she said. "You have all these doctors sitting there, and they never once said, 'It's going to be OK.'"
To think, it all started with a back ache.
It was July 2006, and Loudon went to the hospital, hoping to find out what was causing the severe pain.
"They couldn't find anything and they sent me home," she said. "Then a couple days later, the pain moved around to the front of my stomach area."
A second trip to the emergency room produced no answers.
Two days after that, her legs swelled up, and the pain was so bad she couldn't walk.
That time, she got an answer: Blood clots. She was admitted for 17 days and treated with blood thinners.
When she was released, doctors referred her to a specialist at University Hospital.
There, doctors did an ultrasound, and she was immediately admitted to the hospital.
"They found out I had blood clots in both legs, from the rib cage down," Loudon said. "There were so many they couldn't even count them all."
What the five doctors did count was especially scary: Three blood clots were lodged in a major blood vessel in Loudon's heart, and two more in the major artery in the abdomen and pelvis.
The blood clots in Loudon's heart were lodged in the vena cava, the blood vessel that carries blood from the body back to the lungs to be re-oxygenated.
She needed immediate surgery. Amy Reed, a vascular surgeon at University Hospital and the University of Cincinnati, cleaned out the blood clots and placed five permanent stents to widen the affected arteries and prevent future clots.
"The real concern was that one of those blood clots could have dislodged and gone to her lungs and killed her," Reed said.
After the surgery, she was prescribed blood thinners to prevent future blood clots, and over the next several months, was slowly weaned off of them.
Loudon and her doctors don't know why she developed the blood clots. She is a non-smoker with no family history of clotting disorders.
In July 2008, she and her husband, Cory, decided they wanted to have a baby.
They talked to Arthur Evans, chairman of the obstetrics and gynecology department at the University of Cincinnati and a specialist at University Hospital.
Evans warned the couple that pregnancy could increase her risk of developing more blood clots, and the weight of the developing baby could crush the stents in her abdomen and pelvis.
He suggested they see a fertility specialist about finding a surrogate to carry their baby.
Then, sometime around Veteran's Day 2008, Loudon learned she was already four weeks' pregnant.
Family, friends and doctors warned the couple of the dangers she might face.
"They told me there was a 50 percent chance I might die," Loudon said.
The Loudons decided to focus on the chance she'd survive, and chose to continue the pregnancy.
So Evans and Reed started working on a plan to help Loudon and her baby survive.
Few women have gotten pregnant after having abdominal stents implanted, Evans said, and only half of them have survived.
Loudon went back on blood thinners. As her pregnancy continued, she underwent 10 ultrasounds so doctors could see how her growing baby might be affecting the stents in her abdomen and pelvis.
Surgery to go in and repair or replace the stents was a possibility, Evans said, "but it would have been a very difficult situation."
At seven months, she switched from working full-time to three days a week.
"On Tuesdays and Thursdays, I sat with my feet up," Loudon said.
Everything could have gone wrong. But nothing did.
"She's a very brave woman,'' Evans sad. "She was very determined to carry this through. It's always amazing to me how brave women are who have very difficult medical problems during their pregnancies."
On July 6, just two weeks before she was due, Addison was delivered by Caesarean section.
A vaginal delivery was too risky, Evans said. Labor would have put too much pressure on the stents.
He was thrilled to see his patients beat the odds.
"She probably should have been buying lottery tickets," he said. "Maybe one for her and one for me."
Since Addison's birth, Loudon hasn't developed any more blood clots, and she's now off all medications.
"It went perfectly," Loudon said. "It was scary, but it was well worth it. We have our little miracle baby."