When Miss Guyana Niketa Barker, 24, was a teenager she and her family had to figure out how to start all over after escaping a home fire.
"I grew up in a small town," Niketa told ET's Nischelle Turner. "I lost my home in a fire when I was 15 years old. We lost everything. We were unable to save anything. Everyone ran out of the house with no shoes on their feet."
Two years after the fire, Niketa lost her father in "an extremely traumatic event," according to the Miss Universe website, but today she is two years away from obtaining a degree in Medicine & Surgery from the University of Guyana.
"It's part of our curriculum to deliver 12 babies," she said. "The most amazing part for me is when the baby is first born and before he or she takes that first breath. That moment of silence -- that's the most amazing part for me."
Miss USA Nia Sanchez, 24, used her obstacles to fuel her ambition.
"When I was younger my parents separated and I lived in a women's shelter with my mom," Nia said. "No matter where you come from or what's happened in your life, it's always motivated me to feel like I can make anything happen."
Like many other girls, 24-year-old Miss Puerto Rico Gabriela Berrios had to overcome body-image issues caused by bullies who destroyed her self-esteem.
"I once weighed 170 pounds," Gabriela said. "Yes, every kid in my room told me anything to make me feel bad. My self-esteem was very low, and after I lost the 60 pounds, I still felt fat so I kept going and kept going until I got to 110 pounds."
According to Gabriela it was her family that helped get her back on the right track.
"My family told me, 'You look great. You don't need to lose more weight. You look amazing. Look at the pictures and everything you have done,' and I did that," she said.
Miss British Virgin Islands Jaynene Jno Lewis, 25, spent five years in the Navy where she had to overcome sexist stereotypes.
"It was more or less [a man] telling me that women belong behind a stove and not in the military," Jaynene said. "I pulled up my socks, combed my hair back and showed him what a woman stands for and what women mean in the military and I showed him I could do the work just as much as he can."
The 63rd Miss Universe Pageant (judged by William Levy, Manny Pacquiao, Kristin Cavallari, Lisa Vanderpump and Louise Roe) airs Sunday, Jan. 25 at 8 p.m. ET on NBC.