Milagros was brought up in an orphanage when her mother died giving birth to her.
In 1995, his acting career took off after he was castin the hit telenovela Perla Negra (Black Pearl), alongside Andrea Del Boca.
In 1996, he acted in another telenovela, named Sueltos (Loose).
His participation in Montaña Rusa, Otra Vuelta (Lets go for Another Round on the Rollercoaster) a teenager-oriented telenovela, paved the way for Arana to be chosen as Alejo in Chiquititas (Tiny Angels).
He played the lead in the fourth season of the popular show; this proved to be the highest-rated season in the show's seven-year run.
The story revolves around Milagros and Ivo, two people who fall in love with each other in spite of the odds against them.