Ethan Martin Crane was conceived during a drunken moment of passions between Julian and Theresa, on what they thought was their wedding night. Theresa's original plan was to pass the baby off as Ethan Winthrop's, but as soon as she realized she wasn't far enough along and Ethan would realize the truth, she planned to get an abortion, even though she had already felt the baby move for the first time. Theresa went to the abortion clinic, but despite having gone to the appointment, never went through with the abortion. She had resented him throughout her pregnancy, as soon as he was born, Theresa fell in love with her son, but denied him his father. For many months Little Ethan was at the center of a custody battle between his parents. Julian just wanted to get to know his son, but Theresa refused to let him anywhere near the baby, so Julian fought for full custody and won. He generously allowed Little Ethan to remain with his mother, even though she still refused him access.

When Little Ethan was still in diapers, Theresa went to Los Angeles for a number of weeks while Gwen and Ethan Winthrop awaited the birth of their first child. The resulting events in Los Angeles led to the death of their daughter, Sarah, and an angry and vengeful Rebecca reported Theresa to Child Protective Services as a bad mother. After an investigation into Theresa's background, Child Protective Services made the decision to take the young child from his mother and to put him in his father's custody, where he spent time primarily with Gwen and Ethan, although Julian and Rebecca were both on the fringes of his life. After Theresa attempted to kidnap Little Ethan at Julian and Rebecca's (second) wedding, Judge Reilly (who was on the Crane payroll) was horrified at seeing the traumatic effects Theresa's actions had on her child and opted to terminate her visitation.

By the time the issue came to court in the spring of 2004, Little Ethan had been used to living in the Crane mansion. Judge Sanders (who was not on the Crane payroll) initially ruled in Theresa's favor, but after seeing assault Gwen and Rebecca in the hall outside the court, Sanders opted to terminate her parental rights altogether as he did not feel she was stable enough to parent the boy. A few days later, with Julian's permission, Gwen and Ethan legally adopted Little Ethan, and his name was changed from Ethan Martin Crane to Ethan Winthrop Jr. Both Gwen and Ethan were thrilled to have him as a son, but while Gwen dreamed of a future with the boy, who was now school-aged, Ethan kept trying to think of ways to reunite Little Ethan with Theresa, even after Little Ethan made the decision to start calling Ethan and Gwen 'mommy' and 'daddy'.

Theresa finally got her wish. After a long, drawn-out saga that included kidnapping, embryo-snatching, blackmail, rape and numerous lies, Gwen and Ethan agreed to let Theresa have Little Ethan back in exchange for the child she carried. Unfortunately for Gwen, once the baby was born Theresa admitted that she had slept with Ethan (although not that she had drugged him) and that the baby she had given birth to was actually her own. Because Ethan and Gwen had already agreed to give Little Ethan to Theresa, they had no choice but to return him to her. Theresa, Little Ethan and baby Jane were not happy for long, though, because when Theresa and Ethan fought over custody of Jane in court, Theresa was once again stripped of her child, only this time her parental rights were not terminated. Determined to get both Ethan and Jane back in her life, Theresa agreed to marry Alistair Crane and allowed him to legally adopt Little Ethan, changing the boy's name from Ethan Winthrop Jr. to Ethan Lopez-Fitzgerald Crane.