By Daisuke Wakabayashi

SEATTLE (Reuters) - The parents of a severely disabled 9-year-old girl given doses of estrogen to stunt her growth and a hysterectomy to prevent menstrual cycles defended their treatment decisions as necessary for their child's quality of life.

The parents of Ashley, who cannot walk or talk and has the mental ability of a baby, made their first public statements about her treatment in a blog posting this week after her doctors detailed the growth-attenuation treatment in a medical journal in October. Ashley's last name has not been disclosed.

The treatment, which started when Ashley was six, drew criticism from other doctors and has stirred up an ethical debate about whether stopping normal life development overstepped the bounds of medical treatment.

Ashley's parents, who live in Seattle and did not disclose their names, said the effort is a more humane solution for the girl who suffers from an irreversible brain impairment called static encephalopathy.

"Ashley was dealt a challenging life and the least that we could do as her loving parents and caregivers is to be diligent about maximizing her quality of life," her parents wrote. "A fundamental and universal misconception about the treatment is that it is intended to convenience the caregiver."

High doses of estrogen should keep Ashley's height and weight near current levels at 4ft 5 in and around 75 lbs (34 kg).

"Ashley can continue to delight in being held in our arms and will be moved and taken on trips more frequently and will have more exposure to activities and social gatherings," they said.

Without the treatment, Ashley would grow to be a 5ft 6in woman weighing 125 lbs (57 kg), according to normal growth estimates.

The parents also said doctors had performed a hysterectomy so Ashley would not have to deal with discomfort related to menstrual cycles and to eliminate the possibility of uterine cancer. They also removed her breast buds to limit the development of breasts, they added.

Arthur Caplan, a medical ethicist at the University of Pennsylvania, said the "do no harm" rule governing physicians is very powerful and "stopping growth is not the ethical way to head.

David Fleming, a physician who is director of the Center for Health Ethics at the University of Missouri, said "Only history will know and only time will be able to witness whether they (the parents) made the right decision. It seems likely they were acting in the best interest of the child."

Ashley's parents started to consider this course of treatment in 2004 when she began to show early signs of puberty. Before proceeding with the surgeries or estrogen treatment, they needed to gain approval from a 40-person ethics committee at Seattle Children's Hospital.

(Additional reporting by Mike Conlon in Chicago)