CHICAGO (CBS) — Teenagers as young as 14 have begun life-changing hormone therapy at Lurie Children’s Hospital to become trans men or trans women, and doctors said they’re surprised how few want to preserve their ability to become parents some day.

Hormone therapy can help a person become the person they want to be, and at some point – it’s not clear when – those hormones can take away fertility.

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So doctors at Lurie counsel teenage patients in the Gender & Sex Development Program – the ones who are on the path to trans women or trans men.

Doctors give patients in the program the option to preserve sperm or eggs now; before hormone therapy, and before it’s potentially too late.

However, only 5 percent actually went through with preserving sperm or eggs.

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“I was surprised that it was such a low percentage,” said Dr. Diane Chen, a medical psychologist at Lurie. “There is some concern of – will these young people down the line experience any regret?”

Chen said about one-third of transgender adults said they would have considered preserving fertility before their transition if they could have.

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“Is this because we are working with teenagers and young adults, for whom it is developmentally, potentially inappropriate to be thinking about having children or having families?” Chen said. “That that’s not something that a typical 15- or 16-year-old is necessarily spending a lot of time thinking about.”