Teen Estrogen Therapy May Affect Fertility
Hormone Therapy for Tall Teen Girls Found to Reduce Their Fertility
Oct. 21, 2004 -- Women who took estrogen therapy because they were tall teenagers and wanted to curb their adult height may have an unexpected consequence: fertility problems.
That's what Australian researchers found when they studied fertility among Australian women who were treated during their teen years. Now an outdated practice in many countries, many tall teens used to be treated with high doses of estrogen in the form of birth control pills. This resulted in diminished growth of bones and eventually an adult height that was less than nature had intended.
The practice has become rarer as tallness loses its social stigma for women.
"The use of estrogens to reduce the adult height of tall girls dates back to the 1950s and has been used in Europe, Australia, and the USA," write the researchers, who included Alison Venn, PhD, of the University of Tasmania in Hobart, Australia.
When given to growing teens, the therapy can reduce the final predicted adult height by around 1-4 inches (about 2 to 10 centimeters), although its effectiveness is uncertain, say the researchers.
Venn and colleagues identified medical records of more than 1,400 teens who had taken or considered height-related estrogen therapy between 1959 and 1993.
Of these, 780 women later completed the study's interviews. Of them, 371 had taken estrogen therapy as teens for treatment of tall stature and 409 had decided not to pursue the treatment.
Fertility problems were more common among the estrogen-treated women.
Almost 36% of the treatment group had tried unsuccessfully for more than a year to get pregnant, compared with about 19% of untreated women. One year of unprotected intercourse and trying to get pregnant without success defined infertility.
Women with a history of having been treated for tall stature as teens were also more likely to have taken fertility drugs and consulted a doctor for fertility concerns.
Even after taking into account the women's age (since fertility diminishes with age), treatment as teens was associated with being "less likely to have ever been pregnant, and to have ever had a live birth," write the researchers in the Oct. 23 issue of the medical journal The Lancet.
"Our findings indicate that exposure to high-dose estrogens in adolescence is associated with impaired fertility in later life," they say.
However, many of the women were eventually able to have babies, thanks to fertility treatments.
"It is reassuring that the likelihood of eventually conceiving and having a live birth was only slightly lower than that for untreated women, though treated women took longer to conceive and more required fertility services," say the researchers.