Context: High-dose estrogen treatment to reduce final height of tall girls increases their risk for infertility in later life.
Objective: The aim was to study the effect of estrogen dose on fertility outcome of these women.
Design/setting: We conducted a retrospective cohort study of university hospital patients.
Patients: We studied 125 tall women aged 20-42 yr, of whom 52 women had been treated with 100 μg and 43 with 200 μg of ethinyl estradiol (EE) in adolescence.
Main outcomes: Time to first pregnancy, treatment for infertility, and live birth rate were measured.
Results: The time to first pregnancy was increased in treated women. Of untreated women, 80% conceived within 1 yr vs. 69% of women treated with 100 μg EE and 59% of women treated with 200 μg EE. This trend of increased time to pregnancy with increasing estrogen dose was significant (log rank trend test, P = 0.01). Compared with untreated women, fecundability was reduced in women treated with both 100 μg EE [hazard ratio = 0.42; 95% confidence interval (CI), 0.19-0.95] and 200 μg EE (hazard ratio = 0.30; 95% CI, 0.13-0.72). We also observed a significant trend in the incidence of treatment for infertility with increased estrogen dose (P = 0.04). Fecundity was affected in women treated with 200 μg EE who had reduced odds of achieving at least one live birth (odds ratio = 0.13; 95% CI, 0.02-0.81), but not in women treated with 100 μg EE.
Conclusions: We report a dose-response relationship between fertility in later life and estrogen dose used for the treatment of tall stature in adolescent girls; a higher estrogen dose is associated with increased infertility.