Objective: To investigate the effect of estrogen and progestogen on the resistance to blood flow in the uterine arteries of Turner's syndrome patients.
Design: Prospective clinical study.
Setting: A tertiary infertility clinic.
Patients: Five Turner's syndrome patients, six patients who had surgical castration, and five patients with idiopathic primary ovarian failure.
Interventions: The patients were treated with 2 mg E2 valerate to which 500 micrograms norgesterel was added for 10 days in a 28-day cycle. Transvaginal color Doppler was used to measure pulsatility index in the uterine arteries at eight regular intervals during a single cycle.
Main outcome measure: Pulsatility index of the uterine arteries.
Results: The administration of norgesterel to Turner's syndrome patients resulted in an increase in pulsatility index that was significantly higher than in patients who had surgical castration (confidence interval = 0.17 to 2.42).
Conclusion: The uterine arteries of Turner's syndrome patients are more sensitive to the tonic effect of progestogen. If manifest in cardiac arteries also this phenomenon may be partly responsible for the increased incidence of cardiovascular disease and shorter life expectancy in Turner's syndrome patients. To achieve optimal protection from cardiovascular disease, Turner's syndrome patients may benefit from hormone replacement treatment containing altered doses of estrogen and progestogen.