Uterine Evaluation in Turner Syndrome: A Preliminary Study With Doppler Ultrasound

Abstract

Background Since the advent of in vitro fertilization and donor ovum technology, patients with Turner syndrome, previously infertile due to ovarian failure, now have an opportunity to conceive and carry a pregnancy. This new opportunity has refocused attention on nonnal uterine growth and development in Turner syndrome. Prior studies of the uterus in Turner syndrome have utilized ultrasound measurement of the uterus to describe uterine characteristics and, in the absence of estrogen replacement therapy (ERT) or endogenous estrogen production, have found the uterine size to be almost unifonnly prepubertal irrespective of the age of the patient. No studies to date have assessed uterine blood flow by Doppler velocimetry in patients with Turner syndrome. Uterine blood flow is regulated by many factors but primarily by gonadal sex steroid hormones. In postmenopausal women on ERT a reduction in resistance to blood flow is seen. suggesting an increase in uterine perfusion with ERT. Whether this relationship is true in the patient with Turner syndrome is unknown. Methods We studied eleven patients with Turner syndrome by transabdominal pelvic ultrasound and evaluated, by Doppler velocimetty, the uterine artery pulsatility index (PI), calculated by (systolic – diastolic)/mean. Patients ranged in age from 5–17 (median 14). Pubertal development was assessed by Tanner staging, and height, weight and karyotype was recorded for all patients. Patients were placed on estrogen replacement therapy to initiate puberty, including type and dose of ERT, at the discretion of their physician. The ultrasonographer was blinded to the presence or absence of ERT. At the time of the first ultrasound, 6 patients were taking ERT, 2 on estrogen alone, 3 on cyclic estrogen/progestin (although all studies were performed on estrogen only day) and one was on an oral contraceptive. Mean duration of estrogen exposure was 23 months. One patient had spontaneous pubertal development and 4 patients had received no estrogen treatment and were Tanner I in development. At the time of ultrasound, uterine volume, cervix/fundus ratio and the presence of visible ovaries were also recorded. Results The mean uterine artery PI of patients with estrogen exposure was 2.21(± 1.23) and the mean of the unexposed group was 3.99(± 1.04). This suggests a trend toward decreased uterine artery resistance in the patients with estrogen exposure (p = 0.07 by Mann-Whitney test). The lowest PI was seen in the patient with spontaneous pubertal development. Uterine volume was significantly larger in the estrogen exposed group, 38.7 cm3 ± 23.3 in the estrogen exposed and 1.32 cm3 ± 0.9 in the non-exposed group. (p = 0.01 by Mann-Whitney test). Conclusion In the patient with Turner syndrome, estrogen exposure is associated with a corresponding increase in uterine volume and a trend toward decreased uterine artery resistance. Further study and continued prospective follow-up will indicate whether estrogen treatment in those patients studied prior to estrogen replacement is associated with similar changes.