Turner syndrome and amenorrhoea

Most females with Turner syndrome (complete or partial absence of one X chromosome) or Turner mosaic (complete or partial absence of one X chromosome in some cells) present with primary amenorrhoea, short stature and absent breast development. A small number of females begin menstruating, but subsequently develop secondary amenorrhoea.

Growth hormone supplementation is given in childhood under specialist guidance to most females with Turner syndrome. Estrogen replacement is added to induce puberty if required and to ensure adequate uterine growth and bone mineral density. Specialist guidance is required for pubertal induction and subsequent sex-hormone replacement.

After pubertal induction, the dose of estrogen is increased over 2 to 3 years to achieve adult replacement doses (with a continuous medium or high replacement dose of estrogen); a cyclical progestogen is added once breakthrough bleeding occurs, or after 2 years of estrogen therapy. A continuous progestogen may be used to avoid withdrawal bleeding. Hormone therapy should be continued until at least the age of usual menopause (median age being 51 years) unless contraindicated.

Menopausal hormone therapy (MHT) formulations are preferred to the combined oral contraceptive (COC) and the contraceptive vaginal ring, because:

• they avoid estrogen-free intervals (although continuous use of the COC or vaginal ring can also achieve this)
• progestogen is given in a more physiological formulation, especially if cyclical micronised progesterone is used
• replacement estradiol formulations may provide more bone protection than ethinylestradiol
• replacement estradiol formulations are less likely to elevate blood pressure; females with Turner syndrome have an increased risk of cardiac disorders, including aortic dilatation and dissection. COCs containing ethinylestradiol and the vaginal ring are contraindicated in females with Turner syndrome and hypertension because they may exacerbate hypertension and the risk of aortic dilatation or dissection. Data is lacking regarding the newer estradiol-containing contraceptive pills.

However, if contraception is required for individuals with regular menstruation (who usually have a mosaic form of Turner syndrome), continuous use of the combined contraceptive pill or vaginal ring is an option, provided blood pressure is normal.

If a female with Turner syndrome wishes to have children, refer to a fertility specialist.

For other aspects of Turner syndrome, see the International Turner Syndrome Consensus Group clinical practice guidelines. These include information on screening and monitoring for disorders that accompany Turner syndrome (eg thyroid dysfunction, hearing loss, heart defects, abnormal glucose metabolism, dyslipidaemia, hypertension, structural anomalies of the kidneys, diminished bone mineral density).