What is the recommended starting dose of estradiol (estrogen) patch for a woman with Turner's syndrome?

Recommended Starting Dose of Estradiol Patch for Women with Turner's Syndrome

For women with Turner's syndrome, the recommended starting dose of estradiol patch is 6.25 μg/day, which can be achieved by using 1/8 of a standard patch or a 1/4 patch left in place for 3-4 days per week. 1

Age-Based Dosing Recommendations

For Adolescents (Initial Pubertal Induction)

• Start with 6.25 μg/day of transdermal estradiol at age 12-13 years if no spontaneous development and FSH is elevated 1
• Gradually increase estradiol dose at 6-12 month intervals over 2-3 years to adult dose 1
• Dose progression for transdermal estradiol:
  • 0-6 months: 1/8 of a patch weekly or 1/4 patch for 3-4 days/week 1
  • 6-12 months: 1/4 patch weekly 1
  • 12-18 months: 1/2 patch for 3-4 days, then 1/4 patch for remaining days 1
  • 18-24 months: 1/2 patch weekly 1

  • 24 months: Full patch weekly (adult dose: 100-200 μg/day) 1

For Adult Women with Turner's Syndrome

• Adult maintenance dose: 100-200 μg/day of transdermal estradiol 1
• For women diagnosed late (after age 13), estrogen may be started at somewhat higher doses and escalated more rapidly 1

Route of Administration Considerations

• Transdermal estradiol is strongly preferred over oral formulations for women with Turner's syndrome 1
• Transdermal administration provides several advantages:
  • Better uterine development parameters compared to oral ethinylestradiol 1
  • Avoids first-pass liver metabolism 1
  • More physiologic estrogen levels 2

Progestin Addition

• Begin cyclic progestogen after at least 2 years of estrogen therapy or when breakthrough bleeding occurs (typically age 14-16) 1
• Recommended progestin options:
  • Oral micronized progesterone 100-200 mg/day for 12-14 days of the month 1
  • Dydrogesterone 5-10 mg/day for 12-14 days of the month 1

Monitoring and Dose Adjustments

• Evaluate treatment effect with clinical assessment of secondary sexual characteristics and ultrasonographic evaluation of uterine volume 1
• Adjust dose based on clinical response at 6-month intervals 1, 3
• Annual clinical review once established on therapy, paying particular attention to compliance 1

Special Considerations

• For patients with Turner syndrome receiving growth hormone therapy, estradiol dose increases might be relatively slower to achieve optimal adult height 1
• Women with Turner syndrome are both estrogen and androgen deficient; conventional HRT does not fully normalize estradiol levels 2
• Low-dose estradiol treatment has been shown to improve growth rates without advancing bone age in Turner syndrome patients 4
• The lowest commercially available estradiol patches deliver 25 or 50 μg/day; dose fractionation (cutting patches) is often necessary to achieve the recommended starting dose 1

Pitfalls and Caveats

• Avoid ethinylestradiol for pubertal induction as it may lead to suboptimal uterine development 1
• Starting with too high a dose may accelerate bone age advancement and potentially reduce final height 4, 5
• Conventional HRT may increase SHBG and further decrease androgen levels in women with Turner syndrome 2
• Ensure long-term compliance as treatment should be lifelong to maintain normal bone mass 6