Background: In Turner syndrome with primary ovarian failure, low-dose estrogen is started to induce puberty. Progesterone is added after breakthrough bleeding or after 2 years. In primary ovarian failure, the only source of progesterone is adrenal.

Case: A girl with Turner syndrome (45X) had primary ovarian failure since infancy. At 12 years, puberty was induced with transdermal estradiol. At 14.2 yrs, she had Tanner 3 breasts and 3 irregular periods, becoming regular with normal flow only on transdermal estradiol. Weekly serum progesterone was detectable. ACTH stimulation test increased serum progesterone from 0.27 to 1.68ng/mL at 60 mins. Regular menses continued for 16 months on transdermal estradiol without progesterone replacement.

Conclusion: Rarely, patients with Turner syndrome and primary ovarian failure experience regular menses on transdermal estradiol without progesterone replacement. Adrenal progesterone may play a role.