A 22-year-old woman comes to the office for evaluation of amenorrhea. Her last menstrual period was 5 months ago. Menarche was at age 11. The patient had regular menstrual periods up until 5 years ago when they began occurring every 2-3 months and consisted of 3 days of light bleeding. She feels fatigued and anxious, and has lost 6.8 kg (15 lb) in the past year. She has had no headaches, abnormal hair growth, loss of scalp hair, changes in peripheral vision, or hot flashes.
The patient has no chronic medical conditions and takes no medications. She does not use tobacco, alcohol, or illicit drugs. Her mother has hypothyroidism. The patient has been training for a marathon for the last 6 months and runs approximately 40 miles each week. Her diet consists mainly of high-protein bars. She is single and not sexually active.
Blood pressure is 106/78 mm Hg and pulse is 73/min. BMI is 19 kg/m². Physical examination is unremarkable.
Laboratory results are as follows:
Medroxyprogesterone acetate challenge does not produce uterine withdrawal bleeding.
Which of the following is the best next step in management of this patient?

Question

A 22-year-old woman comes to the office for evaluation of amenorrhea. Her last menstrual period was 5 months ago. Menarche was at age 11. The patient had regular menstrual periods up until 5 years ago when they began occurring every 2-3 months and consisted of 3 days of light bleeding. She feels fatigued and anxious, and has lost 6.8 kg (15 lb) in the past year. She has had no headaches, abnormal hair growth, loss of scalp hair, changes in peripheral vision, or hot flashes.
The patient has no chronic medical conditions and takes no medications. She does not use tobacco, alcohol, or illicit drugs. Her mother has hypothyroidism. The patient has been training for a marathon for the last 6 months and runs approximately 40 miles each week. Her diet consists mainly of high-protein bars. She is single and not sexually active.
Blood pressure is 106/78 mm Hg and pulse is 73/min. BMI is 19 kg/m². Physical examination is unremarkable.
Laboratory results are as follows:

Medroxyprogesterone acetate challenge does not produce uterine withdrawal bleeding.
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec193a_97df_d9b5_853d_0178f37538be_MD0002_00 Common causes of secondary amenorrhea include polycystic ovary syndrome, primary ovarian insufficiency, hypothyroidism, hyperprolactinemia, and functional hypothalamic amenorrhea (FHA). This patient has FHA, secondary amenorrhea due to relative caloric deficiency (eg, excessive exercise, weight loss, decreased intake) or stress. In these patients, the lack of hypothalamic function results in a low FSH level. The resultant estrogen deficiency, which causes a thin endometrium, is indicated by the lack of withdrawal bleeding during the medroxyprogesterone acetate challenge. Patients with FHA are at risk for stress fractures and early-onset osteoporosis secondary to low bone density. First-line treatment is lifestyle changes, including increased caloric intake, decreased exercise, stress reduction, and weight gain. The normalization of estrogen improves bone density. Combined estrogen/progestin oral contraceptives (OCPs) are second-line treatment for patients unable or unwilling to make lifestyle changes (Choice D). OCPs regulate menses and prevent bone loss; however, they mask the underlying estrogen and nutritional deficiencies. (Choice A) An MRI of the pituitary gland screens for pituitary adenoma. A pituitary adenoma (eg, prolactinoma) can cause amenorrhea; however, patients typically present with mass effects (eg, headaches, changes in peripheral vision), galactorrhea, and an elevated prolactin. This patient's prolactin is normal. (Choice B) An ultrasound of the pelvis helps to diagnose polycystic ovary syndrome, Asherman syndrome (endometrial scarring secondary to surgery or infection), and Müllerian anomalies (eg, Müllerian agenesis, uterine didelphys). However, ultrasound would not be helpful in determining this patient's diagnosis as the findings would include a thin endometrial stripe but otherwise normal anatomy. (Choice C) An ultrasound of the thyroid evaluates an enlarged thyroid (eg, goiter) or thyroid nodule. Although this patient has a family history of hypothyroidism and a slightly suppressed TSH and total T3, her free T4 is normal. These thyroid function abnormalities may be seen in patients with significant caloric restriction similar to sick euthyroid syndrome (low TSH and low thyroid hormone levels). Educational objective: Functional hypothalamic amenorrhea presents in patients with secondary amenorrhea, low FSH, and low estrogen levels secondary to relative caloric deficiency (eg, excessive exercise, weight loss). First-line treatment is with life-style changes, including decreasing exercise and increasing caloric intake. __________ References: Functional hypothalamic amenorrhea: an Endocrine Society Clinical practice guideline. (http://www.ncbi.nlm.nih.gov/pubmed/28368518)

A 22-Year-Old Woman Comes to the Office for Evaluation of Amenorrhea