Functional Hypothalamic Amenorrhea (FHA)
What is functional hypothalamic amenorrhea?
Functional hypothalamic amenorrhea (FHA) occurs when the hypothalamus slows or stops releasing gonadotropin-releasing hormone (GnRH), a hormone that influences when a woman has a menstrual period.
FHA is associated with low body weight (defined as weighing 10 percent below ideal body weight), a low percentage of body fat, eating disorders such as anorexia nervosa or bulimia nervosa, emotional stress, strenuous exercise, and some medical conditions or illnesses. However, in some cases, there is no obvious explanation for hypothalamic amenorrhea.
What is the main concern in patients with functional hypothalamic amenorrhea?
Hypothalamic amenorrhea can lead to less estrogen production from the ovaries. Estrogen helps prevent bone loss, so if a woman lacks estrogen she may be at an increased risk for osteoporosis. Estrogen also helps to protect against heart disease.
How is functional hypothalamic amenorrhea diagnosed?
Diagnosing hypothalamic amenorrhea involves eliminating some of the other possibilities as to why a woman’s periods have stopped. For example, we will want to make sure you’re not pregnant or have another disorder that’s causing the problem. A woman’s medical history and a pelvic exam are necessary for diagnosing ovulatory dysfunction, as well as one or more of the following tests:
Hormonal Studies: These blood tests measure the levels of FSH, LH, human chorionic gonadotropin (hCG), and prolactin. Low levels of FSH and LH may indicate hypothalamic amenorrhea. High levels of prolactin may suggest a benign tumor on the pituitary gland, which can lead to amenorrhea. Human chorionic gonadotropin is a test used to confirm or eliminate the possibility of pregnancy.
Progesterone Challenge: A test that will induce menstrual bleeding (after taking progesterone) in women with certain types of amenorrhea but not in women who have hypothalamic amenorrhea.
Magnetic Resonance Imaging (MRI): A medical imaging technique that produces an image of the pituitary gland to detect a tumor or other abnormality.
How is functional hypothalamic amenorrhea treated?
Women with hypothalamic amenorrhea are sometimes able to resume normal menstrual periods after making certain lifestyle changes, such as eating a higher-calorie diet, gaining weight, reducing the intensity or frequency of exercise, and reducing emotional stress.
Low body weight and/or nutritional deficiencies: Women with eating disorders such as anorexia nervosa or bulimia often need specialized care. This usually includes nutrition counseling and work with eating disorder specialists.
Strenuous exercise: Although exercise offers many health benefits, exercising frequently or excessively can lead to amenorrhea. Studies suggest that amenorrhea develops when a woman's caloric intake is less than she burns with exercise and other daily activities. Most women with amenorrhea associated with exercise have also lost weight (resulting in a weight less than 90 percent of the ideal body weight).
For women with exercise-associated amenorrhea, treatments include increasing calorie intake and reducing the frequency and/or intensity of exercise. These measures are particularly important if a woman is trying to become pregnant. All women with amenorrhea should be sure to consume 1200 to 1500 mg of calcium daily (or take a calcium supplement) and a vitamin D supplement (400 international units, or 10 micrograms, daily).
The Endocrine Society has recommended aggressive lifestyle changes before starting a woman on hormone replacement therapy for women with hypothalamic amenorrhea. These treatments can reduce the risk of developing osteoporosis later in life.