The normal Menstrual period is specific performance for normal function of hypothalamic-pituitary ovarian axis. For the patients with amenorrhea, except for organ pathological changes, examination of endocrine function can help to diagnosis for Amenorrhea.
1. Progestin trial: It is detection of endogenous estrogen levels, to evaluate the in vivo estrogen levels and the integrity of the reproductive tract. Progesterone alone for test: Progesterone 20mg, once daily intramuscular injection for 5 days; or oral medroxyprogesterone acetate 10mg, once a day, and even served five days to observe whether or not withdrawal bleeding properties. Use 2 to 7 days after the emergence of drug withdrawal bleeding were positive, that development of normal reproductive tract, the existence of endometrial function has been subject to the full the role of estrogen, progesterone and thus can produce changes in secretory phase. At the same time that “gonadal axis” function basically, but without ovulation may not be perfect. Can not be negative except for the uterus and reproductive tract abnormalities, need for estrogen – progestin trial to further clarify the diagnosis of Amenorrhea.
In addition to determination of serum lactogen, if normal, may be preliminary except for pituitary tumors. If higher than normal, especially when lactation, should be held in sellar X-ray film layer to remove the tumor may be. Necessary and possible, can be used for CT examination to detect small pituitary tumor.
2. Estrogen – progesterone test: progesterone test shows negative, maybe lack of endogenous estrogen due to insufficiented endometrial stimulation and growth by estrogen. Can oral stilbestrol 1mg daily, continuous for 21 days; estradiol benzoate can also be used, every three days intramuscular injection 2mg, continuous 7 times, the last 5 days the daily intramuscular injection of progesterone 20mg. If bleeding after drug withdrawal, shows lack of estrogen levels in vivo, pathological changes site is possible in over of the ovary. No bleeding after drug withdrawal showed that in endometrial lesions.
3. Determination of pituitary gonadotropin: Estrogen withdrawal bleeding test showed positive to express low levels of estrogen in vivo, should further distinguish itself cause that due to ovarian or due to the hypothalamus – pituitary dysfunction. RIA can be used or biological determination of gonadotropin (FSH, LN) level. LH low (<5IU / L) or lack of gonadotropin synthesis and secretion, the cause may be in the pituitary or hypothalamus. FSH increased (> 40IU / L) were more interrelated with the decline of ovarian function. FSH values in the 5 ~ 30IU / L, indicate the existence of ovarian follicular.
4. Pituitary stimulation test: If gonadotropin is lower than normal, should identify lesions in the hypothalamus or pituitary. Can use gonadotropin-releasing hormone (GnRH) for Pituitary stimulation test to distinguished. Methods: Test LH, and then intravenous LHRH100µg4 hours, 15,30,60 and 120 minutes for each of the measured blood LH. Hypothalamic dysfunction, in 30 ~ 45 minutes infusion of LH increased, 60 decreased to 90 minutes, 2 to 4 hours can be increased a second time, and for about four hours. Defects of pituitary function, LH although the first rise, but it can not last long, even to continue to use, nor increase in the phenomenon of the emergence of a second meeting on the function of pituitary LH synthesis is limited. If condition that damage to the hypothalamus and pituitary are inert, the beginning of instillation had no reaction, but can occur delayed reaction about two hours.