Hypothalamus-pituitary-ovary constitutes an axis system (HPOA), the hypothalamus regulates the function of pituitary gland, pituitary gland regulates the function of ovary, and ovarian hormones then act on various target organs such as uterus, etc. At the same time, the ovarian hormones have both positive and negative feedback regulation on the hypothalamus-pituitary, etc. Normal functioning of the HPOA is one of the basic conditions for the maintenance of female reproductive function. The normal physiology of menstruation, the development and maturation of the egg, fertilization, and early embryo implantation and development are all under the control of the endocrine system and the nervous system, and depend on the normal endocrine environment in the body. The normal female ovary undergoes cyclic changes once a month. In the early follicular phase, serum follicle stimulating hormone (FSH) levels gradually increase, a group of sinusoidal follicles are recruited in the ovary, and FSH causes the granulosa cells to continue to proliferate, activating the cytochrome P450 aromatase enzyme of the granulosa cells, and promoting the synthesis and release of estradiol (E2). By day 7 of the menstrual cycle, the recruited developing follicles, with the follicle with the lowest FSH threshold, preferentially develop into the dominant follicle, which generates and secretes more E2, and feedback inhibits pituitary FSH secretion, causing the other follicles to gradually degenerate. The dominant follicle determines the duration of the follicular phase of the cycle. Serum and follicular fluid E2 levels are positively correlated with the volume of the dominant follicle. On days 11-13 of the menstrual cycle, the dominant follicle rapidly enlarges and secretes E2, reaching about 300 pg/ml (1100 pmol/L). As a result of the positive feedback effect of the E2 peak, the pituitary gland releases a large amount of luteinizing hormone (LH) and FSH, which leads to the eventual maturation of the oocyte and ovulation. After ovulation, the wall cell structure of the dominant follicle is reorganized, and the granulosa cells and follicular endothelial cells are luteinized, forming the corpus luteum and the corpus haematobium successively within 5 days after ovulation. The corpus luteum generates and secretes progesterone (P) and E2, which prepares for the reception of the pregnant egg and maintains the development of the early embryo, and the corpus luteum is most functional in the 5 to 10 days after ovulation. If the egg is not fertilized, the life span of the corpus luteum is about 14 days, and the degeneration of the corpus luteum will cause the blood E2 and P levels to drop, and the FSH level to rise, and a new ovarian cycle will begin; if the egg is fertilized and deposited, the corpus luteum will transform into the corpus luteum of pregnancy under the action of human chorionic gonadotropin (HCG), and it will degenerate only at the end of the third trimester of pregnancy. Detecting the levels of female H-P-O-A hormones is of great significance in the diagnosis of the etiology of infertility, the observation of the efficacy of treatment, the judgment of prognosis, and the study of the mechanism of action of reproductive physiology. Hormone levels are generally measured by drawing peripheral blood, and commonly used methods include radioimmunoassay and chemiluminescence. I. Requirements for the determination of 6 sex hormones 1, serum reproductive hormone test at least 1 month before the use of sex hormone drugs, to avoid affecting the test results (except for estrogen and progesterone treatment or ovulation induction therapy after the review). For those with scanty menstruation and amenorrhea, if the urine pregnancy test is negative, there is no follicle >10mm in both ovaries and the thickness of endometrium (EM) is <5mm by vaginal ultrasound, it can also be taken as the basic state.2. Examination according to the clinical needs (1) basic sex hormones: the measurement of sex hormones on 2-5 days of menstrual cycle is called basic sex hormone measurement. Basic LH, FSH, E2 measurement time should be selected from 2 to 5 days of the menstrual cycle, with the 3rd day being the best; if the cycle is shorter than 28 days, the examination time should not be longer than the 3rd day; if the cycle is more than 30 days, the examination time should not be longer than the 5th day at the latest. Prolactin (PRL) and testosterone (T) can be measured at any time of the menstrual cycle. (2) Late follicular stage (D12-16): E2, LH and P are measured when the follicle is close to maturity, to predict ovulation and the timing and dosage of HCG injections; P values are measured to estimate endometrial tolerance. (3) PRL measurement: can be measured at any time of the menstrual cycle, should be in the morning at 9 ~ 11, fasting, quiet state of the blood draw. PRL significantly elevated, a test can be determined, mildly elevated, a second examination should be carried out, can not be easily diagnosed with hyperprolactinemia (HPRL) and the abuse of bromocriptine treatment. (4) Androgens: The commonly used test indicators are serum testosterone, androstenedione and dehydroepiandrosterone sulfate. Detecting testosterone alone is of less significance, and the biochemical indicators for evaluating hyperandrogenemia mainly rely on free testosterone. (5) P: Choose luteal phase determination (D21-26 days) to understand ovulation or not and luteal function. Second, the clinical significance of the six sex hormone measurements (i) estrogen Estrogen in women of childbearing age (E) is mainly derived from the ovary, secreted by the follicle, the amount of secretion depends on the follicle's development and luteal function. In pregnant women, estrogen is mainly produced by the ovary and placenta, and to a lesser extent by the adrenal gland. In early pregnancy, E is mainly produced by the corpus luteum and is synthesized mainly by the fetal-placental unit after 10 weeks of gestation. By the end of pregnancy, E2 is 100 times greater than in nonpregnant women. Estrogen includes estradiol (E2), estrone (E1), estriol (E3). E2 is the most biologically active estrogen, one of the main hormones produced by the ovary; E3 is the degradation product of E2 and E1, with the weakest activity, and its relative ratio is 100:10:3. Estradiol test value coefficients converted: pg/ml ?3.67 = pmol/L. 1, estrogen basal value and menstrual cycle Changes (1) basic E2: E2 in the early follicular stage is at a low level, about 91.75～165.15 pmol/L (25～45pg/ml). (2) Peak E2 ovulation: E2 levels gradually increase with follicular development, with each mature follicle theoretically secreting estradiol at 918 to 1101 pmol/L (250 to 300 pg/ml). At the beginning of follicular development, the amount of E secretion is very small, and the amount of E2 secreted by the follicle increases gradually from the 7th day of menstruation, and rises rapidly to reach the first peak 1-2 days before ovulation, which is known as the peak of ovulation; the E2 can be up to 918-1835pmol/L (250-500pg/ml) before ovulation in natural cycle; the peak of E2 occurs one day before the peak of LH in most of the natural cycles, and lasts for about 48 hours at the peak of LH. It declines rapidly after ovulation. The appearance of the ovulatory peak predicts possible ovulation in about 48 hours. HCG dosage and injection time can be considered based on LH values, follicle size and cervical mucus score. (3) E2 luteal peak: E2 level decreases after ovulation, and after luteal maturation (6-8 days after LH peak), E2 rises again to form the 2nd peak, which is called the luteal peak, with a peak value of 459-918 pmol/L (125-250 pg/ml), which is about half of that of the ovulation peak. If there is no pregnancy, the E2 peak is maintained for a period of time and the P value falls at the same time, and when the corpus luteum atrophies, the E level falls sharply to the level of the early follicular phase. 2, estradiol determination of clinical significance (1) diagnosis of female precocious puberty: E2 is to determine the initiation of puberty and diagnosis of precocious puberty hormone indicators. 8 years of age before the appearance of the development of secondary sexual characteristics, blood E2 elevation > 275 pmol / L (75pg / ml) can be diagnosed as precocious puberty. (2) E1/E2 > 1 suggests increased peripheral conversion of E1 and is indirect evidence of increased testosterone (T), as in postmenopause and PCOS. (3) Excessive levels of E2 can be seen in granulosa cell tumors, plasma cystadenomas of the ovary, cirrhosis of the liver, systemic lupus erythematosus, obesity, smokers, normal pregnancies, and pregnant women with diabetes. (4) Hidden stage of premature ovarian failure: Elevated basal E2 and normal FSH are the intermediate stage between ovarian failure and normal, i.e. hidden stage of premature ovarian failure. With age and ovarian failure, there will be high FSH, LH, low E2 status. (5) Ovarian failure: lower basal E2 and higher FSH, LH, especially when FSH ≥40IU/L, suggests ovarian failure. (6) Low basal E2, FSH, LH are all low, for hypogonadotropin (Gn) deficiency, suggesting that the lesion is in the hypothalamus-pituitary gland, such as Sheehan’s syndrome. (7) Polycystic ovary syndrome: estrogen maintained at high levels without cyclic changes is an endocrine feature of polycystic ovary syndrome (PCOS), which includes elevated levels of E2 and E1, increased secretion of T and LH, and decreased secretion of FSH, with LH/FSH >2-3. (8) Early in gestation, E is mainly produced by the corpus luteum, and is synthesized by the feto-placental unit mainly after 10 weeks of gestation. By the end of pregnancy, E2 is 100 times higher than that of nonpregnant women.E2 can be used as an observational indicator of fertility preservation therapy in patients with miscarriage. (9) Predicting the effect of superovulation (COH) and pregnancy rate ①The pregnancy rate of those with basal E2 <165.2 pmol/L (45pg/ml) is significantly higher than that of those with E2 ≥165.2 pmol/L. (ii) Basal E2 > 293.6 pmol/L (80 pg/ml), regardless of age and FSH, suggests excessive follicular development and a decline in ovarian reserve function; if basal E2 > 367 pmol/L (100 pg/ml) in an IVF cycle, COH is ineffective, the cycle cancellation rate due to ovarian hypo-responsiveness or non-responsiveness is significantly increased, and the clinical pregnancy rate is decreased. (10) Indicators for monitoring follicular maturation and ovarian hyperstimulation syndrome (OHSS) ① During ovulation-promoting therapy, when follicles are ≥18 mm and blood E2 is ≥1100 pmol/L (300 pg/ml), HMG is discontinued, and HCG is injected intramuscularly with 10,000 IU. (2) When follicle maturation is achieved by ovulation-promoting therapy with E2 <3670 pmol/L (1000 pg/ml), OHSS does not usually OHSS occurs. ③ When there are more follicles developing during ovulation promotion therapy and E2＞9175pmol/L (2500pg/ml) ～11010pmol/L (3000pg/ml), it is a high-risk factor for the occurrence of OHSS. ④ When E2＞14,680pmol/L (4000pg/ml) ～22,020pmol/L during super-ovulation promotion ( 6000pg/ml), the incidence of OHSS is nearly 100% and can rapidly progress to severe OHSS. (ii) Progesterone P is secreted by the ovary, placenta, and adrenal cortex, and is mainly derived from the placenta during pregnancy. P in the peripheral blood during the menstrual cycle comes mainly from the corpus luteum formed after ovulation, and its level increases gradually with the development of the corpus luteum. During the follicular phase, P remains at a low level, averaging 0.6-1.9 nmol/L, generally <3.18 nmol/L (1ng/ml); when the LH peak occurs prior to ovulation, the granulosa cells of the mature follicle are luteinized under the action of the LH ovulatory peak, and a small amount of P is secreted, and the blood P concentration can be up to 6.36 nmol/L (2ng/ml), and the initial rise in P serves as an important reminder of the impending ovulation The initial rise in P is an important indication of impending ovulation. After ovulation, the corpus luteum forms and produces a rapid rise in P concentration; when the corpus luteum matures (6-8 days after the LH peak), the blood P concentration reaches a peak of up to 47.7-102.4nmol/L (15-32.2ng/ml) or higher. If there is no pregnancy, the corpus luteum begins to atrophy 9 to 11 days after ovulation, and the concentration of P secretion decreases abruptly, falling to follicular phase levels 4 days before menstruation. The change in blood P level throughout the luteal phase was parabolic. Progesterone test value coefficient conversion: ng/ml?3.18=nmol/L Clinical significance of P measurement: 1. Normal basal value During the whole follicular phase P value should be maintained at ＜1ng/ml, 0.9ng/ml is the minimum limit of the change of endometrial secretion phase.P value with the appearance of the peak of the LH began to rise, and the large amount of increase after ovulation. 2. Early follicular P>1ng/ml predicts poor ovulation promotion efficacy. 3.Determination of ovulation Mid luteal P＞16nmol/L (5ng/ml) suggests ovulation in this cycle (except LUFS); <16nmol/L (5ng/ml) suggests no ovulation in this cycle. 4.Diagnosis of luteal insufficiency (LPD) LPD is defined as mid-luteal P＜32nmol/L (10ng/ml), or the sum of 3 measurements of P＜95.4nmol/L (30ng/ml) on the 6th, 8th and 10th day of ovulation; on the contrary, the luteal function is normal. 5, Luteal atrophy insufficiency If P is still higher than physiological level on 4-5 days of menstruation, it suggests luteal atrophy insufficiency. 6.To determine the prognosis of in vitro fertilization-embryo transfer (IVF-ET) (1) P≥3.18nmol/L (1.0ng/ml) on the day of intramuscular injection of HCG should be regarded as elevated, which may lead to a decrease in the endothelial tolerance, and a decrease in the implantation rate of the embryo and the clinical pregnancy rate.P＞4.77nmol/L (1.5ng/ml) is likely to be prematurely luteinized. (2) In IVF-ET long protocol for ovulation, even if there is no increase in LH concentration on the day of intramuscular injection of HCG, if P (ng/ml)?1000/E2 (pg/ml) > 1, it suggests that the follicle may be luteinized prematurely, or the ovary is not functioning well, and the clinical pregnancy rate is significantly reduced. 7, pregnancy monitoring (1) P changes in pregnancy: early pregnancy P produced by the ovarian corpus luteum of pregnancy, since 8 to 10 weeks of pregnancy after the placental syncytiotrophoblast cells are the main source of P production. With the progression of pregnancy, the P value in maternal blood gradually rises, blood P value of about 79.5-89.2nmol/L (25-28.6ng/ml) at 7-8 weeks of gestation, blood P value of about 120nmol/L (38ng/ml) at 9-12 weeks of gestation, blood P value of about 144.7nmol/L (45.5ng/ml) at 13-16 weeks of gestation, blood P value of about 144.7nmol/L (45.5ng/ml) at 21-24 weeks of gestation, blood P value of about 346nmol/L (45.5ng/ml) at 21-24 weeks of gestation, blood P value of about 346nmol/L (45.5ng/ml) at 21 weeks of gestation. P value is about 346nmol/L (110.9ng/ml), to the end of pregnancy P can reach 312~624nmol/L (98~196ng/ml), 24 hours after the end of delivery P rapidly diminishes to trace amounts.P is an important observation index used for the treatment of fertility preservation of miscarriage patients. (2) Application of P in the monitoring of embryonic development: the determination of serum P concentration in early pregnancy to evaluate the luteal function and monitor the therapeutic effect of exogenous P can significantly improve the prognosis of pregnancy. Early pregnancy P levels in the range of 79.25-92.76 nmol/L (25-30 ng/ml) are suggestive of intrauterine pregnancy survival, with a sensitivity of 97.5% and a slow increase in progesterone levels with the growth of gestational weeks. Decreased P concentration in early pregnancy suggests luteal insufficiency or abnormal embryonic development, or both, but 10% of normal pregnant women have serum progesterone values below 79.25 nmol/L. P < 47.7 nmol/L (15 ng/ml) in gestation suggests a dysplastic intrauterine pregnancy or ectopic pregnancy. P level less than 15.85nmol/L (5ng/ml) during gestation suggests that the pregnancy is dead, either intrauterine or ectopic. 8, identify ectopic pregnancy Ectopic pregnancy blood P level is low, most patients P < 47.7nmol / L (15ng / ml), only 1.5% of patients ≥ 79.5nmol / L (25ng / ml). Progesterone in normal intrauterine pregnancies was >79.5nmol/L in 90% and <47.6nmol/L in 10%. Blood P levels can be used as a reference in the differential diagnosis between intrauterine and ectopic pregnancy. (iii) Measurement of FSH and LH: FSH and LH are glycoprotein hormones synthesized and secreted by basophilic Gn cells of the pituitary gland, and are jointly regulated by hypothalamic gonadotropin-releasing hormone (GnRH) and estrogen and progesterone.FSH acts on the receptors on the granulosa cells of the follicle to stimulate follicular growth, development and maturation, and to promote the secretion of estrogen.The physiological role of LH is mainly to promote ovulation and the production of the luteus and to promote the secretion of P and E by the corpus luteum. The physiological role of LH is to promote ovulation and luteinization, and to promote the secretion of P and E by the corpus luteum. In the reproductive age, the secretion of FSH and LH changes cyclically according to the menstrual cycle, FSH is slightly increased in the early follicular stage, and then in the late follicular stage, the level of oestrogen rises and FSH slightly decreases to reach the lowest level in the 24 hours before ovulation, and then rapidly rises, and then decreases in 24 hours after ovulation, and then maintains the low level in luteal phase. LH is low in the early follicular phase, then rises gradually to reach a peak about 24 hours before ovulation, then falls rapidly after 24 hours, and gradually declines in the late luteal phase. The basal values of FSH and LH are both 5-10 IU/L, which peak before ovulation, and LH peaks at 40-200 IU/L. With the exponential increase of E2 secreted in the late follicular phase, the level of LH increases 10-fold and the level of FSH increases 2-fold in 2-3 days, and ovulation usually occurs 24-36 hours after the peak of LH. Measurement of FSH and LH levels in the early follicular stage can be used to make a preliminary judgment of gonadal axis function.FSH is more valuable than LH in determining ovarian potential. Clinical significance of FSH measurement: 1. Normal basal value FSH is measured on the 1st to 3rd day of menstrual cycle to understand the reserve function and basal state of the ovary.FSH stays stable and low in the follicular phase, up to 5-10IU/L. Basal FSH is related to the quality and quantity of eggs during ovulation promotion.For the same ovulation promotion program, the higher the basal FSH, the lower the number of eggs obtained, and the lower the pregnancy rate of IVF-ET. The higher the basal FSH, the lower the number of eggs obtained and the lower the pregnancy rate of IVF-ET. 2, FSH during ovulation is about twice the basal value, not more than 30IU/L, and after ovulation, it rapidly decreases to the level of follicular phase. 3.Basal FSH and LH are <5IU/L for low Gn amenorrhea, suggesting hypothalamic or pituitary hypoplasia, and the difference between the two needs to be with the help of GnRH excitation test. It can also be seen in hyperprolactinemia, after oral contraceptives, after pharmacological pituitary regulation. 4.Basal FSH value >12～15IU/L for two consecutive cycles, suggesting ovarian dysfunction and poor ovulation therapy. Combined with CC excitation test and GnRHa excitation test, it can more accurately determine the ovarian reserve function and predict the COH effect and pregnancy rate in IVF-ET. 5.Basal FSH value >20IU/L for two consecutive cycles suggests the occult stage of premature ovarian failure and predicts possible amenorrhea after 1 year. 6.Basal FSH value >40IU/L in two consecutive cycles, LH elevation, for high Gn amenorrhea, that is, ovarian failure; if it occurs before the age of 40 years, for premature ovarian failure (POF) or ovarian insensitivity syndrome (ROS). Clinical significance of LH measurement: 1. Normal basal value 5～10IU/L, slightly lower than FSH, follicular phase to maintain a stable low value. 2, predict ovulation LH ≥ 40IU / L before ovulation, suggesting the emergence of LH peak. LH peak occurs in the E2 peak after a sudden and rapid rise, up to 3 ~ 10 times the basal value, lasted for 16 ~ 24 hours and then fell rapidly to the level of the early follicular phase. Ovulation occurs 24-36h after the blood LH peak, due to the rapid rise and fall of the LH peak, sometimes the so-called peak value is not the highest value of LH, and it needs to be detected once every 4-6h. Urine LH peak is generally later than blood LH peak 3~6h. LH combined with ultrasound, cervical scoring, etc. to predict ovulation more accurately. 3, E2 peak after LH <10IU / L, follicle >18mm, is the best time to inject HCG. 4.Follicular stage if E2 peak is not reached and LH>10IU/L, predicting LUF, LUFS. 5.Basal LH＜3IU/L suggests hypothalamic or pituitary hypoplasia. 6, the base LH level is elevated (>10IU / L is elevated) or maintain normal levels, and the base FSH is relatively low level, the formation of the LH to FSH ratio is elevated, LH / FSH> 2 ~ 3, suggesting PCOS. 7, FSH / LH> 2 ~ 3.6 suggests that the ovarian reserve function is insufficient, the patient may be poorly responsive to the COH. 8.Elevated LH often causes infertility and miscarriage in clinical practice. This is mainly due to the fact that high LH levels in the follicular phase (>10IU/L) are detrimental to both the egg embryo and the pre-implantation EM, especially since LH induces premature maturation of the oocyte, resulting in decreased fertilization ability and difficulty in implantation. (iv) Prolactin PRL is a polypeptide protein hormone synthesized and secreted by the eosinophilic PRL cells of the pituitary gland and is subject to the dual regulation of the hypothalamic prolactin-inhibiting hormone and prolactin-releasing hormone.PRL has 3 forms in the blood circulation: uni-nodal type: with a relative molecular mass of 22,000, it is known as the small-molecule prolactin, and it accounts for 80% to 90% of the blood in the circulation. Bi-nodal type: composed of 2 uni-nodal type, relative molecular mass of 50 000, accounting for 8-20%, known as macromolecular PRL. Multi-nodal type: there are multiple uni-nodal synthesized, the relative molecular weight can be greater than 100 000, accounting for 1-5%, known as large macromolecular PRL. Small molecule PRL has a higher bioactivity, and large molecule PRL has a lower ability to bind to the PRL receptor but the immunoreactivity is unaffected, the Clinically determined PRL is the sum of various forms of PRL, therefore, in some patients with elevated serum PRL in the clinic, but the reproductive function is not affected, mainly because of the high proportion of multinodal PRL in the blood circulation. Pituitary secretion of PRL is pulsatile, secretion is unstable, emotion, exercise, nipple stimulation, sexual intercourse, surgery, chest trauma, herpes zoster, hunger and eating can affect its secretion status, and with the menstrual cycle has a small fluctuation; with sleep-related rhythmicity, PRL secretion increases after sleep, secretion gradually declines after waking up in the morning, and is lowest from 9 to 11 am. Therefore, according to this rhythmic secretion characteristics, the determination of PRL should be in the morning 9 ~ 11 fasting, quiet state blood draw. For amenorrhea, infertility and menstrual disorders, PRL should be measured regardless of the presence or absence of lactation, in order to exclude hyperprolactinemia (HPRL). significantly elevated PRL can be determined by a single examination; the first examination of mildly elevated PRL should be carried out for a second examination. In established HPRL, thyroid function should be measured to exclude hypothyroidism. Prolactin test value coefficient conversion: ng/ml?44.4=nmol/L Clinical significance of PRL determination: 1, non-pregnancy PRL normal value 5～25ng/ml (222～1110nmol/ml). 2.PRL changes during pregnancy PRL begins to rise after pregnancy and gradually increases with the month of pregnancy, PRL rises about 4 times in early pregnancy than in non-pregnancy, can rise 12 times in mid-pregnancy, and can be up to 20 times in late pregnancy, about 200ng/ml or more. For those who are not breastfeeding, PRL drops to non-pregnant level in 4-6 weeks after delivery, and for those who are breastfeeding, the secretion of PRL will continue for a long period of time. 3.Elevated PRL and pituitary tumor PRL ≥25ng/ml for HPRL. PRL＞50ng/ml, about 20% have prolactinoma. PRL＞100ng/ml, about 50% have prolactinoma, optional pituitary CT or MRI. PRL >200ng/ml, microadenomas are often present, and pituitary CT or MRI must be done. In most patients, PRL levels are directly proportional to the presence or absence of a prolactinoma and its size. Serum PRL level is >150~200ng/ml, but it should be excluded when menstruation is regular. 4, PRL elevation and PCOS about 30% of PCOS patients with PRL elevation. 5, PRL elevation and thyroid function Some primary hypothyroid patients have elevated TSH, resulting in increased PRL. 6, PRL elevation and endometriosis Some patients with early endometriosis have elevated PRL. Some drugs such as chlorpromazine, antihistamines, methyldopa, rifampicin, etc. can cause elevated PRL levels, but most of them are less than 100 ng/ml. 8. PRL elevation and amenorrhea 86.7% of the time when the PRL is 101-300 ng/ml are amenorrheic. When PRL＞300ng/ml, 95.6% of patients have amenorrhea. Pituitary adenoma patients 94% amenorrhea. Certain patients with elevated PRL levels >150 to 200ng/ml without associated clinical symptoms or whose symptoms do not explain the degree of elevation need to be considered for the presence of macromolecule PRL and large macromolecule PRL. 9. Reduced PRL There are varying degrees of reduction in prolactin in Sheehan’s syndrome, and in the use of anti-PRL medications such as bromocriptine, levodopa, VitB6, and so on. (v) Testosterone In women, androgens come mainly from the adrenal glands and to a lesser extent from the ovaries. The major androgen products of the ovaries are androstenedione and testosterone. Androstenedione is synthesized and secreted mainly by follicular membrane cells; testosterone is synthesized and secreted mainly by ovarian interstitial and portal cells. Elevated androgens in the circulation prior to ovulation promote atresia of nondominant follicles on the one hand and increase libido on the other. There are four main androgens in the female circulation, namely testosterone (T), androstenedione (A), dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS).T is mainly converted from A, which is 50% from the ovary and 50% from the adrenal gland. In women, DHEA is mainly produced by the adrenal cortex. The biological activities are, in descending order, T, A, and DHEA.The androgenic activity of T is about 5 to 10 times that of A and 20 times that of DHEA. In the premenopausal period, T directly and indirectly from the ovary accounts for 2/3 of the total circulating T and indirectly from the adrenal glands accounts for 1/3 of the total, thus blood T is a marker of the ovarian androgen source. The postmenopausal adrenal gland is the main site of androgen production. During the reproductive period, there are no significant rhythmic changes in T. 98% to 99% of total T exists in bound form, and only 1% to 2% is free and active. Therefore, the measurement of free T can more accurately reflect the androgenic activity in the body than the total T. Testosterone test value coefficient conversion: ng/ml?3.47=nmol/L. Clinical significance of testosterone measurement: 1, the normal base value of women’s total T1.04-2.1nmol/L (0.3-0.6ng/ml), the upper limit of the physiology of 2.8nmol/L (0.8ng/ml); free T＜8.3nmol. T decreases with age after 35 years, but does not change significantly or even rises slightly during menopause; postmenopausal T level <1.2 nmol/L. 2, 'Precocious puberty Premature appearance of pubic and axillary hairs, accompanied by a DHEAS >1.1 umol/L (42.3ug/dl), suggesting the first appearance of adrenal function. 3. PCOS T may be normal or mildly to moderately elevated, but is usually <5.2 nmol/L (1.5 ng/ml).A may be elevated, and some patients have elevated DHEAS. If androgens are elevated before treatment and decrease after treatment, it can be used as one of the indicators to evaluate the efficacy. 4, delayed-type 21-hydroxylase deficiency T is elevated and DHEAS is elevated, while observing blood 17-hydroxyprogesterone (17-OHP) and DHEAS response of ACTH provocation test. 5.Mesenchymal - follicular membrane cell proliferative disorder T elevation, but DHEAS is normal. 6, Androgen-producing tumor Short-term progressive aggravation of hyperandrogenism symptoms, T level >5.2 nmol/L (1.5ng/ml), DHEAS level >18.9umol/L (726.92ug/dl), A >21nmol/L (600ng/dl), suggesting that there may be androgen-producing tumors in the ovary or adrenal gland. 7.Hirsutism 40%～50% of total T is elevated, and free T is almost always elevated. If the T level of female hirsutism is normal, it is considered that the hair follicles are sensitive to androgens. 8.DHEAS is the best indicator of adrenal androgen secretion, >18.2umol/L (700ug/dl) is too much. 9, T <0.02ng/ml, predicts ovarian hypofunction.