Infertility must know the basal sex hormone levels, first of all, choose the 2nd to 5th day of menstruation to check, and the 3rd day is the best to measure. To be sure that it is the 3rd day of menstruation, it is enough to check the 5 sex hormones, and you can not check progesterone, which should be checked during the luteal phase (21 days of menstruation or 7 days after ovulation); however, you cannot be sure whether the vaginal bleeding is menstrual or not, and you should check the 6 items to prevent misdiagnosis. In cases of scanty menstruation and amenorrhea, a negative urine pregnancy test, absence of ≥10mm follicles in both ovaries on vaginal ultrasound, and endometrial thickness of 5mm can also be done as basal status. The basal sex hormone laboratory test should be read like this: the normal values of basal LH and FSH are 5-10 IU/L, and the normal value of basal E2 is 25-50 pg/ml. The results of these 3 items should not look at the reference values on the laboratory test, but according to this standard. (a) Follicle stimulating hormone and luteinizing hormone (FSH and LH): the basal value is 5-10 IU/L In the normal menstrual cycle, the blood FSH and LH are maintained at low levels in the early follicular phase (2~3 days of menstruation) and rise rapidly before ovulation, with LH up to 3~8 times the basal value, up to 160 IU/L or even higher, while FSH is only about 2 times the basal value, rarely 30 IU/L, after ovulation After ovulation, FSH and LH rapidly return to the follicular phase level. FSH and LH levels in the early follicular phase can be monitored to determine the function of the gonadal axis, and FSH is more valuable than LH in determining ovarian potential. (ii) Progesterone (P): basal value is usually <1ng/ml. Normally, blood P during follicular phase has been at a low level, averaging 0.6~1.9nmol/L, generally <10nmol/L. When LH peak appears before ovulation, P secretion begins to increase, and after ovulation, the ovarian corpus luteum produces a large amount of P, and blood P concentration rises rapidly; when the corpus luteum matures (6~8 days after LH peak), blood P The blood P concentration reaches a peak of 47.7~102.4 nmol/L. Then it decreases continuously and reaches the lowest level in the premenstrual period. The P content of peripheral blood changes parabolically throughout the luteal phase. (iii) Estrogen (E2): the basal value is 25~45pg/ml In normal menstrual cycle, E2 is about 183.5pmol/L (50pg/ml) in early follicular phase, reaching the first peak before ovulation, up to 917.5~1835pmol/L (250~500pg), decreasing rapidly after ovulation, and forming the second peak in luteal phase, about 458.8 The luteal phase forms a second peak of about 458.8 pmol/L (124.80 pg), which is maintained for a period of time and then drops to the early follicular phase level when the corpus luteum atrophies, i.e., the 3rd day of menstruation should be 91.75-183.5 pmol/ml (25-50 pg/ml). (iv) Prolactin (PRL) PRL is synthesized and secreted by the eosinophilic PRL cells of the pituitary gland; PRL secretion is unstable, and its secretion status can be affected by emotion, exercise, sexual intercourse, hunger and eating, and there are small fluctuations with the menstrual cycle, with a rhythm related to sleep; PRL secretion increases in the short term after sleep, and rises in the afternoon compared to the morning. Therefore, according to this rhythmical secretion characteristic, blood should be drawn on an empty stomach at 9~10 a.m. If PRL is significantly elevated, it can be determined in one examination; if PRL is mildly elevated, a second examination should be performed, and hyperprolactinemia (HPRL) should not be easily diagnosed and abused with bromocriptine treatment. (E) Testosterone (T) T is mildly to moderately elevated in patients with PCOS; T is elevated in tumors with androgen-secreting ovaries or adrenal glands and in hirsutism.