Infertility is defined as a couple of childbearing age living together after marriage, having a normal sexual life and not having conceived for 2 years without contraception. It is estimated that the rate of conception in the first year after marriage is about 90%, while the value added in two years is about 95%, so routine examination and treatment are recommended for those who have not conceived for one year. Infertility is divided into primary and secondary. Those who have never conceived after marriage without contraception are called primary infertility, while those who have had a pregnancy and then have not conceived for two consecutive years without contraception are called secondary infertility. The prevalence of infertility is about 8-10%. Although infertility is defined as not getting pregnant after one year without contraception, if a woman has a specific medical history, such as a history of chronic pelvic inflammatory disease, there is a greater chance that her fallopian tubes may be inaccessible or sticky. The diagnosis of infertility requires a comprehensive examination of both men and women to find out the causes. The following are briefly described: 1. Medical history and physical examination: Before the examination, the doctor should ask for a detailed medical history, including the history of menstruation, pregnancy and childbirth or miscarriage, sexual life, previous tuberculosis and endocrinopathy, history of surgery, what kind of infertility treatment, etc. Some basic physical and reproductive system examinations will also be performed. (1) Serological examination: follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), testosterone (T), prolactin (PRL) and progesterone (P) are present in specific cycles during the menstrual cycle. Serum FSH, LH, E2, T, and PRL are measured on the second to fourth day of menstruation. FSH >10 U/L indicates ovarian hypofunction and >40 U/L indicates premature ovarian failure. Serum P is measured one week before menstruation, if it is greater than 16nmol/L (5ng/ml), it indicates ovulation, but less than 31.8nmol/L (10ng/ml) indicates luteal insufficiency. (2) Basal body temperature (BBT): Basal body temperature fluctuates under the influence of estrogen and progesterone and is the easiest way to diagnose ovulatory function. Measure the sublingual temperature with a thermometer for 5 minutes after waking up from a deep sleep for at least 6 hours, and plot the temperature into a curve. The temperature of the ovulatory cycle is biphasic and will rise by 0.2-0.3°C for about 14 days after ovulation. (3) Ultrasound monitoring of ovulation: Ultrasound is usually performed on the second to fourth day of menstruation to exclude ovarian physiological cysts and other organic lesions and to help assess ovarian function; monitoring of ovulation begins on the ninth to tenth day to determine if follicles are developing normally. The follicles are usually larger than 18mm in diameter before ovulation and can be expelled normally. (1) Fallopian tube iodography is the most commonly used test, which is performed 3-7 days after menstruation. (2) Tubal lavage is the slow injection of saline into the uterine cavity. If there is no resistance and no reflux, it indicates patency of the fallopian tubes. Currently, tubal lavage is less used because it is more subjective and the site of tubal obstruction is not clear. (3) Laparoscopy: laparoscopy is the most accurate means to evaluate the patency of the fallopian tubes. It is performed by injecting Melan solution from the cervix and observing through the laparoscope whether the fluid flows out from the umbilical end of the fallopian tube, and also observing whether there are adhesions and micro endometriosis lesions in the pelvis, and at the same time performing treatment. Endometrial examination: Some patients may require endometrial examination, such as endometrial biopsy for those with a history of tuberculosis to exclude endometrial tuberculosis. In the past, endometrial biopsy was usually arranged within 12-24 hours of menstruation to understand ovulation and luteal function, but nowadays, the examination of ovulatory function and luteal function of the ovaries is more complete, and endometrial biopsy is no longer necessary.