Retrograde ejaculation (retrograde ejaculation) is a condition in which there is an ejaculatory action and pleasure and orgasm during sexual intercourse, but semen is not ejaculated, but flows backwards into the bladder. It can cause male infertility. It should first be treated with standing intercourse technique, medication or surgery to restore retrograde ejaculation. If the above treatment fails, in order to solve the fertility problem then assisted reproduction can be performed by recovering sperm in the urine after ejaculation. Before recovering sperm from urine of retrograde ejaculation patients for artificial insemination, some kind of nutrient solution is usually used for multiple washes, which reduces the sperm recovery rate. In this paper, we used urine directly after ejaculation in HTF-HEPES fluid (human oviductal fluid with HEPES buffer), immediately centrifuged without washing, and directly recovered viable sperm (class a + class b) by upstream method for intrauterine insemination (IUI) successfully, and we report as follows: I. DATA AND METHODS 1. Clinical data: The patient was 30 years old, married for 4 years, diagnosed with retrograde ejaculation in an external hospital. He was diagnosed with retrograde ejaculation in a foreign hospital for 4 years, and was given herbal medicine and ephedrine, but failed to recover prograde ejaculation; later, after cystoscopy, he was diagnosed with seminiferous hyperplasia and underwent transurethral resection of the seminiferous humor, but failed to recover prograde ejaculation; he also failed to recover prograde ejaculation after standing intercourse with a full bladder. He had no history of diabetes mellitus, no history of spinal trauma, no history of bladder neck and retroperitoneal surgery, and no abnormalities on physical examination. The spouse was 27 years old, with regular menstruation and a patent fallopian tube angiogram. 2. Sperm retrieval: A low protein diet was started 1 week before insemination, 1g of sodium bicarbonate was taken orally the night before and the morning of insemination, two bottles of pure water (about 1200ml) were consumed 1 hour before insemination, the bladder was emptied twice after 1 hour, and immediately after masturbation and ejaculation, the urine was urinated in a sterile container containing 10ml of HTF-HEPES solution preheated at 37℃, and two tubes were divided and immediately centrifuged at 300g×10min. Centrifuge, discard the supernatant, add 0.5ml of HTF-HEPES solution preheated at 37℃ to each tube, and put it into the upstream of 5% CO2 incubator at 37℃ for 1 hour. 3. Ovulation monitoring and IUI: Myeloablative injection of HMG75u on days 5, 7 and 9 of the menstrual cycle, myeloablative injection of HCG10000u on day 12, and IUI on day 13 when signs of ovulation appeared, i.e. 0.5ml of upstream fluid was aspirated with a special IUI injection tube, gently placed into the uterine cavity and slowly injected, and the rest was injected into the posterior vault, with the hips elevated and supine for 1 hour. Urine HCG was tested 2 weeks after insemination, and ultrasound was performed after 6 weeks to check the presence or absence of cardiac tubular pulsation. Second, the results collected 22 ml of urine (including 10 ml of HTF-HEPES fluid), the total number of sperm 169×106 (77/10HPF), the percentage of viable sperm 54%; after upstream sperm density 68×106/ml (68/HPF), the percentage of viable sperm increased to 91%. The pregnancy was successful, and a healthy female baby was delivered by cesarean section with a birth weight of 3400g. With the increasing maturity of modern assisted reproduction technology, in order to solve the fertility problem of retrograde ejaculation patients, the sperm in urine after ejaculation can be directly recovered for assisted reproduction, and recovering a certain amount of sperm from urine and restoring and maintaining viability is the key to ensure The key to successful pregnancy is to recover a certain number of sperm from the urine and to restore and maintain viability. The former is to replace the urine by inserting a small amount of isotonic buffer before masturbating to retrieve the sperm, and then to retrieve the sperm suspension after masturbation by re-inserting the tube or emptying the bladder to retrieve the sperm suspension, this method is difficult to be accepted by patients because of the injury, infection and pain caused by intubation, and is now less commonly used. The latter method is to apply various methods to change the osmotic pressure and pH value of urine before masturbation to retrieve sperm to reduce the damage of urine to sperm, to urinate after masturbation, and to treat the urine with different cultures to recover a certain number of viable sperm. Sperm contact with urine for 5 minutes decreased viability by about 50% and caused irreversible damage if the time was prolonged; neutralizing urine PH did not protect against urine damage to sperm viability unless urine osmolality was adjusted at the same time; Kim [1] et al. pointed out that the higher the urine PH was adjusted to 7.5 and osmolality to 340 mOsm/kg, the poorer the sperm viability, and among the various nitrogenous components urinary ammonia is detrimental to sperm viability. Therefore, reducing the contact time between sperm and urine, adjusting the osmotic pressure and pH value of urine and reducing the ammonia content in urine are the keys to recovering high-quality sperm and improving the fertility rate. PH value is one of the important factors affecting sperm vitality and survival. The PH value of normal semen is 7.2-7.8, which is weakly alkaline, and normal urine is weakly acidic, with an average PH value of 6.0. Sperm are easily damaged and their vitality decreases in the weakly acidic environment of urine, but can recover if the damage is not excessive. Oral sodium bicarbonate is the most commonly used method to alkalize urine, it can improve the PH value of urine and reduce excessive damage to sperm. Vegetarians have neutral or weakly alkaline urine and have low concentrations of nitrogenous compounds in the urine. Therefore, a low-protein diet for a week in advance for fluorine patients can increase the pH of urine and reduce the concentration of urinary ammonia, reducing excessive damage to sperm. Under normal circumstances, the osmotic pressure of semen is low while the osmotic pressure of urine is high. In retrograde ejaculation patients, semen is ejected into the bladder and the high osmotic pressure of urine causes damage to the sperm membrane and decreases the vitality. The urine is diluted after drinking large amounts of water, which reduces the osmotic pressure and also dilutes the concentration of urinary ammonia, reducing excessive damage to spermatozoa. Draining urine directly into HTF-HEPES solution immediately dilutes the urine and further adjusts the pH of the urine while protecting the spermatozoa. However, each time the supernatant is centrifuged and discarded, a certain amount of sperm is lost, and the sperm suspension contains a large amount of cellular debris and dead sperm, which results in a low percentage of viable sperm and is not conducive to pregnancy. The upstream method can reduce cellular debris and dead sperm, increase the percentage of viable sperm, and at the same time, enable sperm to gain energy, which is beneficial to pregnancy. Therefore, the combined application of low-protein diet, oral sodium bicarbonate and large amount of water, emptying the bladder twice, and urinating in a sterile container with HTF-HEPES liquid immediately after ejaculation and centrifugation can reduce the contact time between sperm and urine, alkalize urine, reduce urine osmotic pressure and nitrogen content of urine and protect sperm; the direct upstream method without washing after centrifugation reduces cell debris and dead sperm and increases the percentage of viable sperm. It increases the number of viable sperm recovered, increases the percentage of viable sperm, and at the same time enables sperm to be energized and achieve a successful pregnancy. If the number of viable sperm recovered from urine is low and IUI cannot be performed, intracytoplasmic single sperm injection (ICSI) can be performed, which has been successfully reported both at home and abroad, and Jimenez [2] et al. reported that ICSI after freezing sperm recovered from urine could still result in pregnancy and a healthy baby. In the author’s opinion, the combined application of a low-protein diet, oral sodium bicarbonate, large amounts of water, urination directly into the culture after ejaculation, reduction of the number of washes and application of the upstream method can improve the number of viable sperm recovered and increase the chance of conception.