First, the role of aspirin anti-platelet aggregation: aspirin mainly through the selective inhibition of TXA2 and PGs synthesis, thus inhibiting platelet activity, preventing microthrombosis, reducing intravascular resistance, increasing tissue perfusion, improving endometrial tolerance, and improving the outcome of ART. Second, the application of aspirin in infertility and ART: 1, in assisted reproductive technology, the addition of low-dose aspirin treatment, does not affect the clinical ovulation results and embryo quality; 2, repeated IVF failure or repeated miscarriage patients whose endometrial arteries have high resistance to blood flow and low blood flow. Small-dose aspirin (≤75mg) can reduce vascular tension, improve endometrial thickness and morphology, reduce the resistance index (RI), increase blood perfusion, and improve the rate of third-line endometrial signs. 3.Small-dose aspirin can improve endometrial dysplasia caused by clomiphene (CC) during ovulation promotion, which can significantly increase endometrial thickness and improve endometrial tolerance, thus improving the embryo implantation rate and the clinical pregnancy rate, and reducing the miscarriage rate. 4, aspirin on ACA (anticardiolipin antibodies) positive patients with therapeutic effects: a randomized controlled trial showed that: repeated IVF failure of the use of aspirin treatment, ACA-positive IVF success rate significantly increased, ACA-negative people have no significant benefit. 5, aspirin can reduce ACA-positive RSA patients 54% of the miscarriage rate, reduce fetal growth retardation, preterm labor, prenatal eclampsia incidence. Third, aspirin’s main applicable population: 1, repeated spontaneous abortion patients; 2, anticardiolipin antibody-positive patients; 3, repeated implantation failure patients; 4, previous resuscitation cycle of endothelial dysplasia patients; 5, the usual menstrual clots are more, the color of the dark red and black patients. Fourth, the contraindications of aspirin: 1, allergic to antipyretic analgesics; 2, peptic ulcer patients; 3, asthma patients; 4, pregnant women; 5, patients with severe liver damage. Use with caution: use with caution in asthma and other allergic reactions; use with caution in patients with gout. During oral intake of this drug, discomfort, please follow the doctor! Fifth, the use of aspirin: 1, IVF or ICSI line of short-acting long program, since the downgrading day of Daphne oral aspirin (75mg / day), 3 times / day, 1 tablet / times. If the pregnancy test is positive, the drug will be continued until 6 weeks after IUI/ET; if the pregnancy test is negative, the drug will be discontinued. 2.Insemination of artificial insemination (IUI), clomiphene (CC) regimen to promote ovulation, starting from the first day of menstruation, oral aspirin (75mg/day), 3 times / day, 1 tablet / times, if the pregnancy test is positive, then continue to use the drug until 6 weeks after the IUI / ET to stop the drug; pregnancy test is negative, then stop the drug. 3, menstruation dark-colored black, menstrual blood clots more, can be oral aspirin from the date of consultation, 3 times / day, 1 tablet / times, transplantation day to stop the drug. (Some patients who have failed repeated resuscitation cycles and plan to rest and recuperate at home before resuscitation or restart, they can take aspirin (75mg/day) orally 3 times/day, 1 tablet/times in the month of the week of the visit, and stop the medication if the pregnancy test is positive, and continue to use the medication until 6 weeks after IUI/ET; and stop the medication if the pregnancy test is negative). 4, the base endometrium is thin or the endometrial dysplasia in the previous cycle, HCG day endometrial thin, can be supplemented with aspirin (75mg/day) at the same time of oral supplementation of Jiale/vaginal fenmatron/pipemaxel, the daily dosage is the same as the above. 5. For patients with positive anticardiolipin antibodies, oral aspirin (75mg/day) can be taken at our center when the doctor confirms the diagnosis of this positive antibody, and the daily dosage is the same as above. Note: The aspirin mentioned in this article is enteric-soluble aspirin, with a single tablet dose of 25mg/tablet, which is available in pharmacies around the Fertility Center (because the aspirin dose at the Center is on the large side, at 100mg/tablet, which is not very convenient to take orally, it is generally recommended to buy it from outside pharmacies), and you must pay attention to the dosage of the medication when purchasing it. You can refer to the picture below, which is taken by the pharmacy. Wish you a good pregnancy!