Rheumatic diseases have their unique pathogenesis and treatment characteristics compared to other diseases. In terms of pathogenesis, they are more frequent in women and more common in women of childbearing age, especially systemic lupus erythematosus, antiphospholipid syndrome, rheumatoid arthritis, etc. In terms of medication, they are mostly applied to hormones, immunosuppressants and other drugs that may affect the development of the fetus, so caution is needed in the use of medication during pregnancy and lactation. Although the U.S. FDA, according to the impact of drugs on the fetus, the use of drugs during pregnancy is divided into A, B, C, D, X, a total of five categories, theoretically D, X is definitely not applied during pregnancy, A, B is relatively safe, C can be applied after weighing the pros and cons of pregnant women and fetuses. However, this is only a theoretical medication reference, not quite suitable for clinical practice in the application of norms, and the level of evidence recommended is relatively low, and much of the evidence is from animal experiments, so it is necessary to develop a medication specification suitable for clinicians based on the population trial studies in recent years. 1, non-steroidal anti-inflammatory drugs (NSAIDs): in the rheumatology department is mostly used to improve joint swelling and pain in patients with rheumatic diseases, some studies have found that NSAIDs can delay ovulation in women and interfere with the process of fertilization of the egg, the latest expert opinion that female rheumatic patients during pregnancy preparation NSAIDs are prohibited. for the application of post-pregnancy, recent studies agree that early and mid-pregnancy is possible to apply NSAIDs should be discontinued in late pregnancy for the following reasons: (1) NSAIDs can inhibit the synthesis of fetal renal prostaglandins, resulting in reduced fetal urination and low amniotic fluid; (2) premature closure of the fetal ductus arteriosus, leading to the development of fetal pulmonary hypertension; (3) inhibition of uterine contractions, leading to overdue pregnancy and prolonged labor during delivery; and (4) anti-platelet aggregation, which can increase the risk of maternal hemorrhage; Therefore, it is recommended that treatment with NSAIDs should be discontinued after 30 weeks of gestation, with the exception of low-dose aspirin. Low-dose aspirin can treat obstetric antiphospholipid syndrome and can be used throughout pregnancy without increasing the risk of fetal malformations, and is generally discontinued 1 week before delivery. Some experts also believe that discontinuation of low-dose aspirin therapy is not recommended before or after delivery for patients with antiphospholipid syndrome. Studies have found that the level of NSAIDs in breast milk is very low, and that breastfeeding mothers taking NSAIDs can breastfeed and breastfeed before the next dose can reduce the infant’s exposure to NSAIDs. 2. Glucocorticoids: Hormones are divided into short-acting and long-acting types. Short-acting types include prednisone, prednisolone, methylprednisolone, etc., which can be inactivated by 11-beta dehydrogenase secreted by the placenta during the metabolic process, and only less than 10% of the active ingredients enter the fetus, suitable for the treatment of maternal diseases during pregnancy; long-acting hormones include betamethasone and dexamethasone, which are fluorinated hormones and cannot be degraded by placental enzymes and can pass through the Long-acting hormones, including betamethasone and dexamethasone, are fluorinated hormones that cannot be degraded by placental enzymes and can pass through the placenta to the fetus, making them suitable for the treatment of fetal diseases, such as single doses of long-acting hormones given from 24 to 34 weeks of gestation to treat respiratory distress syndrome. Therefore, during pregnancy we mostly use short-acting glucocorticoids to treat the primary disease. However, prolonged use during pregnancy may increase the incidence of preterm delivery, intrauterine growth retardation, gestational diabetes mellitus and gestational hypertension, so the dose of glucocorticoids should not be too high after the disease is controlled. Short-acting glucocorticosteroids can be used for breastfeeding, but when the daily dose is greater than 40 mg, it is recommended to start breastfeeding 4 hours after the dose is administered. VitD and calcium should be routinely supplemented during glucocorticoid therapy. There is still a lack of sufficient evidence for the use of bisphosphonates, so they are not recommended for use during pregnancy and lactation. Hydroxychloroquine: A large amount of trial evidence shows that hydroxychloroquine is not associated with the occurrence of fetal malformations and can be used to prevent relapse in patients with lupus, prevent thrombosis in patients with antiphospholipid syndrome and prevent the occurrence of congenital conduction block in newborns. Therefore, it is safe for use during pregnancy. The secretion in breast milk is only 0.35% of that in serum, which does not affect breastfeeding. 4. Sulfasalazine: Studies have confirmed that the use of sulfasalazine during pregnancy is not associated with fetal malformations and can be used during pregnancy, but folic acid should be supplemented at a dose of no more than 2g/d. The amount of secretion in breast milk is very low and can be given to full-term healthy infants for breastfeeding. 5. Cyclophosphamide: Studies have confirmed that cyclophosphamide has clear reproductive toxicity, and its application in women can lead to infertility and amenorrhea, the incidence of which is positively correlated with the age of the patient and the cumulative dose of the drug. The incidence of fetal malformations due to cyclophosphamide during pregnancy is about 20% and is therefore contraindicated during pregnancy and also during lactation. Cyclophosphamide should be discontinued 3 months prior to conception. 6.Methotrexate: It has obvious teratogenic effect, especially the weekly dose of ≥10mg, and it is more dangerous to use during 6-8 weeks of pregnancy. Higher dose of methotrexate can lead to the occurrence of fetal cardiac abnormalities, pulmonary hypertension and limb malformation. Since methotrexate metabolites are stored in the body for about 4 months, it is recommended to stop using this drug 4 months before pregnancy preparation and to take folic acid supplementation throughout pregnancy. Because it can be secreted into breast milk, breastfeeding is prohibited. 7, mycophenolate ester: research found that the application of early pregnancy can lead to the occurrence of congenital multiple malformations in the fetus, the probability of overall malformation of the fetus during pregnancy is about 26%, so it is prohibited in pregnancy. It should be discontinued for at least 6 weeks prior to pregnancy and strict contraception should be used while taking the drug. Lactation application data is not sufficient, and is not recommended for the time being. 8. Leflunomide: itself is an inhibitor of pyrimidine synthesis, and studies have confirmed fetal teratogenicity in animal studies, which is theoretically prohibited in pregnancy. Several case reports from 2000-2010 on whether the use of the drug during pregnancy resulted in fetal malformations showed mixed results until 2010 when the Teratogenic Information Group compared the fetal teratogenicity of 64 patients with rheumatoid arthritis exposed to leflunomide in early pregnancy with 108 patients with rheumatoid arthritis not exposed to leflunomide during pregnancy. The results showed no significant difference in fetal teratogenicity between the two groups. Subsequently, a validation trial was conducted in 45 women with rheumatic disease combined with pregnancy, and all of these enrolled cases took leflunomide within the first 2 years of pregnancy or during early pregnancy, showing that the teratogenicity of leflunomide was much less than expected. However, in view of the lack of conclusive evidence, it is still recommended that it is contraindicated during pregnancy and lactation, and for female patients who are preparing for pregnancy and taking leflunomide at the same time, they should be eluted with leflunomide before preparing for pregnancy, with the regimen of abciximide 8g, 3 times a day for 11 days. 9. Azathioprine: Most of the trial evidence about azathioprine is from patients with inflammatory bowel disease and organ transplantation. A large-scale meta-analysis showed that the application of azathioprine during pregnancy is not associated with the occurrence of congenital malformations. Therefore, azathioprine may be used to treat primary disease during pregnancy, but the dose should not exceed 2 mg/kg/d. Studies during lactation have found that azathioprine can be secreted into breast milk at approximately 0.1% of the maternal dose. Theoretically, it does not affect the development of the infant, but so far only 9 cases have been reported as safe, and the evidence is still not sufficient, so breastfeeding is not recommended. 10.Cyclosporine A: Most of the data come from patients after organ transplantation. Exposure to cyclosporine A during pregnancy is not associated with the occurrence of fetal malformations, so the lowest effective dose of cyclosporine can be used to treat maternal disease during pregnancy, and there is insufficient evidence whether breastfeeding is possible, so breastfeeding is not recommended. 11.Tacrolimus: Studies have confirmed that it is safe to apply during pregnancy, and the amount in breast milk is about 0.02% of the maternal dose, so it can be used for breastfeeding. 12.Immunoglobulin: Although it can reach the fetus through the placenta, it does not lead to malformation or immune disorders, so it is recommended for use during pregnancy and lactation. 13, Biological agents: Before 2000, there was a lack of relevant clinical data. From 2000 to 2012, the literature reported that the application of adalimumab and infliximab during pregnancy is not associated with congenital fetal malformations, but can increase the risk of neonatal infection. Etanercept theoretically suffers from the same problem. Therefore, patients should discontinue anti-TNF inhibitors as soon as possible after they know they are pregnant. If anti-TNF inhibitors are necessary during pregnancy, they should be discontinued before 30 weeks of pregnancy. The levels in breast milk are not known, so they are not recommended. Other biologics such as tolimumab, belimumab and abciap lack relevant experimental data and still need to be discontinued for 3 months before pregnancy.