Rheumatoid arthritis is a systemic autoimmune disease, mainly seen in women, so the use of drugs during pregnancy is one of the common concerns of clinicians and patients, and the drugs used by RA patients include glucocorticoids (referred to as hormones), non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs and biological agents, etc. The following is a discussion of the considerations for the use of drugs during pregnancy. Pregnant women and fetuses can tolerate hormone therapy well, and no significant adverse reactions occur. Prednisone or prednisolone is preferred for use in pregnant women because it can be metabolized by placental 11β-hydroxysteroid dehydrogenase into inactive metabolites, reducing the effect on the fetus. Intra-articular hormone injections can be used for acute exacerbation of arthritis. Patients with long-term hormone use should be treated with loading doses of prednisone during the perinatal period. Prednisolone can be used during breastfeeding, but it is recommended to breastfeed after 4h of administration to further reduce drug uptake by the infant. If NSAIDs are used after 30 weeks of gestation, they belong to class C in FDA classification and should be avoided. If they must be used, drugs with short half-life such as loxoprofen sodium should be chosen and the lowest effective dose should be used intermittently to reduce the occurrence of fetal adverse reactions. Diclofenac, flufenac, ibuprofen, indomethacin, mefenamic acid, naproxen, piroxicam and tolmetin can be used during lactation, and breastfeeding before medication can reduce infant drug uptake. C. Condition-altering antirheumatic drugs 1. Methotrexate (MTX) MTX has clear embryonic teratogenicity and belongs to Class X in the FDA drug classification, is prohibited during pregnancy and is not recommended during lactation. Since the active metabolites of MTX remain in tissue cells for several months after discontinuation, both men and women should discontinue MTX for at least 3 months prior to pregnancy and continue to take adequate folic acid supplements before and throughout pregnancy. 2. Leflunomide (LEF) LEF belongs to category X in the FDA pregnancy drug classification and is prohibited during pregnancy; the active metabolite of LEF has a long half-life, and the level of the active metabolite of the drug in the plasma decreases to less than 0.02 μg/ml only after 2 years of discontinuation, so it is necessary to discontinue the drug for 2 years before pregnancy or use abscisiclopramide elution therapy: 8 g/d in 3 doses for 11 days (not continuous) LEF can be secreted into breast milk and breastfeeding is not recommended for those taking LEF. 3.Sulfasalazine (SSZ) belongs to class B in FDA drug classification. SSZ can be secreted into breast milk, but it does not affect the health of the full-term child. Theoretically, SSZ and its metabolites can replace bilirubin and cause jaundice in newborns. 4. Azathioprine (AZA) AZA belongs to class D in FDA drug classification. AZA can also be used during lactation. 5.Cyclosporine A ( CsA ) CsA belongs to class C in the FDA drug classification. CsA can be secreted into breast milk and should be contraindicated during lactation to avoid immunosuppression in the infant. 6.Anti-malarial drugs are classified as Class C by the FDA. However, there are no further studies to confirm the definite teratogenicity, so antimalarials can be tolerated during pregnancy, and hydroxychloroquine is recommended as it has more experience than chloroquine. Although chloroquine and hydroxychloroquine can be secreted into breast milk. However, the use of hydroxychloroquine during lactation has not been found to affect the infant’s vision and hearing. Information on chloroquine is lacking. The American Academy of Pediatrics considers both drugs acceptable for use during lactation. Bisphosphonates are commonly used to prevent and treat osteoporosis caused by hormone use in patients with RA and are classified as Class C in the FDA drug classification. Maternal injection of bisphosphonates during pregnancy can cause neonatal hypocalcemia, but oral administration does not have this adverse effect. Therefore, oral administration is safer for patients who are to become pregnant. Due to the lack of long-term follow-up data for children exposed to bisphosphonates during embryonic period, it is recommended to discontinue bisphosphonates once pregnancy is detected. Abatacept is a fusion protein of cytotoxic T-lymphocyte antigen-4 and human immunoglobulin, which inhibits T-cell activation. Abatacept can pass through the placenta, and there are no animal experiments to confirm the effect of fetal malformation. However, it is not recommended for use during pregnancy and lactation due to insufficient experience with the drug. It is recommended to stop the administration of the drug for at least 10 weeks before pregnancy. Rituximab is a monoclonal antibody against CD20 on the surface of B-cells, which can pass through the placenta, resulting in the same concentration of the drug in the blood of the mother and the fetus. There is no definite conclusion whether there is any adverse effect after administration before pregnancy or early pregnancy, and the administration in the middle and late pregnancy may cause neonatal lymphocytopenia and undetectable number of B cells, so it is not recommended to be used during pregnancy and lactation, and it is recommended that both men and women should stop using rituximab for 1 year before pregnancy. 3. Tumor necrosis factor antagonists include etanercept, infliximab and adalimumab. There are no animal experiments or human prospective controlled trials to confirm that the use of TNFI during pregnancy can cause adverse consequences, and it belongs to class B in FDA drug classification. However, due to the lack of experience in using TNFI during pregnancy and the unclear long-term effects on children, TNFI should be discontinued as soon as possible after pregnancy is detected, and is not recommended during lactation. Anakinra is an IL-1 receptor antagonist, 100 mg/d subcutaneously for the treatment of moderate-to-severe RA and is classified as Class B by the FDA. It is not known whether anabolic acid is secreted in breast milk. Due to insufficient experience with the use of the drug during pregnancy and lactation, it should be discontinued after pregnancy is detected and avoided during lactation. Tocilizumab Tocilizumab is a monoclonal antibody to the IL-6 receptor and is classified as a Class C drug by the FDA.