Most patients with lupus require long-term hormones and even immunosuppressive drugs to maintain remission, which is often active during pregnancy and may be exacerbated by drug withdrawal. Some drugs have definite teratogenic effects and are contraindicated in pregnancy; some drugs have potential teratogenic effects and must be weighed against the risks and benefits to the mother and fetus; many drugs have no definite teratogenic effects and can be used during pregnancy. Therefore, during pregnancy, lupus patients should use relatively safe drugs to avoid fetal malformations. (1) NSAIDs: Animal tests have shown that NSAIDs can lead to an increased incidence of fetal developmental abnormalities such as diaphragmatic hernia and ventricular septal defect. One clinical study suggested that the application of aspirin and other salicylates in the first trimester of pregnancy could increase the incidence of diaphragmatic hernia, but larger clinical studies did not reach the same conclusion. Several trials conducted in the United States and Europe with a total of 100,000 subjects have shown that aspirin (dose nonspecific) and nonselective cyclooxygenase (COX) inhibitors in the early stages of pregnancy do not increase the incidence of congenital malformations in the fetus. Therefore, the use of non-selective COX inhibitors may be continued in the early and middle stages of pregnancy. Clinical studies have shown (in more than 10,000 cases) that 60-80 mg/d aspirin in mid- to late pregnancy has no effect on fetal renal function, coagulation, pulmonary arteries, or arterial ducts. The safety of selective COX inhibitors, however, lacks strong data support and should be avoided during pregnancy. (2) Glucocorticoids: Among the hormones in various dosage forms, prednisone, prednisolone or methylprednisolone can be converted into inactive substances in the placenta, and only less than 10% of the active drug enters the fetal blood circulation, which is theoretically insufficient to produce adverse effects; betamethasone and dexamethasone are not easily metabolized by the placenta and may interfere with fetal growth and brain development. Clinical studies have shown an increased incidence of cleft lip in the offspring of those using hydrocortisone or prednisone in early pregnancy (from 0.1% to 0.3% to 0.4%), but the overall incidence is low. Overall, glucocorticoids are not considered to be teratogenic. When hormone dosage exceeds prednisone 10 mg/d, the incidence of preeclampsia, hyperemesis, gestational diabetes, infection and premature rupture of membranes may be increased. The effects of hormones on intrauterine fetal development remain controversial. High doses of hormones may lead to neonatal cataracts and adrenal suppression, so the lowest possible dose should be maintained during pregnancy. Stress doses of hydrocortisone are recommended for delivery in patients on long-term hormone use. (3) Chloroquine and hydroxychloroquine: Animal studies have shown that high doses (250 to 1500 mg/kg) of chloroquine are toxic to the fetus. Clinical studies (hundreds of subjects in total) have shown that treatment with 250 mg chloroquine or 200-400 mg hydroxychloroquine daily in early pregnancy does not increase the incidence of congenital malformations, but higher doses have a teratogenic potential. Some studies have shown that the use of hydroxychloroquine during pregnancy reduces the risk of active lupus disease. (4) Cyclophosphamide: The use of cyclophosphamide at various doses during pregnancy has been shown to be significantly teratogenic in humans and various test animals (Class III), and therefore the drug is contraindicated during pregnancy. Early gestational dosing can lead to extensive malformations of the brain, facial structures, limbs, and internal organs, while mid- and late-term dosing can cause fetal growth restriction, hematopoietic suppression, and impaired neurological development. The incidence of fetal malformation and miscarriage does not increase with pre-pregnancy use, and pregnancy is possible after 3 months of drug withdrawal. (5) Methotrexate and Leflunomide: both interfere with folic acid metabolism, affect the central nervous system and bone development, and are prohibited in pregnancy. Methotrexate can be used for pregnancy after 3 months of discontinuation; the excretion period of Leflunomide is up to 2 years due to the presence of enterohepatic circulation, and can be shortened to 6 months with the administration of kolefenamide. (6) Azathioprine: Animal studies have shown that 4 to 13 times the therapeutic dose of azathioprine can lead to fetal skeletal defects and multiple malformations; however, clinical studies have shown that azathioprine does not cause increased fetal congenital malformations and abnormal immune function in childhood. (7) Studies have shown that the fetus can develop transient asymptomatic chromosomal abnormalities, transient lymphopenia, and severe immune and myelosuppression when azathioprine is administered at doses above 2 mg/(kg・d). Therefore, azathioprine may be used during pregnancy but should not exceed the above dose (Class II). (8) Motilmicronate: An uncontrolled clinical analysis found a 26.3% miscarriage rate in pregnant patients treated with motilmicronate and a 47.6% congenital malformation rate in live births; therefore, it is contraindicated in pregnant women (Class III). The drug should be discontinued for at least 6 weeks prior to pregnancy (Class IV). (9) Cyclosporine: Animal studies have shown that cyclosporine at a dose of 10 mg/(kg・d) has no effect on the fetus, while embryotoxicity may occur at 25-100 mg/(kg・d). In clinical trials, the incidence of congenital malformations, preterm birth and low birth weight in the cyclosporine treated group did not differ from that in the general population; however, precocity and mental retardation were observed in 16% of children 1 to 12 years after birth. Therefore, the lowest effective dose of cyclosporine A (Class I) is recommended to be maintained during pregnancy. (10) Biological agents: Animal tests have not revealed embryotoxicity or teratogenicity of biological agents, but there is still a lack of data on the safety of biological agents such as anti-tumor necrosis factor antagonists and anti-CD20 antibodies for use during pregnancy, so it is recommended to discontinue such drugs before pregnancy. (11) Use during lactation: Hormones are secreted in breast milk in very small amounts, and it is safe to use moderate amounts of hormones during lactation (Class II). If the dosage is greater than 40 mg/d, it is recommended to take the drug for 4 hours before breastfeeding. There is a lack of data from studies related to dexamethasone and betamethasone. Most non-steroidal anti-inflammatory drugs, chloroquine and hydroxychloroquine, are present at low levels in breast milk, and no clear adverse effects have been observed with lactation. Cyclophosphamide is secreted in breast milk and has been reported to inhibit hematopoiesis in infants; therefore, its use during lactation is not recommended. There is no consensus on the safety of methotrexate, azathioprine and cyclosporine during lactation. The effects of leflunomide, morte-macrolide, and newer biologics in lactation are unclear.