This cluster of papers explores the effects of medication, particularly immunosuppressive drugs, on pregnancy outcomes, focusing on conditions such as inflammatory bowel disease, rheumatoid arthritis, and asthma. It covers topics such as medication use during pregnancy, placental transfer of drugs, impact on birth outcomes, fertility, and teratogenicity. Additionally, it delves into the management of nausea and vomiting in pregnancy and the safety of various medications for both mother and fetus.