Microbial catabolism of phytosterol side chains yields C-19 steroids, C-22 steroids, and 17-ketosteroids (. precursors to adrenocortical hormones and contraceptives ).     The addition and modification of functional groups is key when producing the wide variety of medications available within this chemical classification. These modifications are performed using conventional organic synthesis and/or biotransformation techniques.  
NSAIDs are not recommended during pregnancy, particularly during the third trimester . While NSAIDs as a class are not direct teratogens , they may cause premature closure of the fetal ductus arteriosus and kidney ADRs in the fetus. Additionally, they are linked with premature birth  and miscarriage .   Aspirin, however, is used together with heparin in pregnant women with antiphospholipid antibodies .  Additionally, indomethacin is used in pregnancy to treat polyhydramnios by reducing fetal urine production via inhibiting fetal kidney blood flow.