Some herbs may directly induce miscarriage by causing the uterus to contract, including fenugreek, pleurisy root, and vervain, among others. (appliedhealth.com)
You do know that treatments for cancer or rheumatoid arthritis (to cite a couple) can also induce miscarriages? (religion.blogs.cnn.com)
Reliable research shows that the risk of an amniocentesis inducing a miscarriage is somewhere around 1 in 400 using modern methods, but some sources still use the older, scarier estimates of a 1 in 200 or even a 1 in 100 risk of miscarriage. (verywellfamily.com)