Important - we don't eat cows. We eat steer. Cows have been bred over the decades and centuries to give birth and milk, not to yield meat. That's important, because some cows are heavier than their steer counterparts (Holsteins, for example).
Also very dangerous is inducing a miscarriage by taking strong medications prescribed for other ailments and many of the ways to induce a miscarriage can actually end in loss of life or other very serious consequences.
A miscarriage is the loss of pregnancy from natural causes before the 20th week of pregnancy. Most miscarriages occur very early in the pregnancy, often before a woman even knows she is pregnant. There are many different causes for a miscarriage. In most cases, there is nothing you can do to prevent a miscarriage.