Via
AlterNet:
Any one of the three bills would be a devastating blow to reproductive health access for women in Ohio. But of the three, it is the “Heartbeat” bill that truly has the potential to change the landscape of anti-choice legislation if it passes. The bill manages to almost completely outlaw abortion in a way we have only seen before in “Personhood” amendments--such as the one that was solidly rejected twice by the voters in Colorado.
By establishing heartbeat as the criteria for banning abortion, the bill effectively rejects abortion from any point after roughly four weeks post conception, a time in which fetal heartbeat can be seen via high quality ultrasound machine. For most women, that would provide a window of two weeks or less in order to learn she was pregnant, make her decision about the pregnancy, arrange for an appointment, gather money for an abortion, obtain the mandatory counseling and sit through the required 24 hour waiting period. For a woman with irregular menstrual cycles, by the time she realizes she is pregnant it likely would already be too late to do anything but continue the pregnancy.
There are two other bills as well; however, the "Heartbeat" bill, as stated above in the quote from AlterNet, is the most severe. If a woman does not discover she is pregnant until after that four week window, her choice is essentially taken away from her as far as the law is concerned.