Medical approaches to termination of early pregnancy.

Termination of early pregnancy by vacuum aspiration is a well-established technique. The procedure is highly effective and has a low complication rate, particularly when performed during the first few weeks after missed menses. However, this parasurgical method requires skilled health care personnel, and attempts have therefore been made to find medical alternatives. Prostaglandins were the first agents to be used successfully for this purpose, but the high incidence of mainly gastrointestinal side-effects has limited their widespread use. More recently, attention has focused on antiprogestational steroids, i.e., compounds that prevent the action of progesterone either by inhibiting its biosynthesis or by preventing it from binding to the cellular receptors in target organs. Current experience indicates that these compounds, particularly when used in combination with a low dose of a synthetic prostaglandin analogue, have the potential to become a safe, effective, and acceptable medical method for the termination of early pregnancy.