ABSTRACT
Interruption of pregnancy applies to gravidae at less than 28 full weeks’ gestation with a quiescent uterus. Practically, in the overwhelming majority of cases, abortion should be performed prior to viability or at less than 22 weeks’ gestation. The global total of legal abortions carried out each year is uncertain, but it is likely to be between 30 and 40 million. Thus, the market for safe and effective abortifacient drugs is considerable. In spite of this fact, the interest among many pharmaceutical companies in developing such drugs has been limited, mainly because of the negative attitude to abortion in general among certain population groups and organisations. Abortifacient drugs have an established clinical use for termination of second trimester pregnancy, i.e. natural prostaglandins, prostaglandin analogues, hypertonic saline, urea and rivanol, and for cervical ripening and dilatation of the cervical canal prior to vacuum aspiration in late first and early second trimester abortions, i.e. prostaglandin analogues.
