Menstrual induction: surgery versus prostaglandins.

In most developed countries in which therapeutic abortions are legal, termination of pregnancy is performed at between 8 and 12 weeks of gestation. Because the complication rate after this procedure rises with increasing gestation, there would be many advantages in inducing abortion before the eighth week ('menstrual induction'). With the increasing availability of highly sensitive methods of detecting human chorionic gonadotropin, pregnancy can now be diagnosed as early as 10-14 days after conception. The uterus can be surgically evacuated safely and simply by suction aspiration under local anaesthesia. However, a safe and effective method of inducing abortion by medical means would be a useful and cheaper alternative. Of the potentially useful compounds, only derivatives of prostaglandins E and F administered by vaginal pessary have so far been shown to be effective. Although the rate of haemorrhage and infection is low, 10-30% of women experience moderate side-effects of pelvic pain, diarrhoea and/or vomiting. The possibilities are discussed of reducing the incidence of side-effects by different methods of release or using prostaglandins in combination with other compounds such as antigestogens which might lower the therapeutic threshold.