Inhibitors of Prostaglandin Synthesis for Treatment of Preterm Labour

Abstract

Agents which inhibit prostaglandin synthesis have been used clinically for the whole of this century [1], Yet, before 1971 it was not realised that they exerted some of their known effects through inhibition of prostaglandin synthesis [2]. When this was discovered it had already been established, although not much earlier, that prostaglandins had contractile effects on the pregnant uterus powerful enough to use them for induction of labour and termination of pregnancy [3,4]. Considering the inventiveness of obstetricians in searching for new agents to control preterm labour (Table 17.1), one would have expected that inhibitors of prostaglandin synthesis — since they were freely available — would have been applied immediately to the problem of preterm labour. This did not happen, however [5,6]. The first English language report on the use of a prostaglandin synthesis inhibitor for treatment in preterm labour appeared only in 1974 [7]. This was after a retrospective study had shown prolongation of pregnancy in chronic aspirin users [8] and after it was demonstrated that inhibitors of prostaglandin synthesis prolonged the induction-abortion interval in women undergoing second trimester abortion by hypertonic saline [9]. In 1980, inhibitors of prostaglandin synthesis were not even mentioned in a questionnaire survey by Lewis et al. [5] which reported on tocolytic agents normally used by obstetricians in the UK for treatment of preterm labour. A similar survey in the Benelux countries, reported in 1984, showed that fewer than 2% of obstetricians would use an inhibitor of prostaglandin synthesis to arrest preterm labour [6].