PRETERM LABOR - A PHARMACOLOGICAL CHALLENGE

Preterm labour is a major cause of perinatal mortality and morbidity, but its prevention is difficult because most of the available drugs lack uterine selectivity and have potentially serious side-effects for the mother or the foetus. In this article, Andres Lopez Bernal and colleagues discuss new evidence that shows pregnancy is associated with changes in G protein signalling and second messenger formation in human myometrium. During gestation uterine relaxation is favoured by a pronounced increase in Ga, levels, thereby facilitating the effect of agonists that increase cAMP formation. The change in Ga, is reversed in spontaneous labour enabling the uterus to become responsive to contractile agents. Although it is not established that these changes in G protein function are causally related to the spontaneous onset of labour, nevertheless they provide a novel viewpoint towards increased understanding of the cellular mechanisms of uterine contractility, which may result in better drugs for the management of preterm labour.