Modern management of preterm labour.

Preterm birth is the leading cause of neonatal morbidity and mortality. Cervical insufficiency is not an all or nothing phenomenon but a continuous variable which can lead to preterm deliveries at different gestational ages. The relationship between shortened cervical length and spontaneous preterm birth is consistent in several studies. Shortened cervical length can be diagnosed by transvaginal ultrasonography and treated by transvaginal cervical cerclage (TCC). A nomenclature to the different stages of prevention, as primary, secondary and tertiary was suggested to facilitate comparison of studies. Apart from cervical cerclage, the most widely used tocolytics are betamimetics. Although they have been shown to delay delivery, betamimetics have not been shown to improve perinatal outcome, and they have a high frequency of unpleasant and even fatal and maternal side effects. There is growing interest in calcium channel blockers which appear to be more effective than beta-sympathomimetic drugs and have few side-effects.