Low birth weight babies. Preterm and small: the obstetric challenge

Preterm labour is of unexpected origin, closely related to social class and a history of similar earlier obstetric situations. If maturity is more than 34 weeks the hazards are not great and can be comfortably cared for by paediatricians. Stopping labour can cause harm, either to the fetus which is in distress or to the mother who may not benefit from the drugs used to stop it. Thus not only can we both harm the fetus by stopping labour, even if the drugs are totally safe, but also with present methods we cannot be assured of absolute intrauterine fetal wellbeing. A decision to stop labour should therefore be confined to two groups of patients. First, the patients who would be better transferred to an appropriate intensive care neonatal unit (and there is no doubt that intrauterine transfer is preferable to extrauterine transfer because of the importance in hypoxia of the first 20 minutes). Secondly, to patients who are in preterm labour without any good cause, where the mother is totally healthy, the fetus is healthy, alive, and not at evident risk, the gestation is less than 35 weeks, the baby weighs less than 1500 g or more than 600 g, the membranes are intact, the cervix is less than 3 cm dilated, and there is no obvious intrauterine growth retardation.