Meta-analysis of the use of antibiotics in symptomatic preterm labour is dominated by the ORACLE trials. These show that administration of antibiotics to the mother do not delay delivery or improve any aspect of neonatal morbidity or mortality. The only positive health benefit is a reduction in maternal infection rates.
by experiments in which preterm labour was induced in sheep by injection of corticosteroids (Fig. 21.6). A large number of randomized trials took place during the 1970s and 1980s which, taken together, have shown that a single course of either betamethasone or dexamethasone administered to pregnant women between 24 and 34 weeks gestation up to 7 days before preterm delivery has a significant effect upon neonatal morbidity and mortality. Although the paediatric use of surfactant has had a major impact upon the incidence and consequence of respiratory distress syndrome, nevertheless antenatal corticosteroid therapy is still associated with a reduction in neonatal mortality principally due to a significant reduction in RDS and intraventricular haemorrhage rates. Antenatal corticosteroids have a receptor mediator effect on all of the components of the surfactant system in type-2 pneu-mocytes. They also, however, have effects on structural development of the lungs and lead to accelerated maturation of the fetal intestine and have effects upon the myocardium and on catecholamine responsiveness which may explain the reduced incidences of necrotizing ento-colitis and intraventricular haemorrhage seen in extremely preterm infants that appear to be independent of the effect upon RDS.
The dramatic effects of a single course of corticosteroids unfortunately led in the past to the routine prescription of multiple courses of steroids, often at weekly intervals, in women deemed to be at risk of preterm delivery, especially those with multiple pregnancies. Recent concern about the long-term consequences of recurrent exposure to high dose steroids suggesting adverse effects on development and behaviour has generally led to an abandonment of this policy. Both dexamethasone and betamethasone have been explored in randomized trials with each having similar effects on RDS rates. Studies in France suggested that betamethasone reduced the incidence of periventric-ular leukomalacia whereas dexamethasone had no such protective effect. However this may be explained by the
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The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.