Neurodevelopmental outcome of very low birth weight infants after multiple courses of antenatal corticosteroids

Antenatal corticosteroids: a risk factor for the development of chronic disease

Preterm birth remains a major health issue worldwide. Since the 1990s, women at risk for preterm birth received a single course of exogenous antenatal corticosteroids (ACSs) to facilitate fetal lung maturity. More recently, repeated or multiple courses of ACS have been supported to provide continued fetal maturity support for women with continued risk of preterm birth. However, exogenous ACS reduces birth weight which, in turn, is associated with adverse adult outcomes such as coronary heart disease, stroke, hypertension, and type 2 diabetes. The long-term effects of ACS exposure on HPA axis activity and neurological function are well documented in animal studies, and it appears that ACS, regardless of dose exposure, is capable of affecting fetal HPA axis development causing permanent changes in the HPA axis that persists through life and is manifested by chronic illness and behavioral changes. The challenge in human studies is to demonstrate whether an intervention such as ACS administration in pregnancy contributes to developmental programming and how this is manifested in later life.

The need to go beyond: evaluating antenatal corticosteroid trials with long-term outcomes

A single course of antenatal corticosteroids (ACS) reduces the risk of severe neonatal morbidity and is associated with a strong trend towards a reduced risk of abnormal neurodevelopmental outcome. However, because 50% of women given ACS remain undelivered and continue to be at risk for preterm delivery, the question remains: would these women benefit from repeated courses of ACS, and, if so, how do repeated courses of ACS affect the fetus and long-term neurodevelopmental outcome? The serious consequences of this effect on the developing brain justify the need for long-term outcome studies (beyond two years of age) before repeat courses of ACS become standard care in the management of pregnant women who are at risk of preterm delivery throughout pregnancy.