Reactions 1405 - 9 Jun 2012

was found to be equivalent to that of term-born adultsCorticosteroids inhibit fetal growth,who were a decade older. Adults who had been exposedhave long-term CV effects to antenatal glucocorticoids also had a significantreduction in β-cell function (p = 0.01).Antenatal corticosteroids are commonly administered

The researchers of this study concluded thatto pregnant women at risk of preterm delivery, to reduce"[a]lthough antenatal glucocorticoids irrefutablythe risks of respiratory distress syndrome, perinatalimprove the survival of preterm-born infants, the impactmortality and other morbidities in the newborn. Whileon the cardiovascular system may need to be consideredthe American Congress of Obstetricians andin the longer-term care of this population when theyGynecologists (ACOG) recommends a single course ofreach adulthood."corticosteroids,1 a recent Cochrane review found that1. American College of Obstetricians and Gynecologists. Antenatal corticosteroidrepeated courses of corticosteroids were associated

therapy for fetal maturation. Committee Opinion No. 475. Obstetrics andwith further reductions in the risk of serious neonatalGynecology 117: 422-424, 1 Feb 2011.

outcomes. In contrast to this, a multinational study 2. Murphy KE, et al. Effect of Antenatal Corticosteroids on Fetal Growth andGestational Age at Birth. Obstetrics and Gynecology 119: 917-923, No. 5, Maycomparing single versus multiple courses of antenatal2012. Available from: URL: http://dx.doi.org/10.1097/aog.0b013e31825189dc.corticosteroids in women at risk for preterm birth, 3. Kelly BA, et al. Antenatal Glucocorticoid Exposure and Long-Term Alterations

shows no benefit of multiple courses over single in Aortic Function and Glucose Metabolism. Pediatrics 129: [9 pages], 16 Apr2012. Available from: URL: http://dx.doi.org/10.1542/peds.2011-3175.courses. Results from this large, placebo-controlled

801161218study, however, indicate that fetuses exposed tomultiple courses are smaller at birth.2

The Multiple Courses of Antenatal Corticosteroids forPreterm Birth Study randomised 1858 women(2304 babies) to receive either multiple courses of β-methasone or placebo, following initial receipt of asingle dose of corticosteroids. Results showed thatneonates exposed to multiple corticosteroid courses inutero weighed less, were shorter and had smaller headcircumferences compared with those whose mothersreceived placebo. A secondary analysis, conducted byresearchers from the US and Canada, determined thatthese differences were in part due to the exposed babiesbeing born at an earlier gestational age (estimateddifference -0.43 weeks; 95% CI -0.10, 0.75), and in partdue to inhibited fetal growth. After controlling forgestational age at birth and other confounding factors,multiple courses of corticosteroids continued to beassociated with a decrease in birth weight (-33.5g;-66.3, -0.73), length (-0.34cm; -0.62, -0.06) and headcircumference (-0.30cm; -0.46, -0.14). Furthermore,there was a dose-response relationship, with a trendtoward an incremental decrease in birth weight, lengthand head circumference with each additional course ofcorticosteroids.

The researchers suggest that the short-term benefitsof multiple corticosteroid courses observed in theCochrane review should be weighed up against thepossible risks of harm associated with lower birthweight; however, given no benefit was observed in thisstudy, the researchers do not recommend multiplecourses of antenatal corticosteroids.

Antenatal glucocorticoids have long-termeffects on arterial stiffness

According to a study conducted by researchers fromthe UK, antenatal glucocorticoid exposure in preterminfants is associated with long-term adverse effects onarterial stiffness and glucose metabolism when theseinfants reach adulthood.3

In this nested case-control study, 16 preterm-bornadults whose mothers had received antenatalglucocorticoids were compared with 32 term-bornparticipants whose mothers had not been exposed toglucocorticoids. Based on cardiovascular (CV) MRI dataover a 25-year follow-up period, adults who had beenexposed to glucocorticoids antenatally showed asignificantly decreased ascending aortic distensibility(p = 0.002) and an increased aortic arch pulse wavevelocity (p = 0.006). This increase in aortic arch stiffness

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