ABSTRACT. Objective. To determine whether prenatal exposure to betamethasone for the prevention of neonatal respiratory distress syndrome (RDS) alters blood pressure in childhood.Design. Prospective follow-up study of a randomized, double-blind, placebo-controlled trial.Setting. National Women's Hospital (Auckland, New Zealand).Participants. Two hundred twenty-three 6-year-old children of mothers who presented with unplanned premature labor and took part in a randomized, controlled trial of prenatal betamethasone therapy for the prevention of neonatal RDS.Intervention. Mothers received 2 doses of betamethasone (12 mg) or placebo, administered through intramuscular injection, 24 hours apart.Main Outcome Measures. Systolic and diastolic blood pressure at 6 years of age.Results. Children exposed prenatally to betamethasone (n ‫؍‬ 121) did not differ in systolic or diastolic blood pressure from children exposed to placebo (n ‫؍‬ 102) (mean difference: systolic: ؊1.6 mm Hg; 95% confidence interval: ؊4.1 to 0.8 mm Hg; diastolic: ؊0.3 mm Hg; 95% confidence interval: ؊2.5 to 1.8 mm Hg).Conclusion. Prenatal exposure to betamethasone for prevention of neonatal RDS does not alter blood pressure at 6 years of age. Pediatrics 2004;114:e373-e377. URL: http://www.pediatrics.org/cgi/content/full/114/3/e373; prenatal glucocorticoids, respiratory distress syndrome, blood pressure, long-term follow-up.ABBREVIATIONS. RDS, respiratory distress syndrome; CI, confidence interval; RCT, randomized, controlled trial. N eonatal respiratory distress syndrome (RDS) is a major cause of early morbidity and death among the 10% of neonates who are born prematurely. Prenatal glucocorticoid therapy is recommended in the management of preterm labor, for the prevention of RDS, and is very widely used. Such prenatal use of glucocorticoids results in substantial decreases in the rates of neonatal morbidity and death, as well as considerable cost savings. However, the long-term physical effects remain poorly described. 1,2 Furthermore, fetal exposure to excess glucocorticoids has been proposed as one of the core mechanisms explaining the epidemiologic association between low birth weight and subsequent increased blood pressure (the fetal origins of adult disease hypothesis). 3 In a number of animal models, exposure to glucocorticoids before birth results in increased blood pressure in the offspring. 3,4 To date, the data on subsequent blood pressure among human subjects exposed prenatally to glucocorticoids for prevention of RDS have been contradictory. One nonrandomized cohort study found that extremely premature neonates exposed prenatally to glucocorticoids had higher blood pressure in the first 48 hours after birth. 5 Another nonrandomized cohort study of 177 fourteen-year-old children born preterm found that those exposed to glucocorticoids had higher mean systolic and diastolic blood pressures (mean difference: systolic: 4.1 mm Hg; 95% confidence interval [CI]: 0.1 to 8.0 mm Hg; diastolic: 2.8 mm Hg; 95% CI: 0.05 to 5.6 mm Hg). 6 In contrast, a ...

The mean transit time (MTT), coefficient of variation (CoV), and index of skewness (IoS) (Fish et al, 1974). The forced vital capacity (FVC) can be considered as a large number of discrete volume increments (or even gas molecules) each of which is distinguished by a transit time measured from the start ofthe expiration to a given point on the record. The distribution of transit times can be described mathematically by the mean transit-time (MTT), the coefficient of variation (CoV) of transittimes, and the index of skewness (IoS) of the transittime distribution. These are derived from the first three moments of the flow/time curve (see appendix); higher moments can be derived but add little to the description.We have compared MTT, CoV, and LoS with conventional spirographic indices in 51 asthmatic children who considered themselves free from symptoms at the time of study and in whom wheezes were not audible on auscultation. Nineteen of these children showed no abnormality of the spirogram, however analysed. In the remaining 32, abnormalities of MTT were both more frequent and of greater magnitude than those of any other index. Methods SUBJECTSThirty-five children (17 boys, 18 girls) aged between 7 and 14 years were selected from those attending a summer camp run by the Auckland Asthma Society. Sixteen children (9 boys, 7 girls) aged between 7 and 13 years were patients under the care of one of us (AL). All were Europeans and had had typical asthma since early childhood; two were not receiving any treatment at the time of study and the rest were having regular treatment with one or more of salbutamol (aerosol or tablets), disodium cromoglycate by Spinhaler, and beclomethasone aerosol. None was receiving oral steroids. Admission to the study required absence of symptoms and of clinical evidence of upper respiratory infection or wheeze. All were studied in the morning, and none had taken any medication since the previous day. PROCEDUREEach patient, after instruction and practice, made forced expirations from total lung capacity (TLC) to residual volume, in the standing position, into a calibrated Med Sci model 565 rolling-seal spirometer 194 on 12 May 2018 by guest. Protected by copyright.

Vital capacity and forced expiratory volume in 1 s were measured in 387 healthy European and 16 non-European children aged from five to 11 years. These measurements were correlated with height, sitting height, arm span, weight, lean weight and age in various combinations. Suitable linear regression equations are presented from which these lung volumes may be predicted with confidence limits down to approximately +/- 400 ml and +/- 200 ml respectively.