Forced expiratory flow in uninfected infants and children born to HIV-infected mothers

The Pediatric Pulmonary and Cardiovascular Complications of Vertically Tran smitted HIV (p(2)C(2) HIV) Study is a multicenter study examining pulmonary and cardiac outcomes in offspring of HIV-infected mothers. This portion of the p(2)C(2) study tests the hypothesis that infants exposed to, but uninf ected by, maternal HIV have normal maximal expiratory flow at functional re sidual capacity (V'max,(FRC)). We obtained 500 measurements of V'max,(FRC) by rapid thoracic compression in 285 children ages 6-30 mo in five U.S. cen ters. The data were compared with those from a healthy cohort of children d escribed elsewhere. V'max,(FRC) rose with height in a linear relationship. The slope of the regression line in the exposed infants did not differ stat istically from the slope in the comparison group, but the intercept was abo ut 20% lower (p < 0.001). Height and weight were comparable in the two coho rts, and the differences between intercepts persisted after adjusting for b irth weight and gestational age. However, maternal HIV infection cannot be assumed to be the cause as the cohorts may have differed in other variables , such as socioeconomic status and frequency of maternal smoking and drug u se. Also, measurements varied substantially within and between our five cen ters, probably in part because of different racial and ethnic distributions . In summary, maternal HIV infection probably has only a modest effect, if any, on maximal expiratory flow at functional residual capacity in uninfect ed infants.