CEREBRAL BLOOD-FLOW IN PRETERM INFANTS AFFECTED BY SEX, MECHANICAL VENTILATION, AND INTRAUTERINE GROWTH

Sex differences in cerebral blood flow (CBF) values have been demonstr ated in adults but not in newborns, This study evaluated the influence of sex, intrauterine growth, and need of mechanical ventilation on re sting cerebral blood flow in preterm neonates, Sixty-eight preterm inf ants with gestational ages of less than 34 weeks and birth weights of less than 1,500 gm were enrolled into the study, Cerebral blood flow w as measured by the noninvasive intravenous xenon 133 method 3 times, M easurements were classified into 3 groups: group 1: measurement at 2-3 6 hours (n = 46); group 2: measurement at 36-108 hours (n = 39); and g roup 3: measurement at 108-240 hours (n = 41). In all 3 groups, the CB F in girls was significantly lower than in boys (group 1: 11.5 +/- 2.8 ml/100 gm/min vs 14.0 +/- 4.1 ml/100 gm/min; group 2: 13.4 +/- 2.9 ml /100 gm/min vs 16.3 +/- 4.3 ml/100 gm/min; group 3: 12.9 +/- 3.2 ml/10 0 gm/min vs 15.3 +/- 3.1 ml/100 gm/min). In group 1, the CBF in neonat es requiring mechanical ventilation was significantly lower (P < .05) than in patients who were spontaneously breathing (11.5 +/- 3.7 ml/100 gm/min vs 14.2 +/- 3.1 ml/100 gm/min), and the CBF in neonates who we re too small for gestational age was significantly higher (P < .005) t han in children with appropriate intrauterine growth (16.1 +/- 4.1 ml/ 100 gm/min vs 11.5 +/- 2.6 ml/100 gm/min), It is concluded that in pre term neonates CBF is substantially affected by sex, intrauterine growt h retardation, and the need of mechanical ventilation.