Hypocarbia during the first 24 postnatal hours and white matter echolucencies in newborns <= 28 weeks gestation

The purpose of the present study was to test the hypothesis that newborns l ess than or equal to 28 wk gestation who have a P-CO2 measurement in the lo west gestational age-specific quartile (hypocarbia) on the first day of lif e are not at increased risk for ultrasonographic white matter echolucency ( EL) after adjustment for confounders. The sample consisted of 799 infants l ess than or equal to 28 wk gestation horn during 1991-1993. Forty-eight inf ants with EL were classified as cases and compared with 751 controls, i.e, those without EL. We performed univariable comparisons, stratified analyses , and multivariable logistic regression. In the univariable analyses, hypoc arbia on the first day of life was associated with an increased EL risk. Th e odds ratios for the hypocarbia-EL relationship were prominently elevated in the strata of infants who did not have other major risk factors for EL ( e.g. gestational age 26-28 wk, normothyroxinemia, no characteristics of ant enatal infection), In the multivariable analyses, the association diminishe d after adjustment with a hypocarbia propensity score (odds ratio = 1.7; 95 % confidence interval, 0.8-3.2) or with potential confounders.