Effect of timing of cerebral ultrasonography on the prediction of later neurodevelopmental outcome in high-risk preterm infants.

To determine the predictive value of cranial ultrasonographic examination in high-risk preterm infants at different postnatal ages, we scanned 110 infants less than or equal to 32 weeks gestational age at 1, 2, 3, and 6 weeks postnatal ages and at 40 weeks postconceptional age (PCA). Cranial abnormalities detected by ultrasonography at each postnatal age of examination were classified as minor (periventricular superolateral echogenicity with or without intraventricular hemorrhage, grades 1 to 3) or major (cystic periventricular leukomalacia with or without intraventricular hemorrhage, grade 4) and correlated with neurodevelopmental outcome determined by 1 year of age. Major abnormalities detected by ultrasonography were present in four infants at 1 week, four at 2 weeks, eight at 3 weeks, and 11 infants at 6 weeks and 40 weeks PCA, respectively. Nineteen infants (17%) had moderate to severe functional handicaps defined as cerebral palsy, cognitive or visual deficit, or deafness. The positive and negative predictive values of ultrasound examinations, with regard to later neurodevelopmental outcome, improved with increasing postnatal age at examination and was best at 40 weeks PCA. Negative results of ultrasound study at 40 weeks PCA most correctly predicted satisfactory outcome. Although only 58% of moderately to severely handicapped infants were correctly identified by ultrasound examination at 40 weeks PCA, all infants with major ultrasonographic abnormalities at 40 weeks PCA had moderate or severe handicap. Our data demonstrate that the timing of cerebral ultrasonography is important in the prediction of later neurodevelopmental outcome in high-risk preterm infants.

Early intravenous indomethacin prolongs respiratory support in very low birth weight infants.

Infants weighing 1500 g at birth requiring either intermittent positive pressure ventilation or continuous positive airway pressure by 12 hours of age were entered in a randomized double blind controlled trial to test the efficacy of early intravenous indomethacin therapy in preventing chronic pulmonary disease of prematurity. Of the 30 newborns enrolled, 15 were treated with indomethacin and 15 were treated with placebo at 12, 24 and 36 hours of age. The groups were similar for birth weight, gestational age, sex, hyaline membrane disease and intracranial hemorrhage. Infants in the placebo group were successfully weaned from intermittent positive pressure ventilation at an earlier age than infants in the indomethacin group (p less than 0.05). Furthermore, chronic pulmonary disease of prematurity was similar in the two groups despite a reduction in the incidence of patent ductus arteriosus in the indomethacin group.

Preterm birth at 23 to 26 weeks' gestation: is active obstetric management justified?

To determine if active perinatal management was justified in preterm deliveries at less than or equal to 26 weeks' gestation, the outcome (survival and short- and long-term morbidity) of 43 infants (group I) born between 23 and 26 weeks' gestation was compared with that of 17 infants (group II) born at 27 weeks' gestation. Of the 12 surviving infants in group I (survival 28%), 11 were ventilated (median = 50 days), eight had moderate to severe bronchopulmonary dysplasia, and four had mild retrolental fibroplasia. At follow-up, two infants had physical disabilities with moderate to severe functional impairment, one had a minor disability, and nine had normal neurodevelopment. In contrast, of the 13 surviving infants in group II (survival 76%), nine were ventilated (median = 8 days), six had moderate to severe bronchopulmonary dysplasia, and six had mild RLF. At follow-up, one infant had a physical disability with moderate to severe functional impairment, four had minor disabilities, and eight had normal development. Perinatal factors that positively influenced survival in the two groups combined included active perinatal management, antenatal steroids, female sex, and absence of clinical chorioamnionitis and asphyxia. Although group I infants had a significantly higher mortality rate (p less than 0.05) and required a longer duration of ventilation (p less than 0.05), no differences in the incidence of postnatal complications or long-term morbidity at 2 to 4 years of age were evident between the two groups.

Changes in auditory brainstem responses in hyperbilirubinemic infants before and after exchange transfusion.

Auditory brainstem responses (ABR) were evoked, before and after exchange transfusion, in an effort to determine whether hyperbilirubinemia is associated with acute effects on brainstem function of neonates. Nine full-term infants with hemolytic disease received exchange transfusion for conventional serum bilirubin concentration indications (mean 22.3 +/- 1.4 mg/dL). In three infants, wave-absence before exchange transfusion was followed by appearance of the waves after exchange transfusion. Other significant alterations observed in the group after exchange transfusion were increase of wave amplitudes and reduction of interpeak latencies (brainstem transmission time 5.80 +/- 0.36 ms after exchange transfusion compared with 6.25 +/- 0.30 ms before exchange transfusion, P less than 0.001). These improvements are considered to have been brought about by removal of bilirubin from the body and from the brainstem during exchange transfusion. Acute brainstem toxicity appears to occur in a percentage of infants with hyperbilirubinemia at serum levels commonly seen in clinical practice. These changes appear to be rapidly reversible with exchange transfusion.

Periventricular infarction diagnosed by ultrasound: a postmortem correlation.

Ultrasound brain scans sometimes demonstrate increased echogenicity or cysts, or both, in the periventricular white matter, superolateral to the ventricle, in the most common site of periventricular infarction. Over 33 months, 23 preterm infants dying after 20 or more days of life were entered into this study. Superolateral echogenicity or cysts were found in 13 (57%) cases. Periventricular infarction was present at autopsy in 12 (52%) cases. Ultrasound accurately diagnosed the size, site, and extent of periventricular infarction in 78% of scans. Interpretive errors were made with poor-quality scans and with early and late studies. We conclude that sector ultrasound brain scans accurately diagnose major periventricular infarction. Hemorrhage into the site of infarction is not a prerequisite for diagnosis of periventricular infarction by ultrasound.