Movement, imaging and neurobehavioral assessment as predictors of cerebral palsy in preterm infants.

OBJECTIVE: To study the relative efficacy of three early predictors of cerebral palsy. METHOD: One Hundred and thirty infants with birth weight <1500 g were recruited. Video recordings of spontaneous general movements were made at 36 and 52 weeks postconceptional age. Magnetic resonance imaging and the neurobehavioral assessment of the preterm infant were done at 36 weeks postconceptional age. Follow-up neurological examination and Bayley assessments were made at 18 months corrected age to make early identification of cerebral palsy. RESULTS: Magnetic resonance imaging gave the best specificity and accuracy of 91 and 84% respectively. General movements at 52 weeks showed an improved specificity and accuracy over performance at 36 weeks postconceptional age. The negative predictive value for all methods tested was between 90 and 97%. Combining the results of magnetic resonance imaging and the neurobehavioral assessment improved the sensitivity of prediction to 80%, suggesting that a holistic approach to early detection of cerebral lesions is preferable to a single test. CONCLUSIONS: The majority of infants who appeared to behave within normal limits and exhibit normal brain structure in the newborn period were classified as neurologically intact at follow-up.

Diffusion tensor brain imaging findings at term-equivalent age may predict neurologic abnormalities in low birth weight preterm infants.

BACKGROUND AND PURPOSE: Low birth weight preterm infants are at high risk of brain injury, particularly injury to the white matter. Diffusion tensor imaging is thought to be more sensitive than conventional MR imaging for detecting subtle white matter abnormalities. The objective of this study was to examine whether diffusion tensor imaging could detect abnormalities that may be associated with later neurologic abnormalities in infants with otherwise normal or minimally abnormal conventional MR imaging findings. METHODS: We prospectively studied 137 low birth weight (<1800 g) preterm infants. Neonatal conventional MR imaging and diffusion tensor imaging were performed near term-equivalent age before discharge, and neurologic development of the infants was later followed up at 18 to 24 months of age. RESULTS: Among the preterm infants who were fully studied, 63 underwent normal conventional MR imaging. Three of these infants developed cerebral palsy, and 10 others showed abnormal neurologic outcome. Diffusion tensor imaging results for these infants showed a significant reduction of fractional anisotropy in the posterior limb of the internal capsule in neurologically abnormal infants (including those with cerebral palsy) compared with control preterm infants with normal neurologic outcomes. CONCLUSION: These results suggest that neonatal diffusion tensor imaging may allow earlier detection of specific anatomic findings of microstructural abnormalities in infants at risk for neurologic abnormalities and disability. The combination of conventional MR imaging and diffusion tensor imaging may increase the predictive value of neonatal MR imaging for later neurologic outcome abnormalities and may become the basis for future interventional clinical studies to improve outcomes.

Neurodevelopmental and functional outcomes of extremely low birth weight infants in the National Institute of Child Health and Human Development Neonatal Research Network, 1993-1994.

OBJECTIVES: The purposes of this study were to report the neurodevelopmental, neurosensory, and functional outcomes of 1151 extremely low birth weight (401-1000 g) survivors cared for in the 12 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network, and to identify medical, social, and environmental factors associated with these outcomes. STUDY DESIGN: A multicenter cohort study in which surviving extremely low birth weight infants born in 1993 and 1994 underwent neurodevelopmental, neurosensory, and functional assessment at 18 to 22 months' corrected age. Data regarding pregnancy and neonatal outcome were collected prospectively. Socioeconomic status and a detailed interim medical history were obtained at the time of the assessment. Logistic regression models were used to identify maternal and neonatal risk factors for poor neurodevelopmental outcome. RESULTS: Of the 1480 infants alive at 18 months of age, 1151 (78%) were evaluated. Study characteristics included a mean birth weight of 796 +/- 135 g, mean gestation (best obstetric dates) 26 +/- 2 weeks, and 47% male. Birth weight distributions of infants included 15 infants at 401 to 500 g; 94 at 501 to 600 g; 208 at 601 to 700 g; 237 at 701 to 800 g; 290 at 801 to 900 g; and 307 at 901 to 1000 g. Twenty-five percent of the children had an abnormal neurologic examination, 37% had a Bayley II Mental Developmental Index <70, 29% had a Psychomotor Developmental Index <70, 9% had vision impairment, and 11% had hearing impairment. Neurologic, developmental, neurosensory, and functional morbidities increased with decreasing birth weight. Factors significantly associated with increased neurodevelopmental morbidity included chronic lung disease, grades 3 to 4 intraventricular hemorrhage/periventricular leukomalacia, steroids for chronic lung disease, necrotizing enterocolitis, and male gender. Factors significantly associated with decreased morbidity included increased birth weight, female gender, higher maternal education, and white race. CONCLUSION: ELBW infants are at significant risk of neurologic abnormalities, developmental delays, and functional delays at 18 to 22 months' corrected age.

Effects of skin-to-skin holding on general movements of preterm infants.

The study objective was to test the hypothesis that the effect of skin-to-skin (STS) holding increases the ratio of rest to activity in low birth weight preterm infants. Ten infants with birthweight < 2,000 grams were videotaped before and after STS holding. Video recordings were analyzed to determine the number of general movements. We found no statistically significant difference between the percentage of general movements over the two periods. We conclude that the ratio of rest-activity before and after STS holding does not change as measured by occurrence of general movements.

Neonatal severity of illness scoring systems: a comparison.

Several different scoring systems have been developed to predict neonatal morbidity and mortality. In this investigation we compared the utility of four severity of illness scoring systems (SISS) as predictors of days on ventilatory (DOV), length of hospital stay (LOS), and mortality in very-low-birth weight (VLBW) premature infants who required mechanical ventilation. The SISS assessed were the Score for Neonatal Acute Physiology (SNAP); the Score for Neonatal Acute Physiology-Perinatal Extension (SNAP + PE); Clinical Risk Index for Babies (CRIB), and the Sinkin Score at 12 hours (SS12). Results revealed significant correlations among the SS12, SNAP, SNAP + PE, CRIB, birth weight (BW), DOV, and LOS. However, none of the systems we assessed offered striking advantage over BW in a VLBW ventilated group.

Sedation administered to very low birth weight premature infants.

OBJECTIVE: The aim of this study was to evaluate the impact of individualized developmental care for very low birth weight infants on the amount of sedation used in their treatment. STUDY DESIGN: A randomized control trial was conducted. Each infant in the experimental group underwent evaluation weekly, and individualized behaviorally oriented care plans, aimed at reducing stress and promoting self-regulatory behaviors, were prepared and implemented. Control infants received the usual standard of nursery care. Total doses of opioids and chloral hydrate were calculated. Severity of illness during the initial hospital stay was stratified with use of the Neonatal Medical Index. RESULTS: Severely ill infants in the treatment group required less chloral hydrate than those in the control group. Infants who were not severely ill received little or no sedation, and among this subgroup treatment and control infants did not differ. CONCLUSIONS: We speculate that developmentally based care reduces stress levels in severely ill very low birth weight infants and thus decreases sedation requirements.

Supplemental oxygen may decrease progression of prethreshold disease to threshold retinopathy of prematurity.

The optimum level of oxygen saturation for infants with prethreshold retinopathy of prematurity (ROP) is unknown. We reviewed our conversion rate from prethreshold to threshold ROP between 1985 and 1993 during which time target levels of oxygen saturation rose in a stepwise fashion. A retrospective study of 153 infants with prethreshold ROP was performed at Stanford University between 1985 and 1993 that showed that target minimum oxygen saturation rose from 92% (1985-1987) to 95% (1988) to 96% (1989) to 99% (1990-1993). In addition, we looked at 26 infants between 1994 and 1996 who were excluded from the STOP-ROP study and who were not receiving supplemental oxygen in an effort to maintain equipoise for that study. Infant characteristics were tabulated, and rates of progression from prethreshold to threshold ROP were calculated. Rates of progression to threshold varied little between 1985 and 1989 (average 37%), but dropped to 7% for the period between 1990 and 1993. From 1994 through 1996 the rate of progression to threshold disease rose again, to 38%. Moderate supplemental oxygen (target saturation 99% with PO2 no higher than 100 mm Hg) was associated with regression of prethreshold ROP, without appearing to arrest retinal vascular maturation.

Individualized developmental care for very-low-birth-weight premature infants.

Forty very-low-birth-weight neonatal intensive care unit (NICU) infants with birth weights < or = 1,250 g were randomly assigned to treatment or control groups. Behavior of the treatment infants was systematically evaluated, and individualized developmentally oriented care plans were implemented to enhance stability. Treatment babies required fewer days of intermittent mandatory ventilation and continuous positive airway pressure and achieved full enteral feedings sooner. Length of hospital stay and hospital charges were less for treatment than control infants. There were favorable effects on treatment infants' behavioral performance at 42 weeks' postconceptional age. These results support the hypothesis that behaviorally sensitive, developmentally oriented care improves medical and neurodevelopmental outcome in the NICU.

Intracranial abnormalities and neurodevelopmental status after venovenous extracorporeal membrane oxygenation.

Computed tomography scans of the head and early neurodevelopmental assessment (Bayley Scales of Infant development) were recorded for 24 surviving infants who received venovenous extracorporeal membrane oxygenation and were compared with those of infants treated with venoarterial bypass matched by diagnosis and oxygenation index before extracorporeal membrane oxygenation. A comparable neuroradiographic and early neurodevelopmental outcome was documented for survivors of venoarterial and venovenous extracorporeal membrane oxygenation.

Lung profile: sex differences in normal pregnancy.

The incidence of respiratory distress syndrome (RDS) is higher in male than in female infants. The lung profiles--lecithin/sphingomyelin (L/S) ratios, percent disaturated (acetone precipitated) lecithin, phosphatidylglycerol, and phosphatidylinositol--were obtained in amniotic fluid during 164 normal pregnancies of 30 or more weeks' gestation. The profiles were evaluated to determine any sex differences in fetal development of the surfactant components. According to regression analysis the L/S ratios for females reached 2:1 at 33.7 weeks, which is 1.4 weeks earlier than males. A similar trend was evident for disaturated lecithin. Phosphatidylglycerol first appeared at 34 weeks' gestation for females and 35 weeks for males. The rate of the increase in phosphatidylglycerol was higher in females than in males. Phosphatidylinositol began to decrease after 36 weeks for females and fell to levels below that of males after 37 weeks' gestation. All four indexes of the lung profile revealed a higher degree of lung maturity in female than in male fetuses during the last two months of normal pregnancy. This explains a higher incidence of RDS in male than in female infants.

Husband's health and wife's labor supply.

This paper examines the labor supply response of the wife to deterioration in the husband's health. Unlike past cross-sectional studies, responses over time are directly examined through the use of longitudinal data. The empirical results suggest that the magnitude and direction of the response depend crucially on the attractiveness of transfers which the family may qualify for when the husband's health deteriorates. When no transfers are available the wife increases her market work in order to replace the lost earnings of the husband. However, as transfers become more attractive, the wife begins to reduce her labor supply, enabling her to spend more time at home caring for her husband.

Mother's home time and the production of child quality.

This paper deals with the effect of mother's time spent out of the labor force, and presumably in the home, on the "production" of child quality, where child quality is measured by intelligence (iq), level of schooling attained, and market earning power. The results indicate that mother's home time is most effective in producing (male) child quality for mothers who have attained relatively high levels of schooling. The results suggest that education programs which devote equal school resources to all (male) children do not necessarily provide equal educational opportunity and that the influence of family background on economic success is indirect, operating through home investments in children.