Cerebral palsy in a term population: risk factors and neuroimaging findings

OBJECTIVE

The purpose of this work was to study risk factors and neuroimaging characteristics of cerebral palsy in term and near-term infants.

PATIENTS AND METHODS

Among a cohort of 334,339 infants > or = 36 weeks' gestation born at Kaiser Permanente Medical Care Program in northern California in 1991-2003, we identified infants with cerebral palsy and obtained clinical data from electronic and medical charts. Risk factors for cerebral palsy among infants with different brain abnormalities were compared using polytomous logistic regression.

RESULTS

Of 377 infants with cerebral palsy (prevalence: 1.1 per 1000), 273 (72%) received a head computed tomography or MRI. Abnormalities included focal arterial infarction (22%), brain malformation (14%), and periventricular white matter abnormalities (12%). Independent risk factors for cerebral palsy were maternal age > 35, black race, and intrauterine growth restriction. Intrauterine growth restriction was more strongly associated with periventricular white matter injury than with other neuroimaging findings. Nighttime delivery was associated with cerebral palsy accompanied by generalized brain atrophy but not with cerebral palsy accompanied by other brain lesions.

CONCLUSIONS

Cerebral palsy is a heterogeneous syndrome with focal arterial infarction and brain malformation representing the most common neuroimaging abnormalities in term and near-term infants. Risk factors for cerebral palsy differ depending on the type of underlying brain abnormality.

Outcomes among newborns with total serum bilirubin levels of 25 mg per deciliter or more

BACKGROUND

The neurodevelopmental risks associated with high total serum bilirubin levels in newborns are not well defined.

METHODS

We identified 140 infants with neonatal total serum bilirubin levels of at least 25 mg per deciliter (428 micromol per liter) and 419 randomly selected controls from a cohort of 106,627 term and near-term infants born from 1995 through 1998 in Kaiser Permanente hospitals in northern California. Data on outcomes were obtained from electronic records, interviews, responses to questionnaires, and neurodevelopmental evaluations that had been performed in a blinded fashion.

RESULTS

Peak bilirubin levels were between 25 and 29.9 mg per deciliter (511 micromol per liter) in 130 of the newborns with hyperbilirubinemia and 30 mg per deciliter (513 micromol per liter) or more in 10 newborns; treatment involved phototherapy in 136 cases and exchange transfusion in 5. Follow-up data to the age of at least two years were available for 132 of 140 children with a history of hyperbilirubinemia (94 percent) and 372 of 419 controls (89 percent) and included formal evaluation at a mean (+/-SD) age of 5.1+/-0.12 years for 82 children (59 percent) and 168 children (40 percent), respectively. There were no cases of kernicterus. Neither crude nor adjusted scores on cognitive tests differed significantly between the two groups; on most tests, 95 percent confidence intervals excluded a 3-point (0.2 SD) decrease in adjusted scores in the hyperbilirubinemia group. There was no significant difference between groups in the proportion of children with abnormal neurologic findings on physical examination or with documented diagnoses of neurologic abnormalities. Fourteen of the children with hyperbilirubinemia (17 percent) had "questionable" or abnormal findings on neurologic examination, as compared with 48 controls (29 percent; P=0.05; adjusted odds ratio, 0.47; 95 percent confidence interval, 0.23 to 0.98; P=0.04). The frequencies of parental concern and reported behavioral problems also were not significantly different between the two groups. Within the hyperbilirubinemia group, those with positive direct antiglobulin tests had lower scores on cognitive testing but not more neurologic or behavioral problems.

CONCLUSIONS

When treated with phototherapy or exchange transfusion, total serum bilirubin levels in the range included in this study were not associated with adverse neurodevelopmental outcomes in infants born at or near term.

Choice of Urine Collection Methods for the Diagnosis of Urinary Tract Infection in Young, Febrile Infants

BACKGROUND

The optimal method of urine collection in febrile infants is debatable; catheterization, considered more accurate, is technically difficult and invasive.

OBJECTIVES

To determine predictors of urethral catheterization in febrile infants and to compare bag and catheterized urine test performance characteristics.

DESIGN

Prospective analysis of infants enrolled in the Pediatric Research in Office Settings' Febrile Infant Study.

SETTING

A total of 219 practices from within the Pediatric Research in Office Settings' network, including 44 states, the District of Columbia, and Puerto Rico.

PATIENTS

A total of 3066 infants aged 0 to 3 months with temperatures of 38 degrees C or higher.

MAIN OUTCOME MEASURES

We calculated adjusted odds ratios for predictors of catheterization. Diagnostic test characteristics were compared between bag and catheterization. Urinary tract infection was defined as pure growth of 100 000 CFU/mL or more (bag) and 20 000 CFU/mL or more (catheterization).

RESULTS

Seventy percent of urine samples were obtained by catheterization. Predictors of catheterization included female sex, practitioner older than 40 years, Medicaid, Hispanic ethnicity, nighttime evaluation, and severe dehydration. For leukocyte esterase levels, bag specimens demonstrated no difference in sensitivity but somewhat lower specificity (84% [bag] vs 94% [catheterization], P<.001) and a lower area under the receiver operating characteristic curve for white blood cells (0.71 [bag] vs 0.86 [catheterization], P = .01). Infection rates were similar in bag and catheterized specimens (8.5% vs 10.8%). Ambiguous cultures were more common in bag specimens (7.4% vs 2.7%, P<.001), but 21 catheterized specimens are needed to avoid each ambiguous bag result.

CONCLUSIONS

Most practitioners obtain urine from febrile infants via catheterization, but choice of method is not related to the risk of urinary tract infection. Although both urine cultures and urinalyses are more accurate in catheterized specimens, the magnitude of difference is small but should be factored into clinical decision making.

Prevalence and characteristics of type 2 diabetes mellitus in 9-18 year-old children with diabetic ketoacidosis

OBJECTIVE

To estimate the prevalence of type 2 diabetes mellitus (DM2) in 9-18 year-old children with diabetic ketoacidosis (DKA) and to describe the presenting biochemical characteristics and response to standardized DKA treatment.

METHODS

Data were collected from a consecutive sample of 9-18 year-old children presenting with DKA. DKA was defined as hyperglycemia and ketosis with an initial pH <7.3, or bicarbonate <15 mmol/l. Patients were classified as having DM2 if they had negative autoantibody status and normal or elevated fasting C-peptide.

RESULTS

The prevalence of DM2 in patients with DKA was 13.0% (6.1-23.3%). There was no significant difference in the presenting pH (7.14 vs 7.15), but blood glucose was higher (735 vs 587 mg/dl) in patients with DM2, than in patients with type 1 DM (DM1). The duration of insulin infusion until resolution of acidosis (17.3 vs 13.2 h) and intensive care unit stay (2.4 vs 1.6 days) were longer in patients with DM2. Seven of the nine patients with DM2 did not require insulin at 1-year follow-up.

CONCLUSIONS

Children with DM2 can present with DKA and constitute a significant percentage in the above 9-year age group. The need for insulin must be carefully re-evaluated as DKA resolves in these patients. Adolescents with DM2 and their families need to be educated about DKA.

The Food and Drug Administration's deliberations on antidepressant use in pediatric patients

On February 2, 2004, the Food and Drug Administration organized a joint meeting of the Neuro-Psychopharmacologic Advisory Committee and Pediatric Subcommittee of the Anti-Infective Drugs Advisory Committee to examine the occurrence of suicidality in clinical trials that investigate the use of the newer antidepressant drugs in pediatric patients. Committee members reconvened on September 13-14, 2004, and concluded that there was a causal link between the newer antidepressants and pediatric suicidality. This article provides a summary of the Food and Drug Administration deliberations for the pediatric clinician. We also provide research, regulation, education, and practice implications for care for children and adolescents who may be eligible for treatment with these medications.

Neonatal hyperbilirubinemia and risk of autism spectrum disorders

OBJECTIVE

To investigate the association between neonatal hyperbilirubinemia and autism spectrum disorders (ASD).

METHODS

We conducted a large case-control study nested within the cohort of singleton term infants born between 1995 and 1998 at a northern California Kaiser Permanente hospital. Case subjects (n = 338) were children with an ASD diagnosis recorded in Kaiser Permanente outpatient databases; control subjects (n = 1817) were children without an ASD diagnosis, who were randomly sampled and frequency-matched to case subjects according to gender, birth year, and birth hospital.

RESULTS

Approximately 28% of case and control subjects received > or =1 bilirubin test in the first 30 days of life. No case-control differences were observed for maximal bilirubin levels of > or =15 mg/dL (10.1% vs 12.1%), > or =20 mg/dL (2.1% vs 2.5%), or > or =25 mg/dL (0.3% vs 0.2%). Compared with children whose maximal neonatal bilirubin levels were <15 mg/dL or not measured, children with any degree of bilirubin level elevation were not at increased risk of ASD, after adjustment for gender, birth facility, maternal age, maternal race/ethnicity, maternal education, and gestational age (for bilirubin levels of 15-19.9 mg/dL: odds ratio: 0.7; 95% confidence interval: 0.5-1.2; for bilirubin levels of 20-24.9 mg/dL: odds ratio: 0.7; 95% confidence interval: 0.3-1.6; for bilirubin levels of > or =25 mg/dL: odds ratio: 1.1; 95% confidence interval: 0.1-11.2).

CONCLUSION

These data suggest that neonatal hyperbilirubinemia is not a risk factor for ASD.

Combining Clinical Risk Factors With Serum Bilirubin Levels to Predict Hyperbilirubinemia in Newborns

OBJECTIVES

(1) To validate a previously reported risk index for predicting total serum bilirubin (TSB) levels of 25 mg/dL (428 micromol/L) or higher; (2) to combine a subset of this index with TSB levels measured at less than 48 hours to predict subsequent TSB levels of 20 mg/dL (342 micromol/L) or higher.

DESIGN

Nested case-control study using electronic and paper records (study 1). Retrospective cohort study using electronic records only (study 2).

SETTING

Northern California Kaiser Permanente hospitals.

PATIENTS

Subjects for both studies were newborns weighing 2000 g or more and of 36 weeks' or more gestation. The validation study included 67 cases born 1997-1998 who developed TSB levels of 25 mg/dL or higher at less than 30 days and 208 randomly selected control subjects. Subjects for study 2 were 5706 newborns who both were discharged from the hospital and had a TSB level measured at less than 48 hours.

RESULTS

The risk index performed similarly in the validation group, born in 1997-1998, and the derivation group, born in 1995-1996 (area under the receiver operating characteristic curve = 0.83 vs 0.84). Of the 5706 newborns with TSB levels measured before 48 hours, 270 (4.7%) developed a TSB level of 20 mg/dL or higher. Of these, 254 (94%) had a TSB level at the 75th percentile or higher at less than 48 hours. The risk index improved prediction over the TSB level alone, largely owing to the effect of gestational age. For example, for those with a TSB level at the 95th percentile or higher at less than 48 hours, the risk increased from 9% for newborns born at 40 weeks' or more gestation to 42% for those born at 36 weeks.

CONCLUSION

Clinical risk factors significantly improve prediction of subsequent hyperbilirubinemia compared with early TSB levels alone, especially in those with early TSB levels above the 75th percentile.

Richardson score predicts short-term adverse respiratory outcomes in newborns >/=34 weeks gestation

OBJECTIVES

To develop a model to predict which newborns >/=34 weeks gestation with respiratory distress will die or will require prolonged (>3 days) assisted ventilation.

METHODS

Retrospective cohort study using data from Northern California newborns >/=34 weeks gestation who presented with respiratory distress. We split the cohort into derivation and validation datasets. Bivariate and multivariate data analyses were performed on the derivation dataset. After developing a simple score on the derivation dataset, we applied it to the original as well as to a second validation dataset from Massachusetts.

RESULTS

Of 2276 babies who met our initial eligibility criteria, 203 (9.3%) had the primary study outcome (assisted ventilation >3 days or death). A simple score based on gestational age, the lowest PaO 2 /FIO 2 , a variable combining lowest pH and highest PaCO 2 , and the lowest mean arterial blood pressure had excellent performance, with a c-statistic of 0.85 in the derivation dataset, 0.80 in the validation dataset, and 0.80 in the secondary validation dataset.

CONCLUSIONS

A simple objective score based on routinely collected physiologic predictors can predict respiratory outcomes in infants >/=34 weeks gestation with respiratory distress.

Kernicterus: epidemiological strategies for its prevention through systems-based approaches

Kernicterus, thought to be due to severe hyperbilirubinemia, is an uncommon disorder with tragic consequences, especially when it affects healthy term and near-term infants. Early identification, prevention and treatment of severe hyperbilirubinemia should make kernicterus a preventable disease. However, national epidemiologic data are needed to monitor any preventive strategies. Recommendations are provided to obtain prospective data on the prevalence and incidence of severe hyperbilirubinemia and associate mortality and neurologic injury using standardized definitions, explore the clinical characteristics and root causes of kernicterus in children identified in the Kernicterus Pilot Registry, identify and test an indicator for population surveillance, validating systems-based approaches to the management of newborn jaundice, and explore the feasibility of using biologic or genetic markers to identify infants at risk for hyperbilirubinemia. Increased knowledge about the incidence and consequences of severe hyperbilirubinemia is essential to the planning, implementation and assessment of interventions to ensure that infants discharged as healthy from their birth hospitals have a safer transition to home, avoiding morbidity due to hyperbilirubinemia and other disorders. At a recent NIHCD-sponsored conference, key questions were raised about kernicterus and the need for additional strategies for its prevention. These questions and an approach to their answers form the basis of this report.

Perinatal stroke in children with motor impairment: a population-based study

OBJECTIVE

Risk factors for perinatal arterial stroke (PAS) are poorly understood. Most previous studies lack an appropriate control group and include only infants with symptoms in the newborn period. We set out to determine prenatal and perinatal risk factors for PAS.

METHODS

In a population-based, case-control study nested within the cohort of 231 582 singleton infants who were born at >or=36 weeks' gestation in Northern California Kaiser hospitals from 1991 to 1998, we searched electronically for children with motor impairment and reviewed their medical records to identify diagnoses of PAS. Control subjects were randomly selected from the study population. A medical record abstractor reviewed delivery records without knowledge of case status.

RESULTS

The prevalence of PAS with motor impairment was 17/100,000 live births. Of 38 cases, 26 (68%) presented after 3 months of age with hemiparesis or seizures. All 12 newborns with acute stroke symptoms had seizures. A delayed presentation was more common in children with moderate to severe motor impairment than among infants with only mild motor abnormalities (24 of 31 vs 2 of 7). Prepartum risk factors significantly associated with PAS in multivariate analysis were preeclampsia (odds ratio [OR]: 3.6; 95% confidence interval [CI]: 1.1-11.4) and intrauterine growth restriction (OR: 5.3; 95% CI: 1.5-18.6). Newborns with PAS were also at higher risk of delivery complications, such as emergency cesarean section (OR: 6.8; 95% CI: 2.7-16.6), 5-minute Apgar <7 (OR: 23.6; 95% CI: 4.1-237), and resuscitation at birth (OR: 4.5; 95% CI: 1.6-12.3).

CONCLUSIONS

Preeclampsia and intrauterine growth restriction (IUGR) may be independent risk factors for perinatal stroke resulting in motor impairment. Large multicenter studies that include all children with perinatal stroke are needed to determine further the risk factors and outcome of perinatal stroke.

Impact of pulse oximetry and oxygen therapy on length of stay in bronchiolitis hospitalizations

BACKGROUND

Infants hospitalized with bronchiolitis are frequently monitored with a pulse oximeter. However, there is little consensus on an acceptable lower limit of oxygenation. No previous studies have examined how the use of pulse oximetry and supplemental oxygen therapy affects length of stay.

OBJECTIVE

To determine the extent to which bronchiolitis hospitalizations are prolonged by a perceived need for supplemental oxygen based on pulse oximetry readings. Design and Patients Retrospective case series of subjects younger than 2 years who were hospitalized with bronchiolitis at an academic medical center. Two investigators independently reviewed the hospitalization records of 73 infants and determined at what point an infant met all discharge criteria except oxygenation. We then calculated the extent to which hospitalizations were prolonged by a perceived need for supplemental oxygen therapy based on pulse oximetry readings alone.

RESULTS

Sixty-two infants met inclusion criteria. There was high interrater reliability in determining whether hospitalizations were prolonged (kappa = 0.75). In 16 (26%) of 62 patients (95% confidence interval, 15%-37%), the hospitalization was prolonged because of oxygenation concerns. Length of stay was prolonged an average of 1.6 days (range, 1.1-2.0 days) per hospitalization for these 16 patients, or 0.4 day (range, 0.2-0.6 day) per hospitalization for all 62 patients.

CONCLUSIONS

Hospitalizations of some infants with bronchiolitis are prolonged by a perceived need for supplemental oxygen therapy based on pulse oximetry readings. Further investigation into outcomes of different levels and durations of oxygen desaturation is needed and would have the potential to reduce practice variability and shorten the length of stay.