Congenital abnormalities among children with cerebral palsy: More evidence for prenatal antecedents.

OBJECTIVES: To investigate the association between cerebral palsy (CP) and congenital abnormalities among children with very low, low, and normal birth weight. STUDY DESIGN: A population-based, case-control study among the cohort of 155,636 live births delivered between 1983 and 1985 in 4 California counties. Children with moderate or severe congenital CP (n = 192) diagnosed by age 3 were identified from 2 California State service agencies, and 551 control children were randomly sampled from birth certificate files. Information on congenital abnormalities diagnosed by the age of 1 year was obtained from the California Birth Defects Monitoring Program registry. Odds ratios (OR) and 95% CIs were calculated to estimate risk for CP associated with congenital abnormalities. RESULTS: Among singletons, congenital abnormalities were present in 33 (19.2%) children with CP and 21 (4.3%) control children (OR = 5.2, 95% CI 2.8-9.7). For each birth weight group, the percent of children with congenital abnormalities among children with CP exceeded that among control children. Structural abnormalities of the central nervous system were more common among children with CP (OR = 16.2, 95% CI 5.8-49.3) than control children. In contrast, the percent of children with non-central nervous system abnormalities only was similar between case patients and control subjects. CONCLUSION: These findings provide further evidence that factors operating in the prenatal period contribute significantly to the etiology of CP.

Interferons and cerebral palsy.

OBJECTIVE: To explore the association of neonatal interferons (IFNs) with spastic cerebral palsy (CP) and with other measured substances. STUDY DESIGN: Assays of archived neonatal blood of 31 predominantly term children with CP and 65 children in a control group were obtained by recycling immunoaffinity chromatography with laser-enhanced fluorescence and chemiluminescence detection. RESULTS: Fourteen of 31 children with spastic CP had concentrations of IFNs-alpha, beta, and gamma exceeding any control. Levels of interleukins-1, 6, 8, tumor necrosis factor-alpha, chemokines, colony stimulating factors, transforming growth factor-beta, complement components and regulators, certain neuropeptides, and thyroid hormones also differed from control levels in these 14 children. The 17 children with CP whose IFN concentrations were within the control range had levels of inflammatory cytokines higher than but near to control values; 13 of these 17 had values for coagulation factors that exceeded control values. Seven of 9 children with spastic diplegia had high IFNs, and 8 of 10 hemiplegic children had normal IFNs. CONCLUSION: Neonatal IFNs exceeding control concentrations were associated with other biochemical and clinical indicators of inflammation and with spastic diplegia. In these children with CP, IFNs within the control range were associated with concentrations of other inflammatory markers that were near to control values and with spastic hemiplegia.

Prenatal and perinatal factors and cerebral palsy in very low birth weight infants.

OBJECTIVE: To identify prenatal and perinatal characteristics associated with cerebral palsy (CP) in infants born weighing < 1500 gm (very low birth weight, VLBW). DESIGN: All 42 VLBW singleton infants with CP born in the period from 1983 to 1985 in a defined population were compared with 75 randomly selected VLBW control infants. RESULTS: Birth in a level I facility was associated with increased risk of CP (odds ratio (OR) 6.3, 95% confidence interval (CI) 1.8, 19), as was birth within 3 hours of the mother's first admission for delivery (OR 3.2, CI 1.4, 7.4). Delivery occurred within 3 hours of admission to a level I facilty in 24% of VLBW children with CP and no control children (OR (0.5 added to each cell of 2 x 2 table) 49, CI 3.1, 204). Chorionitis was associated with increased risk in children born more than 5 hours after admission (OR 4.3, CI 1.1, 13). Chorionitis followed by neonatal seizures occurred in 14% of VLBW children with CP (in 25% with spastic diplegia) and in no control child (OR (0.5 added to each cell of 2 x 2 table) 26, CI 1.6, 116). Preeclampsia was associated with decreased risk (OR 0.08, CI 0.02, 0.67), as was use of magnesium sulfate (OR 0.14, CI 0.05, 0.51) administered for preeclampsia or preterm labor. Other risk factors for CP included gravidity greater than one (OR 3.9, CI 1.2, 11), short interbirth interval (OR 4.1, CI 1.3, 12), and vaginal bleeding on the day of admission (OR 2.9, CI 1.2, 7.4). CONCLUSIONS: In this population-based study, almost one fourth of the CP in VLBW children occurred in infants delivered in level I facilities soon after their mothers' admissions. Another 14% was in children who had neonatal seizures after birth to women with chorionitis. No control subject experienced either of these sequences.

Cerebral palsy in four northern California counties, births 1983 through 1985.

To examine the impact of demographic shifts and changes in perinatal medicine on the distribution of cerebral palsy (CP), we investigated characteristics of affected children in a large, recent population-based American cohort study. Children with moderate or severe congenital CP born in four northern California counties in 1983 through 1985 and surviving to age 3 years were identified through records of state service agencies and clinical examination or record review by a single physician. We compared information from birth certificates for 192 children with CP and 155,636 survivors without CP born in those counties in the same period. Children with birth weights < 2500 gm contributed 47.4% of the CP in this population; those < 1000 gm, who were 0.20% of survivors, contributed 7.8%. Children with birth weights of 4000 to 4500 gm were at lowest risk. Among singletons, prevalence of CP was lowest (0.92/1000) in infants born to women aged 25 to 34 years, and was significantly higher in children whose mothers were 40 years or older (3.3/1000), especially if they were high in parity (6.9/1000). Children of teenaged mothers or fathers were at somewhat increased risk of CP. Early gestational age at birth was also an important independent risk factor. Prevalence of CP was slightly higher in black children, apparently related to a greater tendency to be low in birth weight. The time during pregnancy when prenatal care began was similar for children with CP and for the general population. For the 95% of children born weighing > or = 2500 gm, birth in a hospital lacking a special care nursery was not associated with increased risk of CP. Almost 8% of CP occurred in children born weighing < 1000 gm, a group that produced few survivors in the past; 28.1% occurred in children born weighing < 1500 gm. Neither early initiation of prenatal care nor, for that large majority of neonates weighing > 1500 gm, delivery at a hospital with specialized facilities was associated with a lower risk of CP.

Sudden infant death syndrome among Asians in California.

We analyzed California linked birth and infant death records for 1978 to 1985 to determine the ethnic-specific incidence of sudden infant death syndrome in five Asian-American subgroups, and to assess the association of sudden infant death syndrome with cultural assimilation. The overall incidence of sudden infant death syndrome for these groups was 1.1/1000 live births (194 cases). The ethnic-specific incidence was statistically associated with the immigration status of each ethnic group, as measured by the proportion of all live births for which the mother was born in the United States, with a higher incidence for groups that have been in the United States for the longest period. A logistic model was used to examine simultaneously the association of sudden infant death syndrome with maternal ethnicity, ethnic homogeneity or heterogeneity of the parents, and maternal birthplace (United States, or elsewhere). The logistic analysis did not yield statistically significant evidence to support cultural assimilation as a factor in the incidence of sudden infant death syndrome for these groups. This finding may be due to small sample size and inadequate indicators of assimilation. It may also be that other factors relating to immigration and selective migration affect the incidence of sudden infant death syndrome among Asian-Americans.

Sudden infant death syndrome and birth weight.

We studied 2962 cases of sudden infant death syndrome (SIDS), derived from linked birth and death records, to specify further the descriptive epidemiologic data on recognized SIDS risk factors and to examine interrelationships among multiple risk factors and SIDS while controlling for the influence of birth weight (using logistic regression). The results generally confirmed those of other studies, with the exception of a higher incidence of SIDS among Chinese and Japanese babies and a lower incidence among Hispanic babies, all in comparison with white, non-Spanish (Anglo) infants. Median age at death was found to vary by birth weight, with very low birth weight babies being about 6 weeks older (postnatal age) than normal birth weight babies at time of death. The association of the risk factors with SIDS remained when birth weight data were statistically controlled; the association of these risk factors with SIDS cannot be explained by their relationship to birth weight. An interaction was found between race and maternal age and between multiparity and type of hospital of birth. There was no interaction between birth weight and the other risk factors.