Screening of hydrocephalus in infants using either WHO or population-based head circumference reference charts.

AIM: The aim was to compare the performances of the World Health Organization (WHO) and population-based (PB) references in the screening for hydrocephalus in infants aged <2 years. METHODS: We collected 341 longitudinal head circumference (HC) measurements of hydrocephalic infants and 120 181 measurements of 15 145 healthy infants from primary care. The measurements were converted into z-scores, and a new screening parameter, change in HC standard deviation score (SDS) over time (ΔHC SDS), was calculated. Comparisons were made using receiver operating characteristics analysis and linear mixed models. RESULTS: The mean HC SDSWHO was 3.5 and the mean HC SDSPB was 2.9 in the hydrocephalic infants, and in healthy children, those numbers were 1.0 SDSWHO and 0 SDSPB , respectively. The best screening accuracy was obtained with the PB reference in combination with the ΔHC SDS parameter (AUC 0.89). The accuracy of the WHO standard could be improved to a similar level by customising the screening cut-offs of HC SDS according to the population and combining screening parameters. CONCLUSIONS: Auxology alone was not sufficient for the screening of hydrocephalus. The WHO standard should be validated in the population, and population-specific cut-offs for normality defined before its introduction.

Genetics of head circumference in infancy: a longitudinal study of Japanese twins.

OBJECTIVES: Previous studies have shown strong genetic influence to head circumference (HC), but still little is known on the development of genetic etiology of HC in infancy, especially in non-Caucasian populations. Thus, we decided to analyze the genetics of HC growth in Japanese infants. METHODS: Longitudinal measures of HC were available from birth to 13 months of age in 206 monozygotic and 156 dizygotic complete twin pairs. Genetic modeling for twin data was used. RESULTS: We found only little evidence for sex-specific differences in the genetics of HC and thus analyzed boys and girls together. After 5 months of age the heritability of HC was high, but before that age also a substantial common environmental component was present. Not only strong genetic persistence for HC was found but also a new genetic variation emerged. New environmental variation shared by co-twins affecting HC was found until 3 months of age, and this effect was further transmitted until 1 year of age. CONCLUSIONS: HC and its growth are strongly genetically regulated. Largely, the same genetic factors affect the variation of HC at different ages, and new genetic variation emerged during the first year of life. Knowledge on the genetic component in the variation of HC may help to design tools for defining abnormal growth of HC in population-based screenings for related disorders.

Maternal Smoking During Pregnancy and Offspring Head Growth in Comparison to Height and Weight Growth Up to 6 Years of Age: A Longitudinal Study.

BACKGROUND: Maternal smoking during pregnancy causes fetal growth retardation. Thereafter, it has been associated with excessive childhood weight gain and decreased linear growth in the offspring. However, it is not known whether head circumference (HC), the surrogate of brain size in childhood, is altered after intrauterine tobacco exposure. We assessed the association of maternal smoking during pregnancy with offspring HC growth up to age 6 years in comparison with length/height growth and weight gain. METHODS: We combined data from Medical Birth Register and longitudinal growth data from primary care of 43,632 children (born 2004-2017). Linear mixed effects models were used for modeling, adjusting for potential perinatal and socioeconomic confounders. RESULTS: At birth, maternal smoking during pregnancy was associated with a mean deficit of 0.19 standard deviation score (SDS) (95% CI: -0.25, -0.12) in HC, -0.38 SDS (95% CI: -0.43, -0.32) in length, and -0.08 SDS (95% CI:-0.14, -0.02) in weight-for-length. HC in smokers' children failed to catch up to that of non-smokers' children. Height of smokers' infants reached that of non-smokers' infants by 12 months but declined thereafter. Weight-for-height of smokers' infants exceeded the level of non-smokers' infants at 3 months and remained significantly elevated thereafter. HC in the offspring of mothers who quit smoking in the first trimester was not deficient, but their weight-for-height was elevated. CONCLUSION: HC of smokers' children is still deficient at age 6 years. Since most of the head growth occurs during the first 2 years of life, the defect may be permanent. In smokers' children, weight gain was excessive up to 6 years and height was deficient at 6 years consistent with previous literature. Efforts should be made to encourage pregnant women to quit smoking in the beginning of the pregnancy.

Increased number of febrile seizures in children born very preterm: relation of neonatal, febrile and epileptic seizures and neurological dysfunction to seizure outcome at 16 years of age.

PURPOSE: In prematurely born population, a cascade of events from initial injury in the developing brain to morbidity may be followed. The aim of our study was to assess seizures in prematurely born children from birth up to 16 years and to evaluate the contribution of different seizures, and of neurological dysfunction to the seizure outcome. METHODS: Pre- and neonatal data and data from neurodevelopmental examination at 5 years of 60 prospectively followed children born at or before 32 weeks of gestation, and of 60 matched term controls from the 2 year birth cohort were available from earlier phases of the study. Later seizure data were obtained from questionnaires at 5, 9, and 16 years, and from hospital records and parent interviews. RESULTS: In the preterm group, 16 children (27%) exhibited neonatal seizures, 10 children (17%) had seizures during febrile illness and 5 children had epilepsy. Eight children had only febrile seizures, and 3 of these had both multiple simple and complex febrile seizures and neurodevelopmental dysfunction. None of the 8 children had experienced neonatal seizures, 6 had a positive family history of seizures, but none developed epilepsy. The children with epilepsy had CP and neurocognitive problems, and all but one had experienced neonatal seizures; two of them had also had fever-induced epileptic seizures. In controls 3 children (5%) had simple febrile seizures. CONCLUSION: Children born very preterm have increased rate of febrile seizures compared to the controls. However, no cascade from initial injury via febrile seizures to epilepsy could be shown during the follow-up of 16 years. Symptomatic epilepsy in prematurely born children is characterised by neonatal seizures, major neurological disabilities and early onset of epilepsy.

Elevated head circumference-to-height ratio is an early and frequent feature in children with neurofibromatosis type 1.

BACKGROUND/AIMS: Children with neurofibromatosis type 1 (NF1) tend to be macrocephalic and short. Our aim was to define the incidence and diagnostic accuracy of elevated head circumference-to-height ratio (HCHR) in children with NF1 and to assess if elevated HCHR would facilitate early diagnosis of NF1. METHODS: Retrospective analysis of growth and health data of 80 NF1 patients aged 0-7 years was performed. The incidence and diagnostic accuracy of elevated HCHR for NF1 was analyzed using receiver operating characteristic curves. RESULTS: The median age when the first elevated (≥2.0 SDS) HCHR value was detected was 0.3 years (range 0.0-5.3). At the median age of diagnosis (3.6 years), 53.8% of NF1 children exhibited elevated HCHR. The diagnostic accuracy of HCHR alone was 0.78 (95% CI 0.72-0.84), but in comparison with the seven National Institutes of Health diagnostic criteria for NF1, elevated HCHR was the second most prevalent feature. CONCLUSION: Elevated HCHR is an early and frequent feature in NF1 children. Taking HCHR into account would facilitate the early detection of NF1.

New Finnish reference for head circumference from birth to 7 years.

BACKGROUND AND OBJECTIVES: In the evaluation of the growth of head circumference (HC), charts depicting normal growth are of paramount importance. Current Finnish HC growth charts are based on data from only 130 children born 1953-1964. As a secular trend in HC growth has been reported, we updated the HC charts using a large sample of contemporary HC data. MATERIAL AND METHODS: Mixed cross-sectional HC data of 19,715 healthy subjects aged 0-7 years were collected from primary health care providers. References for HC for age and HC/height ratio for age were fitted using generalized additive models for location, scale, and shape (GAMLSS). RESULTS: Increased HC for age was seen particularly after 2 years of age in both genders compared to the 1953-1964 reference. The SD for HC was remarkably larger in the 1953-1964 reference. The proportion of 1986-2008 reference subjects exceeding the +2 SD limit of the 1953-1964 reference was much bigger than the proportion below -2 SD. CONCLUSIONS: Because of the secular change in HC growth, the HC reference has to be renewed periodically. The new Finnish reference for HC for age should be implemented for monitoring HC growth of children in Finland.