Maternal vitamin D status in pregnancy and molar incisor hypomineralisation and hypomineralised second primary molars in the offspring at 7-9 years of age: a longitudinal study.

PURPOSE: The study aimed to investigate associations between maternal vitamin D status during pregnancy and molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) among children. METHODS: The study had a longitudinal design using prospectively collected data from 176 mother and child pairs. Mothers were initially recruited in a randomised controlled trial to assess a pregnancy exercise programme. Along with the 7-year follow-up, we invited the children to a dental examination. The exposure variable was maternal serum 25-hydroxyvitamin D in gestational weeks 18-22 and 32-36, categorised as insufficient (< 50 nmol/l) and sufficient (≥ 50 nmol/l). Negative binomial hurdle models were used to analyse potential associations between the exposure variables and MIH or HSPM. The models were adjusted for potential confounders. RESULTS: Among the children (7-9 years old), 32% and 22% had at least one tooth with MIH or HSPM, respectively. A significant association was found between insufficient maternal vitamin D measured in gestational weeks 18-22 and the number of affected teeth among those with MIH at 7-9 years (adjusted RR = 1.82, 95% CI 1.13-2.93). CONCLUSION: Considering any limitations of the present study, it has been shown that insufficient maternal serum vitamin D at mid-pregnancy was associated with a higher number of affected teeth among the offspring with MIH at 7-9 years of age. Further prospective studies are needed to investigate whether this finding is replicable and to clarify the role of maternal vitamin D status during pregnancy and MIH, as well as HSPM, in children.

Specific language impairment is associated with maternal and family factors.

BACKGROUND: This study aimed to identify risk factors associated with specific language impairment (SLI). METHODS: In a nested case-control design, 253 children attending special needs schools for severe speech and language difficulties in the Netherlands were matched for sex and date of birth with 253 children attending mainstream education. Data on perinatal, maternal and family issues were retrieved from well-child care files registered shortly after birth. RESULTS: Children with SLI had younger mothers than children in the control group (mean 30 years 9 months vs. mean 31 years 9 months) (P = 0.02). Children with SLI were less frequently breastfed directly after birth (55% vs. 71%) (P = 0.0007) and were less frequently firstborns (33.3% vs. 46.2%) (P = 0.002). No statistically significant differences were found for any of the other risk factors. CONCLUSIONS: A relationship was found between SLI and maternal age, being breastfed and place in the birth order. Perinatal risk factors do not seem to be strongly associated with SLI.

[Trends in DMF in children and adolescents from 1990 to 2009. Research in a changing context]. / Trends in cariësprevalentie bij kinderen en jongeren van 1990-2009. Een onderzoek in een veranderende context.

Since 1987, research has very frequently been carried out in the Netherlands on the oral health of children and adolescents, so-called 'TJZ research'. For an analysis of the trends in caries experience DMF in children and adolescents in the Netherlands, the results of the TJZ research from 1990, 1996, 2005 and 2011 were used. The changing social context and the fact that the age groups studied were different in the different years of survey were taken into account. The TJZ surveys were conducted among 8/9, 14/15 and 20/21-year-olds living in Alphen aan den Rijn, Gouda, Breda and's-Hertogenbosch and consisted of a questionnaire and a clinical oral examination. The results revealed that from 1990 to 2009, depending on age, either a decrease or no significant changes were seen in DMF. However, there is still room for further improvement in oral health in children and adolescents. It is up to the public debate to determine what extent of caries experience is acceptable from a public health perspective.

Trends in oral health in young people in the Netherlands over the past 20 years: a study in a changing context.

OBJECTIVES: From 1 January 2006, the distinction between the health insurance fund and private insurance was abolished and a basic insurance package was agreed for everyone in the Netherlands. Dental treatment for young people below the age of 18 is reimbursed under the terms of this basic package. Dental treatment for adults is not covered in this basic insurance package. Basic principles for nonreimbursing dental care for adults were that any health and financial risks for individual citizens in the future should be acceptable for them with the corollary that the oral health of young adults when they make the switch - from collectively financed care to care to be paid for individually - should be at such a level that the needed oral health care is affordable. To meet this requirement, it is important to have knowledge of the prevalence of oral diseases and trends in oral health in young people from a public health perspective. The aim of this article is to describe trends in caries experience in young people in the Netherlands from 1990 to 2009, taking into account the challenge in methodology concerning this changing social context. METHODS: To describe caries experience in young people, a repeated cross-sectional study design was used. The study consisted of a clinical oral examination and a questionnaire survey. Data were sampled from 8, 14 and 20-year-olds in 1990 and 1996, and 9, 15 and 21-year-olds in 2003 and 2009, living in Alphen a/d Rijn, Gouda, Breda and 's-Hertogenbosch. The DMF index was used for describing caries experience. The trends were studied separately in high and low socioeconomic status (SES) groups. SES was operationalized as the dichotomous variable of educational level of the mother or the adolescent. Multiple imputation was applied to predict the DMFS for missing ages for certain years, which made it possible to test the trends. Linear and logistic regression analyses were used to study the trends through the years. RESULTS: This study showed, according to different age- and SES groups, either declines or no statistically significant changes in caries experience over the last two decades. CONCLUSIONS: No deterioration was shown. However, there is still room for further improvement in oral health in children. Dental professionals and politicians should develop a vision on to what extent caries experience is acceptable in a public health perspective in young people.

Ten-year quality assurance of the nationwide hearing screening programme in Dutch neonatal intensive care units.

AIM: To evaluate 10-year quality assurance of newborn hearing screening (NHS) in Dutch neonatal intensive care units (NICU). METHODS: Results of the two-stage automated auditory brainstem response (AABR) screening and diagnostic examination in NICU graduates were centrally registered between October 1998 and December 2008. This registration facilitates screening, tracking and follow-up after abnormal screening results. Outcome measures are referral rates, prevalence rate of hearing loss and (trends of) coverage rates and timeliness of follow-up. RESULTS: Thirty-two thousand one hundred and two infants have been screened. Referral rates were 9.2% at the first and 26.3% at the second stage. Hearing loss was diagnosed in 728 infants (2.2%). Coverage rates were 98.7% at the first, 92.1% at the second stage, 92.3% for the diagnostic examination and 97.9% for the complete programme. After correction for gestational age, 95.8% of the infants had their first AABR<1 month, 81.8% of the referred infants had their second AABR<6 weeks and 67.1% were diagnosed<3 months. There was a positive trend in referred infants that had their second AABR<6 weeks (p=0.004) as well as in infants diagnosed<3 months (p<0.001). CONCLUSION: The NHS in Dutch NICUs is effective. Timely identification of hearing loss is improving over time.

Risk indicators for hearing loss in infants treated in different neonatal intensive care units.

AIM: To assess which infants' characteristics and specialized procedures are risk indicators for unilateral or bilateral hearing loss (HL) and to evaluate whether these risk indicators are associated with variation in prevalence of HL between Neonatal Intensive Care Units (NICUs). METHODS: For 2002-2005, data from the NICU hearing screening database in the Netherlands were matched with the national neonatology database in which all NICU infants with their patient characteristics and specialized procedures are registered. Multivariate logistic regression analyses were performed to assess risk indicators for HL and to explain differences in prevalence rates between NICUs. RESULTS: A total of 10 830 infants were available for analyses. The prevalence of HL was 1.8% and ranged from 0.7 to 3.7% between NICUs. Infants' characteristics that significantly increased the risk of HL were the presence of craniofacial anomalies, chomosomal/syndromal anomalies, central nervous system conditions, circulatory system conditions and intra-uterine infections. The specialized procedures involving > or =12 days of intensive care and high frequency oxygenation ventilation were independent risk indicators for HL. Approximately 20% of the variance can be explained by the studied risk indicators. Differences in prevalence rates between NICUs were slightly reduced after adjustment for these risk indicators. NICUs with the highest prevalence rates of HL were situated in the largest cities in the Netherlands with a mixed population because of immigration. Therefore, ethnicity may be a risk indicator. CONCLUSIONS: Several independent risk indicators for HL were found, but they could not explain all differences in prevalence rates of HL between NICUs.

Trends in overweight and obesity prevalence in Dutch, Turkish, Moroccan and Surinamese South Asian children in the Netherlands.

OBJECTIVE: To determine trends in the prevalence of overweight and obesity in children in The Hague (the Netherlands) from 1999 through 2007. DESIGN: Population-based study of a series of cross-sectional assessments of height and weight from electronic health records. SETTING: Child Health Care (Municipal Health Service), The Hague. PARTICIPANTS: 50,961 children aged 3-16 years, with Dutch (59%), Turkish (17%), Moroccan (13%) or Surinamese South Asian (11%) ethnicity, representative of the four major ethnic groups in The Hague, with 85,234 weight and height measurements recorded in 1999-2007. MAIN OUTCOME MEASURES: (Trends in) the prevalence of overweight (excluding obesity) and obesity as defined by the International Obesity Taskforce cut-off points, using logistic regression with year as independent variable. RESULTS: From 1999 through 2007 there was a decrease in the prevalence of overweight in Dutch girls from 12.6% to 10.9% (OR 0.96; 95% CI 0.95 to 0.98) and an increase in Turkish boys from 14.6% to 21.4% (OR 1.08; 95% CI 1.04 to 1.11). Obesity prevalence rose significantly in Turkish boys from 7.9% to 13.1% (OR 1.04; 95% CI 1.01 to 1.06) and in Turkish girls from 8.0% to 10.7% (OR 1.04; 95% CI 1.01 to 1.08). Dutch boys, and Moroccan and Surinamese South Asian boys and girls showed no significant trends. CONCLUSIONS: The declining prevalence of overweight in Dutch girls may indicate reversal of previous trends in the Netherlands. However, in Turkish children overweight prevalence and obesity is high and increasing. Further public health action is necessary, especially for Turkish children.

Developing evidence-based guidelines for referral for short stature.

OBJECTIVE: To establish evidence-based guidelines for growth monitoring on a population basis. STUDY DESIGN: Several auxological referral criteria were formulated and applied to longitudinal growth data from four different patient groups, as well as three samples from the general population. RESULTS: Almost 30% of pathology can be detected by height standard deviation score (HSDS) below -3 or at least two observations of HSDS below -2.5 at a low false-positive rate (<1%) in 0-3-year-old infants. For 3-10-year olds, a rule concerning distance to target height of >2 SD in combination with HSDS <-2.0 has the best predictive value. In combination with a rule on severe short stature (<-2.5 SDS) and a minor contribution from a rule on "height deflection", 85.7% of children with Turner syndrome and 76.5% of children who are short because of various disorders are detected at a false-positive rate of 1.5-2%. CONCLUSIONS: The proposed guidelines for growth monitoring show high sensitivity at an acceptably low false-positive rate in 3-10-year-old children. Distance to target height is the most important criterion. Below the age of 3 years, the sensitivity is considerably lower. The resulting algorithm appears to be suitable for industrialised countries, but requires further testing in other populations.

[Weight loss, serum sodium concentration and residual symptoms in patients with hypernatremic dehydration caused by insufficient breastfeeding]. / Gewichtsverlies, serumnatriumconcentratie en restverschijnselen bij patiëntjes met hypertone dehydratie door onvoldoende borstvoeding.

OBJECTIVE: To determine the relationship between serum sodium concentration and weight loss as well as residual symptoms in newborns with hypernatremic dehydration caused by insufficient breastfeeding; and to determine the sensitivity of the following rule of thumb 'if weight loss is less than 10%, the baby does not have hypernatremic dehydration caused by insufficient breastfeeding'. DESIGN: Systematic literature search. METHOD: Medline was searched using the terms 'dehydration AND breastfeeding' for case reports on patients with 'hypernatremic dehydration caused by insufficient breastfeeding'. Reference lists from the articles retrieved were also searched. Articles published in 1970-2004 in Dutch, English, French, and German were included. All cases that the author diagnosed as 'hypernatremic dehydration caused by insufficient breastfeeding' were included. RESULTS: A total of 47 articles were found, containing 128 relevant cases. Of these, 9 had less than 10% weight loss. Therefore, the sensitivity of the 10% rule was 93%. We found a linear relationship between the degree of weight loss and serum sodium concentration (Pearson's correlation coefficient = 0.71; p < 0.001). For every 10% increase in weight loss, the serum sodium concentration increased by 16 mmol/l (95% CI: 13-19). As the serum sodium concentration increased, the prevalence of residual symptoms increased. No residual symptoms were reported in patients with less than 10% weight loss. CONCLUSION: A relatively strong linear relationship was found between weight loss and serum sodium concentration. If the weight loss was more than 10%, the serum sodium concentration was beyond the range of normal values. The rule of thumb had a high sensitivity; however, the specificity should be determined before the rule of thumb is implemented.

Individual growth curve models for assessing evidence-based referral criteria in growth monitoring.

The goal of this study is to assess whether a growth curve model approach will lead to a more precise detection of Turner sydnrome (TS) than conventional referral criteria for growth monitoring. The Jenss-Bayley growth curve model was used to describe the process of growth over time. A new screening rule is defined on the parameters of this growth curve model, parental height and gestational age. The rule is applied to longitudinal growth data of a group of children with TS (n=777) and a reference (n=487) group. The outcome measures are sensitivity, specificity and median referral age. Growth curve parameters for TS children were different from reference children and can therefore be used for screening. The Jenss-Bayley growth model, which uses all longitudinal measurements from birth to a maximum age of 5 years with at least one measurement after the age of 2, together with parental height and gestational age can achieve a sensitivity of 85.2 per cent with a specificity of 99.5 per cent and a median referral age of 4.2 (the last measurement between the age of 2 and 5 of each child is considered to be the moment of referral). Sensitivity increases by 2 percentage points when decreasing the specificity to 99 per cent. The Jenss-Bayley growth model from birth to a maximum age of 8 years with at least one measurement after the age of 2, together with parental height results in a sensitivity of 89.0 per cent with a specificity of 99.5 per cent and a median referral age of 6.1. For a specificity of 98 per cent, we obtain a sensitivity of 92.3 per cent. In comparison to conventional rules applied to the same data, sensitivity is about 11-30 percentage points higher at the same level of specificity for the Jenss-Bayley growth rule. We conclude that from the age of 4, growth curve models can improve the screening on TS to conventional screening rules.

[Growth charts for height, weight and body-mass index of twins during infancy]. / Groeidiagrammen voor lengte, gewicht en 'body mass index' van tweelingen in de peutertijd.

OBJECTIVE: To determine the magnitude of the growth retardation in Dutch monozygotic and dizygotic twins during infancy in comparison with the Dutch reference growth charts for general population infants from 1997 and to construct reference growth charts for twins. DESIGN: Descriptive. METHOD: The growth of twins was studied using longitudinal data on over 4000 Dutch twin pairs from birth until 2.5 years of age. The LMS method was used to obtain growth charts for height, weight and body-mass index (BMI) for twin pairs during infancy. Centiles were estimated by the Box-Cox power curve (L), the median curve (M) and the coefficient of variation curve (S). RESULTS: From birth until the age of half a year, the average height and weight of twin pairs were at about the 10th percentile of the Dutch reference population. One year later this difference had decreased to about the 25th percentile, and when the twin pairs were between 1.5 and 2.5 years of age the difference was further decreased to the 35th percentile. The BMI deviated less from that of the reference population: during the first half a year the BMI of twin pairs was at about the 25th percentile. Subsequently, the BMI improved, but remained slightly below the median of the reference population at the age of about two years. Approximately half (50% for height, 58% for weight) of the growth retardation from birth until 1.5 years was attributable to gestational age. Between 1.5 years and 2.5 years of age, this difference was reduced to one third: 33% for both height and weight. Thus, a substantial part of the growth difference could not be explained by gestational age. CONCLUSION: Correcting for gestational age alone is not sufficient to make possible a comparison of the growth of twin pairs with the growth of general population infants. The development of twins can, however, be followed by means of the reference growth charts designed by the authors.

Towards evidence based referral criteria for growth monitoring.

AIMS: To evaluate the performance of growth monitoring in detecting diseases. Turner's syndrome (TS) is taken as the target disease. METHODS: Case-control simulation study. Three archetypal screening rules are applied to longitudinal growth data comparing a group with TS versus a reference group from birth to the age of 10 years. Main outcome measures were sensitivity, specificity, and median referral age. RESULTS: Clear differences in performance of the rules were found. The best rule takes parental height into account. Combining rules could improve diagnostic accuracy. CONCLUSION: Growth monitoring is useful to screen for TS. A combined rule that takes absolute height SDS, parental height, and deflection in height velocity into account is the best way to do this. Similar research is needed for other diseases, populations, and ages, and the results should be synthesised into evidence based referral criteria.