The proportion of postmenopausal breast cancer cases in the Netherlands attributable to lifestyle-related risk factors.

We aimed to estimate the proportion of Dutch postmenopausal breast cancer cases in 2010 that is attributable to lifestyle-related risk factors. We calculated population attributable fractions (PAFs) of potentially modifiable risk factors for postmenopausal breast cancer in Dutch women aged >50 in 2010. First, age-specific PAFs were calculated for each risk factor, based on their relative risks for postmenopausal breast cancer (from meta-analyses) and age-specific prevalence in the population (from national surveys) around the year 2000, assuming a latency period of 10 years. To obtain the overall PAF, age-specific PAFs were summed in a weighted manner, using the age-specific breast cancer incidence rates (2010) as weights. 95 % confidence intervals for PAF estimates were derived by Monte Carlo simulations. Of Dutch women >40 years, in 2000, 51 % were overweight/obese, 55 % physically inactive (<5 days/week 30 min activity), 75 % regularly consumed alcohol, 42 % ever smoked cigarettes and 79 % had a low-fibre intake (<3.4 g/1000 kJ/day). These factors combined had a PAF of 25.7 % (95 % CI 24.2-27.2), corresponding to 2,665 Dutch postmenopausal breast cancer cases in 2010. PAFs were 8.8 % (95 % CI 6.3-11.3) for overweight/obesity, 6.6 % (95 % CI 5.2-8.0) for alcohol consumption, 5.5 % (95 % CI 4.0-7.0) for physical inactivity, 4.6 % (95 % CI 3.3-6.0) for smoking and 3.2 % (95 % CI 1.6-4.8) for low-fibre intake. Our findings imply that modifiable risk factors are jointly responsible for approximately one out of four Dutch postmenopausal breast cancer cases. This suggests that incidence rates can be lowered substantially by living a more healthy lifestyle.

Examination of long-lasting parental concern after false-positive results of neonatal hearing screening.

OBJECTIVE: To investigate whether false-positive outcomes on neonatal hearing screening cause long-lasting parental concerns. METHODS: A general population of parents whose children had participated in the universal neonatal hearing screening (UNHS) programme were examined. Parents filled out a questionnaire 6 months after UNHS. Outcomes were compared for all parents whose child tested positive or inconclusive in at least one of three tests but afterwards proved not to have hearing impairment (cases, n = 154) and a random sample of parents whose child passed the first test (controls, n = 288). Parental anxiety as measured with the State-Trait Anxiety Inventory (STAI), attitude towards the child (child health rating and experienced problems) and sensitivity to hearing problems were measured. RESULTS: Median STAI score was equal for cases and controls. Parental attitudes toward the child also did not differ. The difference in the proportion of parents who worried about their child's hearing was statistically significant between cases and controls (p = 0.001) and varied with the number of screens; 4% of controls were worried about the child's hearing, as compared to 10% of cases whose children were tested twice, and 15% of cases whose children were tested three times. CONCLUSIONS: False-positive UNHS test results do not cause long-term general parental anxiety. However, 6 months after screening, a considerable proportion of parents continued to experience hearing-specific worries regarding their child.

[Slight decrease in the prevalence of smoking around pregnancy]. / Licht dalende prevalentie van roken rondom de zwangerschap.

OBJECTIVE: To establish smoking prevalence of fertile-aged women; before and during pregnancy, and 6 months after delivery. DESIGN: Cross-sectional. METHOD: Yearly surveys by questionnaires handed out during 2001-2003 to mothers visiting a Well Baby Clinic with infants aged 0-6 months. RESULTS: Out ofa total of 14,540 questionnaires, 9133 (63%) were completed and returned. Before pregnancy 25% of all the women concerned smoked, 6% stopped 6 months before getting pregnant; this percentage rose between 2001 (5%) and 2003 (7%). During pregnancy, 14% of the women smoked. This percentage was significantly lower in 2002 and 2003 (13%) compared to 16% in 2001. 11% smoked while pregnant (average 5 cigarettes daily), and 3% stopped some time during pregnancy. Of the mothers who quitted smoking before or during pregnancy, two thirds did so permanently. Nevertheless 15% of all women smoked during the first half year after delivery. This percentage was lowest in 2003 (14%) and highest in 2001 (17%). 28% of all mothers with infants aged 0-6 months had partners who smoked (daily 10 cigarettes average), these women were more likely to start smoking again (RR: 2). CONCLUSION: Minor positive changes were observed within the study period. A smoking partner contributed to smoking relapse after delivery.

Neonatal screening for congenital hypothyroidism based on thyroxine, thyrotropin, and thyroxine-binding globulin measurement: potentials and pitfalls.

CONTEXT: The Dutch T(4)-TSH-TBG-based neonatal screening program detects patients with congenital hypothyroidism (CH) of thyroidal (CH-T) as well as central (CH-C) origin. The numbers and characteristics of true-positive and false-positive referrals will differ from other, predominantly TSH-based, screening methods. OBJECTIVE: The present study describes the characteristics of the referred neonates, both CH patients and false positives, and of the reported CH patients with a false-negative screening result born in the study period. DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURE: For each referred child born between April 1, 2002, and May 31, 2004, screening results and first venous sample results were recorded and classified as transient or permanent CH-T or CH-C or as no CH. RESULTS: In the study period, 430,764 children were screened. Of the 772 children with abnormal screening results, 224 (29%) had CH; another 13 CH patients did not have abnormal screening results, giving an overall CH incidence of 1:1800. Incidences of permanent CH, permanent CH-T, permanent CH-C, and transient CH were 1:2200, 1:2500, 1:21,000, and 1:12,000, respectively. The most frequent explanations for the 548 false-positive referrals (71% of the referred cohort) were severe illness and TBG deficiency (occurring in 198 and 200 children, respectively). CONCLUSIONS: The Dutch incidence figures for CH belong to the highest worldwide, suggesting that the T(4)-TSH-TBG screening program is an efficient method to detect CH of variable etiology and severity. Still, a small percentage of children with CH escaped detection via this screening approach. Severe illness and TBG deficiency appear to be responsible for the majority of false-positive referrals.

Determinants of Dutch parents' decisions to vaccinate their child.

This study examines the factors that influence parents' decisions to have their children vaccinated under the Dutch National Immunisation Programme. A computer questionnaire was sent to 500 parents in 1999 (the response rate was 98.2%). The intention to vaccinate was most strongly determined by attitudes. The belief that vaccination is safe and the best way to protect children against infectious diseases positively influenced parents' attitudes. The idea that children receive too many vaccines simultaneously and that vaccination interferes with natural development had a negative effect on attitudes. Dutch parents believe that doctors only inform them about the benefits of vaccination and disregard possible drawbacks. Since attitudes did not appear to be the result of thorough deliberation, parents could easily be influenced by negative publicity about vaccination. Educational campaigns and practitioners' advice should provide complete information about all aspects of the question, enabling parents to make well-considered and therefore enduring decisions.

Sudden infant death syndrome in child care settings in the Netherlands.

BACKGROUND: In the Netherlands, there is a very low incidence of sudden infant death syndrome (SIDS) due to effective preventive campaigns. METHODS: During the period September 1996 to August 2002, nationwide 161 deaths from SIDS (about 85% of all cases of SIDS during that time) were investigated by the Cot Death Committee of the Dutch Paediatric Association. RESULTS AND DISCUSSION: Over 10% of cases of SIDS took place during some type of child care. From a national survey carried out in 2000/01 information was available on the child care attendance of 2000 Dutch infants aged 3-6 months. Based on the hours usually spent in child care by these infants, the number of similarly aged infants that died from SIDS while attending child care was 4.2 times higher than expected. Remarkably, the prevalence of known risk factors for SIDS, such as sleeping position and parental smoking, was favourable in the SIDS cases in child care settings. The adherence of child care facilities to the safe sleeping recommendations is high in the Netherlands, and no explanation as to why child care settings may be associated with an increased risk of SIDS is apparent. The possibility of other explanations, such as stress and change in routine care, is hypothesised.

Environmental exposure to polychlorinated biphenyls (PCBs) and dioxins. Consequences for longterm neurological and cognitive development of the child lactation.

UNLABELLED: Polychlorinated biphenyls (PCBs) and dioxins are environmental pollutants. Prenatally, as well as postnatally through breast feeding, large amounts are transferred from mother to the child. Formula is free of these substances. Considering their potential developmental neurotoxicity, we investigated long term effects of perinatal exposure to PCBs and dioxins on neurological and cognitive development. Given the evidence that PCBs exert oestrogenic effects, and oestrogens are known to suppress lactation, we investigated the effect of maternal PCB body load on lactation performances as well. METHODS: A group of 418 infants were followed from birth up to 6 years of age. Half of them were fully breast fed (BF) for at least 6 weeks. Prenatal PCB exposure was measured from cord and maternal blood. Postnatal exposure was reflected by PCB and dioxin levels in breast and formula milk and plasma PCB levels at 42 months of age. Both neurological and cognitive development were taken as outcome variable at 18, 42 months and at 6 years of age. At 18 and 42 months of age neurological condition was evaluated according to Hempel and at 6 years of age according to Touwen. Condition was evaluated in terms of optimality. Separately, the fluency of movements was scored. Cognitive abilities were measured at 18 months by the Bayley Scales of Infant Development, at 42 months of age by the Kaufman Assessment Battery for Children (K-ABC) and at 6 years of age by the McCarthy Scales. Daily breast milk volume and milk fat content in relation to PCB body load was evaluated in 102 mothers. Multivariate regression models were applied to analyse associations of measured exposure variables with independent variables adjusted for confounders. RESULTS: At 18 months of age cognitive development was not affected by either pre- or postnatal exposure to the measured PCBs and dioxins. However, neurological examination showed an adverse effect of prenatal exposure to the measured pollutants on neurological optimality score. At 42 months of age we found negative associations between prenatal PCB exposure on cognitive development. However no effect was demonstrated on postnatal exposure to the measured pollutants. Neurological development was not affected by either pre- or postnatal exposure to PCBs and dioxins. At 6 years of age the preliminary results revealed evidence that cognitive development is affected by prenatal exposure to these pollutants in children from young mothers. An adverse effect of prenatal exposure on neurological outcome was also demonstrated in the formula fed group but not in the breast fed group. Despite a higher PCB exposures from breast milk we found at 18 months, 42 months of age, and at 6 years of age a beneficial effect of breast feeding on the quality of movements, in terms of fluency, and on the cognitive development tests. Maternal PCB body load was inversely related to 24-h breast milk volume and milk fat content. CONCLUSION: These data give evidence that prenatal exposure to PCBs do have subtle negative effects on neurological and cognitive development of the child up to school-age. Human breast milk volume and fat content is adversely affected by the presently encountered PCB levels in W. Europe. Our studies showed evidence that breast feeding counteracts the adverse developmental effects of PCBs and dioxins.

Effects of environmental exposure to polychlorinated biphenyls and dioxins on cognitive abilities in Dutch children at 42 months of age.

OBJECTIVE: To study possible adverse effects of environmental exposure to polychlorinated biphenyls (PCB) and dioxins on cognitive functioning in young children. METHODS: In a follow-up of the Dutch PCB/Dioxin study, cognitive abilities were assessed with the Kaufman Assessment Battery for Children in 42-month-old children (n = 395). In a subgroup (n = 193) verbal comprehension was assessed with the Reynell Language Developmental Scales. Prenatal PCB exposure was estimated from the sum of PCBs 118, 138, 153, and 180 (SigmaPCB) in maternal plasma. Lactational exposure was assessed from breast milk PCB and dioxin concentrations, multiplied by the number of weeks of breast-feeding. Current PCB body burden was estimated from SigmaPCB in 42-month-old plasma samples. RESULTS: After adjustment was done for covariables, maternal SigmaPCB was associated with lower scores on the overall cognitive and sequential and simultaneous processing scales of the Kaufman Assessment Battery for Children (all P <.05). The highest exposed group (SigmaPCB >/= 3 microg/L) scored 4 points lower on all 3 scales of the K-ABC when compared with the lowest exposed group (SigmaPCB < 1.5 microg/L). Both lactational exposure and current exposure to PCBs and dioxins were not related to 42-month cognitive performance. CONCLUSIONS: In utero exposure to "background" PCB concentrations is associated with poorer cognitive functioning in preschool children. Children of mothers at the upper end of exposure are especially at risk. Therefore maternal PCB body burden should be reduced, and breast-feeding should not be discouraged.

Polychlorinated biphenyls in adipose tissue, liver, and brain from nine stillborns of varying gestational ages.

We analyzed polychlorinated biphenyls (PCBs) in s.c. adipose tissue, liver, and brain of nine fetuses who died in utero. Their median (range) gestational ages and birth weights were 34 (17-40) wk and 2050 (162-3225) g. Three fetuses were small for gestational age. The levels of PCB congener nos. 118, 138, 153, and 180, and the sum of these (sigmaPCB), were calculated in terms of tissue total fat content (ng/g fat). The median (range) sigmaPCB (in ng/g fat) amounted to adipose tissue 235 (97-768), liver 198 (67-362), and brain 50 (22-122). Median (range) sigmaPCB levels in liver and brain were 0.8 (0.4-0.9) and 0.2 (0.1-0.3) times, respectively, as high as the sigmaPCB levels in adipose tissue. There were strong relations between sigmaPCB in adipose tissue and sigmaPCB in liver (r=0.98; p < 0.01), and between sigmaPCB in adipose tissue and sigmaPCB in brain (r=0.91; p < 0.01). Adipose tissue, liver, and brain did not show differences in the distribution of congeners 118, 138, 153, and 180, and there was no statistically significant association between tissue PCB levels and gestational age (r varied between 0.22 and 0.47). Median sigmaPCB levels in fetal adipose tissue proved to be comparable with our previously established sigmaPCB levels in mature breast milk of 93 Dutch women (median 414; range 158-969 ng/g of fat). The PCB congeneric distribution of fetal adipose tissue was not different from that of human milk. We conclude that maternal PCBs have a tendency to accumulate notably in fetal tissues with high triglyceride contents. They are easily transferred across the placenta and seem to become equilibrated among the apolar parts of maternal and fetal lipids.

Determinants of polychlorinated biphenyl levels in plasma from 42-month-old children.

We report on the PCB levels in plasma from 42-month-old children and the factors that determine these levels. We measured the levels of the PCB congeners 118 (2,4,5-3'4' pentachlorobiphenyl (CB)), 138 (2, 3,4-2'4'5'hexaCB), 153 (2,4,5-2'4'5'hexaCB), and 180 (2,3,4, 5-2'4'5'heptaCB) in cord plasma, breast milk, and plasma from 42-month-old children (n = 126) living in the Groningen area, The Netherlands. The sum of the levels of these four congeners was calculated for cord plasma (SigmaPCBcord), breast milk (SigmaPCBmilk), and 42-month plasma (SigmaPCB42mo). SigmaPCBcord was used as a measure of prenatal exposure. Postnatal exposure was assessed in terms of the SigmaPCBmilk and the duration of lactation. In addition, maternal factors including age, body weight and height, parity, and formal education were recorded. In 42-month-old children who have been fully breast-fed for at least six weeks as babies, the median SigmaPCB42mo was 4.5 times as high as that in formula-fed children (0.81 microg/L vs. 0.18 microg/L). The PCB levels in cord blood and human milk and the duration of breast-feeding predict the plasma PCB level at 42 months. Each additional week of full breast-feeding is estimated to result in an increase of 0.3% of the milk PCB level. We concluded that lactation is a major source for the child's PCB body burden at 42 months.

Neurological condition in 42-month-old children in relation to pre- and postnatal exposure to polychlorinated biphenyls and dioxins.

Adverse neurological effects of exposure to PCBs have been found up to 18 months of age. Now we report on the effect of pre- and postnatal exposure to PCBs and dioxins on the neurological condition at 42 months of age. For this purpose, PCB levels were determined in cord and maternal plasma, and used as a measure of prenatal exposure. Breast milk was analyzed for PCBs and dioxins. In addition, PCBs were determined in plasma sampled from the child at 42 months of age. We evaluated the neurological condition of 394 children using the Touwen/Hempel method. After adjustment for covariates, neither prenatal PCB exposure nor postnatal exposure to PCBs and dioxins was found to be related to the neurological condition at 42 months of age.

Breastfeeding and neurological outcome at 42 months.

This study investigated the effect of early feeding mode on the neurological condition at 42 months. For this purpose, healthy pregnant women were recruited in Groningen and Rotterdam, The Netherlands. Children were healthy and born at term. At 42 months, the children were neurologically examined by means of the Touwen/Hempel technique. In addition to the clinical diagnosis, the neurological findings were interpreted in terms of optimality. Special attention was paid to the quality of movements in terms of fluency. In total, 200 (51%) exclusively breastfed(for > or = 6 weeks) and 194 (49%) formula-fed children were studied. Twelve (3%) 42-month-old children were considered to be neurologically mildly abnormal and 1 child was diagnosed as abnormal. No effect of the type of feeding was found on the clinical diagnosis or the neurological optimality. After adjustments for study centre and social, obstetric, perinatal and neonatal neurological differences, a beneficial effect of breastfeeding on the fluency of movements was found (odds ratio for non-optimal fluency 0.56; 95% confidence interval 0.37-0.85). The prolongation of full breastfeeding beyond 6 weeks did not influence the quality of movements. In conclusion, among Dutch preschool children, there was a small advantageous effect of full breastfeeding during the first 6 weeks of life on the fluency of movements.

Triglycerides, fatty acids, sterols, mono- and disaccharides and sugar alcohols in human milk and current types of infant formula milk.

OBJECTIVE: To investigate differences in the fatty acid composition, sterols, minor carbohydrates and sugar alcohols between human and formula milk. DESIGN: We analyzed the concentrations of triglycerides, sterols, di- and monosaccharides and sugar alcohols, as well as the fatty acid composition of 10 currently available types of formula milk for term babies. Results were compared with mature human milk from 99 exclusively breast-feeding Dutch women, who collected 24-hour samples in the second week (n = 99), sixth week (n = 99) and 3 months (n = 25) after delivery. Infant formula milk data were considered different if they fell outside the mean +/- 2s.d. range of corresponding human milk data. RESULTS: The triglyceride concentrations in human milk were lower than those of the formula milk, possibly due to an incomplete collection of fat-rich hindmilk. Formula milks tended towards a higher proportion of medium chain fatty acids and lower proportions of longer-chain polyunsaturated fatty acids. Formulas had cholesterol concentrations 3-35 times lower, and much higher phytosterol concentrations, compared with the human milk. In the formula milk types the glucose, sorbitol and myoinositol concentrations were generally lower, whereas the fucose and erythreitol concentrations were in the lower mean +/- 2s.d. human milk range. The galactose concentrations in the formulas were generally higher. CONCLUSIONS: Formula milk and human milk differ considerably in fatty acid composition and concentrations of cholesterol, phytosterols, monosaccharides and sugar alcohols. The biological consequences of these differences in composition are uncertain.

Lipids in infant nutrition and their impact on later development.

Numerous studies on infant nutrition show that breast-feeding has a beneficial effect on growth, morbidity, and neurological and cognitive functioning later in life. Moreover, there are indications that a relationship exists between the diet consumed during early childhood and morbidity in adulthood, such as atherosclerosis and insulin-dependent diabetes mellitus. The mechanism causing this advantageous effect of breast-feeding might be found in the fatty acid composition of human milk. The fatty acid content of formula milk is associated with biochemical parameters, cognitive development, and growth. Further research concentrating on randomized trials of 'fatty acid-enriched' formula milks is needed for the sake of children of mothers who opt for bottle-feeding.

Neurological condition in 18-month-old children perinatally exposed to polychlorinated biphenyls and dioxins.

The neurological optimality of 418 Dutch children was evaluated at the age of 18 months, in order to determine whether prenatal and breast milk mediated exposure to polychlorinated biphenyls (PCBs) and dioxins affected neurological development. Half of the infants were breast-fed, the other half were formula-fed. PCB concentrations in cord and maternal plasma were used as a measure of prenatal exposure to PCBs. To measure postnatal exposure, PCB and dioxin congeners were determined in human milk and in formula milk. After adjusting for covariates, transplacental PCB exposure was negatively related to the neurological condition at 18 months. Although greater amounts of PCBs and dioxins are transferred via nursing than via placental passage, an effect of lactational exposure to PCBs and dioxins could not be detected. We even found a beneficial effect of breast-feeding on the fluency of movements. We conclude that transplacental PCB passage has a small negative effect on the neurological condition in 18-month-old toddlers.

Neurological differences between 9-year-old children fed breast-milk or formula-milk as babies.

The presence of minor neurological dysfunction is associated with behavioural and cognitive development at school age. We have previously shown a relation between minor neurological dysfunction and perinatal disorders, especially abnormal neonatal neurological condition. We have now investigated the relation between breastfeeding and long-term neurological development. We studied 135 breastfed (for > or = 3 weeks) and 391 formula-fed children, born at term in the University Hospital Groningen between 1975 and 1979. A standard neonatal neurological examination was used to classify the infants as normal (247), slightly abnormal (213), or frankly abnormal (66). At 9 years of age the children were reexamined. In 1993 their mothers were asked to complete a questionnaire about how the children were fed as infants. After adjustment for obstetric, perinatal, neonatal neurological, and social differences, a small advantageous effect of breastfeeding on neurological status at 9 years of age was found (odds ratio for neurological non-normality 0.54 [95% CI 0.30-0.97]). Although a retrospective design cannot lead to definite conclusions, our data suggest a beneficial effect of breast-feeding on postnatal neurological development. Longer-chain polyunsaturated fatty acids, which are present in breast-milk but not in most formula-milks, may have a role since they are vital for brain development.

Perinatal and neonatal care at the Port-of-Spain General Hospital, Trinidad: an analysis of mortality - abstract

In this retrospective study the following information was recorded for all 1,296 infants born in 1990 and admitted to the neonatal ward, General Hospital, Port-of-Spain: date of birth, gestational age, birthweight, Apgar scores after one and five minutes, type of delivery, foetal presentation, mother's address and data concerning death. The annual perinatal mortality rate was 25.2 per 1,000 live births. The neonatal mortality rate (NMR) equaled 12.8 per 1,000 live births and the still birth rate was 15.0 per 1,000 births. The NMR for the month of August was remarkably high. During the past ten years, the NMR showed a sharp decline since 1982. From a regression analysis, birthweight (R2 = .27), Apgar score after five minutes (R2 = .26) and gestational age (R2 = .22) emerged as predictors of neonatal mortality. Birthweight-specific NMRs in infants born in a regional hospital were equal to or higher than our monthly, yearly and interhospital variations in mortality rates, although the effects of differences in the study populations cannot be completely excluded (AU)