Long-chain polyunsaturated fatty acids and neurological developmental outcome at 18 months in healthy term infants.

AIM: Previously, we found a beneficial effect of 2 mo supplementation of infant formula with long-chain polyunsaturated fatty acids (LC-PUFA) on neurological condition at 3 mo in healthy term infants. The aim of the present follow-up study was to evaluate whether the effect on neurological condition persists until 18 mo. METHODS: A prospective, double-blind, randomized control study was conducted. Three groups were formed: a control (CF; n = 169), an LC-PUFA-supplemented (LF; n = 146) and a breastfed (BF; n = 159) group. Information on potential confounders was collected at enrolment. At the age of 18 mo, neurodevelopmental condition was assessed by the age-specific neurological examination of Hempel and the Bayley scales. The Hempel assessment resulted in a clinical neurological diagnosis, a total optimality score and a score on the fluency of motility. The Bayley scales resulted in mental and psychomotor developmental indices. Attrition at 18 mo was 5.5% and non-selective. Multivariate regression analyses were carried out to evaluate the effect of type of feeding while adjusting for confounders. RESULTS: None of the children had developed cerebral palsy and 23 (CF: n = 8; LF: n = 10; BF: n = 5) showed minor neurological dysfunction. The groups did not show statistically significant differences in clinical neurological condition, neurological optimality score, fluency score, and the psychomotor and mental development indices. Multivariate analysis confirmed that there was no effect of type of feeding on neurological condition. CONCLUSION: This study indicates that the beneficial neurodevelopmental effect of 2 mo LC-PUFA supplementation in healthy term infants can not be detected at the age of 18 mo.

Exclusive breastfeeding of healthy term infants for at least 6 weeks improves neurological condition.

To investigate the minimal duration of exclusive breastfeeding for optimal neurological outcome, we assessed the quality of general movements (GM) at 3 mo of 147 breastfed healthy term infants that were followed from birth. The quality of GM is a sensitive marker of neurological condition. The quality of GM was classified as normal-optimal, normal-suboptimal, mildly abnormal and definitely abnormal. Information on social and pre- and perinatal conditions and the duration of breastfeeding was collected prospectively. Logistical regression analyses were used to adjust for confounders. There was a positive association between breastfeeding duration and movement quality, with a saturation effect at the age of approximately 6 wk. In the group of infants breastfed for < or = 6 wk (n = 55), 18% exhibited normal-optimal GM, 47% normal-suboptimal GM, and 47% mildly abnormal GM. In contrast, in the group of infants breastfed for > 6 wk (n = 92), 43% exhibited normal-optimal GM, 45% normal-suboptimal GM, and 12% mildly abnormal GM. Exclusive breastfeeding for >6 wk was therefore associated with markedly less abnormal and more normal-optimal GM. Thus, we conclude that breastfeeding for > 6 wk might improve the neurological condition in infants.

Fatty acids in formulae for term infants: compliance of present recommendations with the actual human milk fatty acid composition of geographically different populations.

AIM: Recommendations for formula fatty acids (FA) are largely based on the mature human milk FA composition. This study aimed to investigate whether current recommendations for formula FA for term infants comply with the actual breast-milk FA composition of geographically distinct populations and to provide more realistic grounds for future recommendations. METHODS: 455 mature breast-milk samples were collected in different countries over 25 y. Recommendations of different organizations were projected on their FA data. FA interrelationships were calculated with Spearman's rank tests. FA compositions of 30 formulae were compared with those of breast milk. RESULTS: Many samples from non-Western communities did not meet the recommendations for formula 12:0, 14:0 and 18:2omega6, since these are mainly based on breast milk of mothers living in Western countries. Recommendations for 18:3omega3, 18:2omega6/18:3omega3, 20:4omega6 and 22:6omega3 were not met by many milk samples, which may point to the poorly developed recommendations for long-chain polyunsaturated FA. Most of the investigated breast-milk FA (12:0, 14:0, 16:0, 18:0, 18:3omega3, 22:6omega3, 18:2omega6, 20:4omega6, 18:1omega9) were either positively or negatively interrelated. Many formulae had FA compositions that were not consistent with the physiological interrelationships of FA in breast milk. CONCLUSION: Future recommendations, if based on human milk, should derive from its FA balance, as indicated by the FA interrelationships. A "humanized" formula FA composition would in this sense be any composition that cannot be distinguished from that of breast milk by techniques such as principal component analysis.

Growth patterns and survival rates of twins in a rural area of Ghana: a follow-up study from birth to adulthood.

This prospective and descriptive study was conducted to evaluate the growth and survival of twins during childhood and adolescence in the Agogo area of Ghana. It describes the outcome in 422 twin children born between 1969 and 1981. By 3 years of age, 40 (9.5%) of them had not reported again, fifteen of the remaining 382 had died and 367 (96%) were still alive. In 1993 and 2001, at 12-26 years of age, 33 children could not be traced; of the remaining 349 children, 17 more had died and 317 (91%) were still alive. Incremental weight gain in the 1st year of life was approximately 0.17 kg/month less than that of a reference group of USA twins. However, growth velocity was similar in the 2nd and 3rd years. From 6 to 36 months of age, Agogo twins were 0.9-1.3 kg lighter than a reference group of Agogo singletons. In both males and females, the physiological growth spurt of puberty occurred approximately 2 years later than in Agogo singletons. By adulthood, mean heights and weights, particularly of female twins, still lagged behind those of the local reference group. Twins have a good chance of surviving childhood although they can be considered to be at high risk, particularly during the 1st year of life. Up to adulthood, growth potential seems to be less than that of their singleton counterparts.

Assessment of essential fatty acid and omega3-fatty acid status by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3.

BACKGROUND: Early suspicion of essential fatty acid deficiency (EFAD) or omega3-deficiency may rather focus on polyunsaturated fatty acid (PUFA) or long-chain PUFA (LCP) analyses than clinical symptoms. We determined cut-off values for biochemical EFAD, omega3-and omega3/22:6omega3 [docosahexaenoic acid (DHA)]-deficiency by measurement of erythrocyte 20:3omega9 (Mead acid), 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3, respectively. METHODS: Cut-off values, based on 97.5 percentiles, derived from an apparently healthy omnivorous group (six Dominica breast-fed newborns, 32 breast-fed and 27 formula+LCP-fed Dutch low-birth-weight infants, 31 Jerusalem infants, 33 Dutch 3.5-year-old infants, 69 omnivorous Dutch adults and seven Dominica mothers) and an apparently healthy group with low dietary LCP intake (81 formula-fed Dutch low-birth-weight infants, 12 Dutch vegans). Cut-off values were evaluated by their application in an EFAD suspected group of 108, mostly malnourished, Pakistani children, three pediatric patients with chronic fat-malabsorption (abetal-ipoproteinemia, congenital jejunal and biliary atresia) and one patient with a peroxisomal beta-oxidation disorder. RESULTS: Erythrocyte 20:3omega9, 22:5omega6/20:4omega6 and 22:5omega6/22:6omega3 proved age-dependent up to 0.2 years. Cut-off values for ages above 0.2 years were: 0.46mol% 20:3omega9 for EFAD, 0.068mol/mol 22:5omega6/20:4omega6 for omega3-deficiency, 0.22mol/mol 22:5omega6/22:6omega3 for omega3/DHA-marginality and 0.48mol/mol 22:5omega6/22:6omega3 for omega3/DHA-deficiency. Use of RBC 20:3omega9 and 22:5omega6/20:4omega6 cut-off values identified 20.4% of the Pakistani subjects as EFAD+omega3-deficient, 12.9% as EFAD+omega3-sufficient, 38.9% as EFA-sufficient+omega3-deficient and 27.8% as EFA-sufficient+omega3-sufficient. The patient with the peroxisomal disorder was classified as EFA-sufficient, omega3-sufficient (based on RBC 22:5omega6/20:4omega6) and omega3/DHA-deficient (based on RBC 22:5omega6/22:6omega3). The three other pediatric patients were classified as EFAD, omega3-deficient and omega3/DHA-deficient. CONCLUSION: Use of the combination of the present cut-off values for EFA, omega3 and omega3/DHA status assessment, as based on 97.5 percentiles, may serve for PUFA supplement intervention until better concepts have emerged.

Perinatal predictors of respiratory symptoms and lung function at a young adult age.

A longitudinal cohort of 2,957 babies, born in 1975-1978, was used to investigate whether perinatal factors predict respiratory morbidity at a young adult age. In 1997, the presence of asthmatic (wheeze, nocturnal dyspnoea) and bronchitic (cough, phlegm, dyspnoea grade 3) symptoms and the level of lung function was determined in this cohort. The independent association between smoking during pregnancy, being first-born, birth weight and respiratory symptoms and lung function at young adult age was investigated using multiple regression models, taking other potential risk factors into account. Of 1,568 responders, 608 (39%, aged 18-22 yrs) had at least one respiratory symptom. The young adults who had a mother that smoked during pregnancy had a significantly lower level of lung function than their nonintra-uterine exposed peers (regression coefficient (B) (standard error): peak expiratory flow (PEF) -0.257 (0.131) L x s(-1); forced expiratory flow when 25% of the forced vital capacity has been exhaled (FEF25) -0.290 (0.129) L x s(-1)), although they were not at increased risk of having respiratory symptoms. Young adults who were first-born had better levels of lung function (B (SE): forced expiratory volume in one second (FEV1) 0.090 (0.042) L) and were less likely to have asthmatic symptoms (odds ratio (95%, confidence interval): 0.58 (0.35-0.95)) than those not first-born. Low birth weight (FEV1 -0.013 (0.004) L for a reduction of 100 g) was also predictive of reduced achieved levels of lung function at young adult age, independent of other potential risk factors, e.g. current smoking habits or familial predisposition. This study adds to the knowledge of the role of perinatal factors, such as smoking during pregnancy, as important predictors of respiratory morbidity.

Estimated biological variation of the mature human milk fatty acid composition.

We estimated the biological variation (CV(biol)) of 28 fatty acids (FA) in 465 mature human milk samples from The Netherlands, Caribbean, Jerusalem, Tanzania and Pakistan, by using data from the observed variation (CV(obs)) and analytical variation (CV(anal)). CV(biol) of the various regions was remarkably similar. The average CV(biol) of 455 samples, Pakistan excluded, ranged from 12.7% for 16:0 and 18.9% for 18:1 omega 9 to 68% for 22:6 omega 3 and about 100% for 20:5 omega 3. Those of 20:4 omega 6, 18:2 omega 6 and 18:3 omega 3 were 28.0, 33.0 and 37.3%, respectively. Because of the large CV(biol) and the many dietary changes in recent history, it seems impossible to consider the present human milk FA composition as the 'gold standard' for infant formula. Optimal human milk FA composition should rather derive from populations that consume traditional diets or from the scientific data that show the function of the individual FAs in neonatal development.

Levels of certain metals, organochlorine pesticides and dioxins in cord blood, maternal blood, human milk and some commonly used nutrients in the surroundings of the Aral Sea (Karakalpakstan, Republic of Uzbekistan).

UNLABELLED: Since the 1960s a massive decline in the volume of the Aral Sea has occurred as a result of the diversion of the supplying rivers to cotton irrigation schemes. The contaminated sediment of the former seabed has been disseminated over the surrounding area by strong winds. This deterioration of the ecosystem has created a hazardous situation for the health of approximately 3.5 million people. This pilot study was undertaken to assist Karakalpak health workers in investigating the degree of exposure to metals, persistent organochlorine pesticides (OCPs) and dioxins during the most vulnerable prenatal and postnatal period and to provide guidelines for future research. All subjects came from areas located within 200 km of the southern border of the Aral Sea. Blood was obtained from 18 pregnant women and 28 newborns (cord blood) to determine the levels of metals, lead, cadmium, zinc and selenium and the OCPs alpha-, beta- and gamma-hexachlorocyclohexane (HCH; lindane is the product name of gamma-hexachlorocyclohexane), hexachlorobenzene (HCB), and isomers and metabolites of dichlorodiphenyltrichloroethane (DDT), i.e. op-DDT, pp-DDT, pp-DDE and pp-TDE. Levels of metals were also determined in blood from 28 non-pregnant women. In addition, levels of 17 dioxins were determined in 41 human milk samples and 1batch of formula. Information about possible dietary sources of the fat-soluble OCPs and dioxins was obtained from a pooled sample of butter and from seven cottonseed oil samples. A mass-selective detector coupled to a gas chromatograph equipped with a large volume injector was used to analyse the selected OCPs, whereas the dioxins were determined by gas chromatography with high-resolution mass spectrometry. The levels of metals in cord and maternal blood were consistent with concentrations observed in European countries. Only three women (7%) had lead levels greater than 100 ppb. The most notable pollutants in maternal and cord blood were the OCPs, notably HCB, beta-HCH, pp-DDE and the most toxic dioxin, 2,3,7,8-TCDD, when calculated as TEQs. A similar pattern was observed in human milk: beta-HCH and pp-DDE levels of more than 1,000 ng g(-1) fat were found in 68 and 43% of the subjects, respectively. Levels of 2,3,7,8-TCDD were six times higher than those observed in Western Europe. Traces of pp-DDE were detected in the batch of formula milk. Contaminated animal fat, but not cottonseed oil, is the most likely dietary source of OCPs and dioxins. CONCLUSION: Further epidemiological research is needed to elucidate the health implications of these pollutants on perinatal and maternal health, including lactation. More importantly, an investigation should be initiated to identify the emission sources of persistent organic pollutants in Karakalpakstan and adjacent regions.

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.

Growth and survival of low birthweight infants from 0 to 9 years in a rural area of Ghana. Comparison of moderately low (1,501-2,000 g) and very low birthweight (1,000-1,500 g) infants and a local reference population.

This prospective and descriptive study was conducted to evaluate the growth and survival of 105 low birthweight (LBW, 1,000-2,000 g) infants discharged during a 4-year period from Agogo Hospital, Ghana, and followed from birth until the age of 4-9 years. Thirty-two babies were very low birthweight children (VLBW, 1,000-1,500 g) and 73 (70%) were of moderately low birthweight (MLBW, 1,501-2,000 g). At the age of 3 years, 15 children (14.2%) had not come for follow-up; of the remaining 90 children, nine (10%) had died, five during the first 3 months of life. At follow-up from 4 to 9 years of age, two more children could not be traced and another two had died. Compared to a local reference population and the WHO standard, growth of survivors lagged behind and caught up only slightly during the first 3 years of life. From 3 to 9 years of age, median growth impairment increased, which either suggests impaired growth potential or poor health and inadequate nutrition. This long-term study confirms that LBW (1,000-2,000 g) infants, particularly VLBW children, are at high risk.

Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition.

We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), or a combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg eicosapentaenoic acid (20:5 omega 3; EPA) and 400 mg DHA, for one week and eight women served as unsupplemented controls. Milk samples were collected on days 0, 1 and 7. The fatty acid composition of the milk was analyzed by capillary gas chromatography with flame ionisation detection. Supplementation with AA alone had no effect on breastmilk AA, but tended to reduce EPA and DHA levels. Administration of a combination of AA, EPA and DHA tended to increase both milk AA and long chain PUFA (LCPUFA)omega 3 content. A larger simultaneous increase of milk AA, DHA and EPA than observed in the present study can probably be accomplished by the use of a combination of a lower LCPUFA omega 6/LCPUFA omega 3 ratio and higher AA, EPA and DHA dosages.

Breast milk docosahexaenoic acid (DHA) correlates with DHA status of malnourished infants.

AIM: To investigate whether low docosahexaenoic acid (22:6omega3; DHA) status of malnourished, mostly breast fed infants is a result of low omega3 fatty acid intake via breast milk. METHODS: Fatty acid composition of breast milk of eight Pakistani mothers, and of the erythrocytes of their malnourished children was analysed. RESULTS: The milk of the Pakistani mothers contained low percentages of all omega3 and most omega6 fatty acids, compared with milk of Dutch mothers. Breast milk DHA was positively correlated with infant erythrocyte DHA and arachidonic acid (20:4omega6). CONCLUSION: DHA status of these malnourished children is strongly dependent on the omega3 fatty acid intake from breast milk. Augmentation of the infants' omega3 long chain polyunsaturated fatty acid status, or the omega3 and omega6 fatty acid status in general, by supplementation is indicated in deprived circumstances where access to fresh fish is difficult. However, in terms of prevention, maternal supplementation of these long chain polyunsaturated fatty acids, preferably from early pregnancy onwards, may be a better option.

Fish oil supplementation improves docosahexaenoic acid status of malnourished infants.

AIM: To investigate whether the low docosahexaenoic acid (DHA) status of malnourished, mostly breast fed, Pakistani children can be improved by fish oil (FO) supplementation. METHODS: Ten malnourished children (aged 8-30 months) received 500 mg FO daily for nine weeks. The supplement contained 62.8 mol% (314 mg) long chain polyunsaturated fatty acids of the omega3 series (LCPUFAomega3) and 22.5 mol% (112 mg) DHA. Seven FO unsupplemented children served as controls. Red blood cell (RBC) fatty acids were analysed at baseline and at the study end. RESULTS: FO supplementation augmented mean (SD) RBC DHA from 2.27 (0.81) to 3.35 (0.76) mol%, without significantly affecting the concentrations of LCPUFAomega6. Unsupplemented children showed no RBC fatty acid changes. One FO supplemented child with very low initial RBC arachidonic acid showed a remarkable increase from 4.04 to 13.84 mol%, whereas another with high RBC arachidonic acid showed a decrease from 15.64 to 10.46 mol%. CONCLUSION: FO supplementation improves the DHA status of malnourished children. The supplement is apparently well absorbed and not exclusively used as a source of energy.

Low erythrocyte docosahexaenoic acid in malnourished, often breast-fed, Pakistani infants: a matter of concern?

PIP: This article provides valuable information on the importance of long-chain polyunsaturated fatty acids (LCPUFAs) for the development of the central nervous system, including visual acuity. It was believed that breast milk contains a large range of LCPUFAs, including docosahexaenoic (DHA) and arachidonic acids which cannot be found in formula milks for term infants; but low RBC LCPUFAs have been observed in malnourished children receiving breast milk and weaning food low in fat. In these children, it has been postulated that the synthesis of LCPUFAs from their precursors is decreased making them more dependent on an adequate LCPUFA intake. Several studies were conducted to test this hypothesis. It was observed that although malnourished children in North Pakistan received breast milk, yet poor DHA status of these malnourished breastfed children is caused by a marginal DHA status of these mothers. Further studies are needed though to establish the relationship between maternal nutrition during lactation and children RBC DHA levels receiving breast milk.^ieng

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.