Neurodevelopmental outcomes at five years after early-onset fetal growth restriction: Analyses in a Dutch subgroup participating in a European management trial.

OBJECTIVE: The objective of this study is to explore developmental outcomes at five years after early-onset fetal growth restriction (FGR). STUDY DESIGN: Retrospective data analysis of prospective follow-up of patients of three Dutch centres, who participated in a twenty centre European randomized controlled trial on timing of delivery in early-onset FGR. Developmental outcome of very preterm infants born after extreme FGR is assessed at (corrected) age of five. RESULTS: Seventy-four very preterm FGR children underwent follow-up at the age of five. Mean gestational age at birth was 30 weeks and birth weight was 910 g, 7% had a Bayley score <85 at two years. Median five years' FSIQ was 97, 16% had a FSIQ < 85, and 35% had one or more IQ scores <85. Motor score ≤ 7 on movement ABC-II (M-ABC-II-NL) was seen in 38%. Absent or reversed end-diastolic flow, gestational age at delivery, birthweight and neonatal morbidity were related to an FSIQ < 85. Any abnormal IQ scale score was related to birthweight, male sex and severity of FGR, and abnormal motor score to male sex and bronchopulmonary dysplasia (BPD). CONCLUSIONS: Overall, median cognitive outcome at five years was within normal range, but 35% of the children had any abnormal IQ score at age five, depending on the IQ measure, and motor impairment was seen in 38% of the children. GA at delivery, birthweight, EDF prior to delivery and neonatal morbidity were the most important risk factors for cognitive outcomes.

[Two-year follow-up of infants born at 24 weeks gestation; first outcomes following implementation of the new 'Guideline for perinatal policy in cases of extreme prematurity']. / Follow-up na 2 jaar van kinderen geboren bij 24 weken.

OBJECTIVE: Since 2010 the guideline 'Guideline for perinatal policy in cases of extreme prematurity' has advised an active policy in infants born at 24 weeks gestation. We investigated how infants born at 24 and 25 weeks gestation in the first year following the implementation of the guideline had developed by the age of 2 years. DESIGN: Retrospective national cohort study. METHOD: The study population consisted of all surviving infants born in the Netherlands at 24 or 25 weeks gestation in the period from 1 October 2010 to 1 October 2011. At a corrected age of 2 years the children underwent a general physical and neurological examination, and their cognitive scores were determined on the 'Bayley scales of infant and toddler development' (Bayley III). Examinations took place in the 10 neonatal intensive care units (NICU's) in the Netherlands. RESULTS: Of 185 extremely premature infants, 166 were admitted to a NICU. A total of 95 survived to a corrected age of 2 years; 78 (82%) children were examined. Their average cognitive score on the Bayley III scale was 88 (SD: 16). Among the children born at 24 weeks gestation, 20% had mild disabilities and 20% had moderate to severe disabilities. Among the children born at 25 weeks gestation, 17% had mild disabilities and 12% had moderate to severe disabilities. CONCLUSION: Of the children born at 24 weeks gestation in the first year after the introduction of active policy in the Netherlands and surviving to 2 years of age (46%), more than half had developed without disabilities. This was comparable to children born at 25 weeks gestation. Of all children born at 24 weeks gestation, 25% survived to 2 years of age without disabilities.

Cost-effectiveness of embryo transfer strategies: a decision analytic model using long-term costs and consequences of singletons and multiples born as a consequence of IVF.

STUDY QUESTION: What is the cost-effectiveness of elective single embryo transfer (eSET) versus double embryo transfer (DET) strategies from a societal perspective, when applying a time horizon of 1, 5 and 18 years? SUMMARY ANSWER: From a short-term perspective (1 year) it is cost-effective to replace DET with single embryo transfer; however when intermediate- (5 years) and long-term (18 years) costs and consequences are incorporated, DET becomes the most cost-effective strategy, given a ceiling ratio of €20 000 per quality-adjusted life years (QALY) gained. WHAT IS ALREADY KNOWN: According to previous cost-effectiveness research into embryo transfer strategies, DET is considered cost-effective if society is willing to pay around €20 000 for an extra live birth. However, interpretation of those studies is complicated, as those studies fail to incorporate long-term costs and outcomes and used live birth as a measure of effectiveness instead of QALYs. With this outcome, both multiple and singletons were valued as one live birth, whereas costs of all children of a multiple were incorporated. STUDY DESIGN, SIZE, DURATION: A Markov model (cycle length: 1 year; time horizon: 1, 5 and 18 years) was developed comparing a maximum of: (i) three cycles of eSET in all patients; (ii) four cycles of eSET in all patients; (iii) five cycles of eSET in all patients; (iv) three cycles of standard treatment policy (STP), i.e. eSET in women <38 years with a good quality embryo, and DET in all other women; and (v) three cycles of DET in all patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Expected life years (LYs), child QALYs and costs were estimated for all comparators. Input parameters were derived from a retrospective cohort study, in which hospital resource data were collected (n=580) and a parental questionnaire was sent out (431 respondents). Probabilistic sensitivity analysis (5000 iterations) was performed. MAIN RESULTS AND THE ROLE OF CHANCE: With a time horizon of 18 years, DETx3 is most effective (0.54 live births, 10.2 LYs and 9.8 QALYs) and expensive (€37 871) per couple starting IVF. Three cycles of eSET are least effective (0.43 live births, 7.1 LYs and 6.8 QALYs) and expensive (€25 563). We assumed that society is willing to pay €20 000 per QALY gained. With a time horizon of 1 year, eSETx3 was the most cost-effective embryo transfer strategy with a probability of being cost-effective of 99.9%. With a time horizon of 5 or 18 years, DETx3 was most cost-effective, with probabilities of being cost-effective of 77.3 and 93.2%, respectively. LIMITATIONS, REASONS FOR CAUTION: This is the first study to use QALYs generated by the children in the economic evaluation of embryo transfer strategies. There remains some disagreement on whether QALYs generated by new life should be used in economic evaluations of fertility treatment. A further limitation is that treatment ends when it results in live birth and that only child QALYs were considered as measure of effectiveness. The results for the time horizon of 18 years might be less solid, as the data beyond the age of 8 years are based on extrapolation. WIDER IMPLICATIONS OF THE FINDINGS: The current Markov model indicates that when child QALYs are used as measure of outcome it is not cost-effective on the long term to replace DET with single embryo transfer strategies. However, for a balanced approach, a family-planning perspective would be preferable, including additional treatment cycles for couples who wish to have another child. Furthermore, the analysis should be extended to include QALYs of family members. STUDY FUNDING/COMPETING INTERESTS: This study was supported by a research grant (grant number 80-82310-98-09094) from the Netherlands Organization for Health Research and Development (ZonMw). There are no conflicts of interest in connection with this article. TRIAL REGISTRATION NUMBER: Not applicable.

Placental pathology and outcome after perinatal asphyxia and therapeutic hypothermia.

OBJECTIVE: To assess the relationship between placental pathology, pattern of brain injury and neurodevelopmental outcome in term infants with perinatal asphyxia receiving therapeutic hypothermia. STUDY DESIGN: Studies were performed in 76 infants. Death or survival with impairments at 18 to 24 months was used as a composite adverse outcome. Multivariable analysis was performed. RESULTS: Among the 75 infants analyzed, the predominant pattern of brain injury was: no injury (n=27), a white matter/watershed pattern (n=14), basal-ganglia-thalamic injury (n=13) or near-total brain injury (n=21). An adverse outcome was seen in 35 of the 76 infants. Elevated nucleated red blood cells were associated with white matter involvement. Small placental infarcts were more common among infants without brain injury. All other placental abnormalities were not related to both outcome measures. CONCLUSION: In our population of term infants receiving therapeutic hypothermia, no type of placental pathology was related to extensive brain injury or adverse neurodevelopmental outcome.

Hospital costs during the first 5 years of life for multiples compared with singletons born after IVF or ICSI.

STUDY QUESTION: Do in vitro fertilization (IVF) multiples generate higher hospital costs than IVF singletons, from birth up to age 5? SUMMARY ANSWER: Hospital costs from birth up to age 5 were significantly higher among IVF/ICSI multiple children compared with IVF/ICSI singletons; however, when excluding the costs incurred during the birth admission period, hospital costs of multiples and singletons were comparable. WHAT IS KNOWN ALREADY: Concern has risen over the long-term outcome of children born after IVF. The increased incidence of multiple births in IVF as a result of double-embryo transfer predisposes children to a poorer neonatal outcome such as preterm birth and low birthweight. As a consequence, IVF multiples require more medical care. Costs and consequences of poorer neonatal outcomes in multiples may also exist later in life. STUDY DESIGN, SIZE, DURATION: All 5497 children born from IVF in 2003-2005, whose parents received IVF or ICSI treatment in one of five participating Dutch IVF centers, served as a basis for a retrospective cohort study. Based on gestational age, birthweight, Apgar and congenital malformation, children were assigned to one of three risk strata (low-, moderate- or high-risk). PARTICIPANTS/MATERIALS, SETTING, METHODS: To enhance the efficiency of the data collection, 816 multiples and 584 singletons were selected for 5-year follow-up based on stratified (risk) sampling. Parental informed consent was received of 322 multiples and 293 singletons. Individual-level hospital resource use data (hospitalization, outpatient visits and medical procedures) were retrieved from hospital information systems and patient charts for 302 multiples and 278 singletons. MAIN RESULTS AND THE ROLE OF CHANCE: The risk of hospitalization (OR 4.9, 95% CI 3.3-7.0), outpatient visits (OR 2.6, 95% CI 1.8-3.6) and medical procedures (OR 1.7, 95% CI 1.2-2.2) was higher for multiples compared with singletons. The average hospital costs amounted to €10 018 and €2093 during the birth admission period (P < 0.001), €1131 and €696 after the birth admission period to the first birthday (not significant (n.s.)) and €1084 and €938 from the second to the fifth life year (n.s.) for multiples and singletons, respectively. Hospital costs from birth up to age 5 were 3.3-fold higher for multiples compared with singletons (P < 0.001). Among multiples and singletons, respectively, 90.8 and 76.2% of the total hospital costs were caused by hospital admission days and 8.9 and 25.2% of the total hospital costs during the first 5 years of life occurred after the first year of life. LIMITATIONS, REASONS FOR CAUTION: Resource use and costs outside the hospital were not included in the analysis. WIDER IMPLICATIONS OF THE FINDINGS: This study confirms the increased use of healthcare resources by IVF/ICSI multiples compared with IVF/ICSI singletons. Single-embryo transfer may result in substantial savings, particularly in the birth admission period. These savings need to be compared with the extra costs of additional embryo transfers needed to achieve a successful pregnancy. Besides costs, health outcomes of children born after single-embryo transfer should be compared with those born after double-embryo transfer. STUDY FUNDING/COMPETING INTERESTS: This study was supported by a research grant (grant number 80-82310-98-09094) from the Netherlands Organization for Health Research and Development (ZonMw). There are no conflicts of interest in connection with this article. TRIAL REGISTRATION NUMBER: Not applicable.

Perinatal mortality and mode of delivery in monochorionic diamniotic twin pregnancies ≥ 32 weeks of gestation: a multicentre retrospective cohort study.

OBJECTIVE: To study perinatal mortality rates in a cohort of 465 monochorionic (MC) twins without twin-twin transfusion syndrome (TTS) born at 32 weeks of gestation or later since reported interauterine fetal death (IUFD) rates >32 weeks of gestations in the literature vary, leading to varying recommendations on the optimal timing of delivery, and to investigate the relation between perinatal mortality and mode of delivery. DESIGN: Multicentre retrospective cohort study. SETTING: Ten perinatal referral centres in the Netherlands. POPULATION: All MC twin pregnancies without TTTS delivered at ≥ 32 weeks of gestation between January 2000 and December 2005. METHODS: The medical records of all MC twin pregnancies without TTTS delivered at the ten perinatal referral centres in the Netherlands between January 2000 and December 2005 were reviewed. MAIN OUTCOME MEASURES: Perinatal mortality in relation to gestational age and mode of delivery at ≥ 32 weeks of gestation. RESULTS: After 32 weeks of gestation, five out of 930 fetuses died in utero and there were six neonatal deaths (6 per 1000 infants). In women who delivered ≥ 37 weeks, perinatal mortality was 7 per 1000 infants. Trial of labour was attempted in 376 women and was successful in 77%. There were three deaths in deliveries with a trial of labour (8 per 1000 deliveries), of which two were related to mode of delivery. Infants born by caesarean section without labour had an increased risk of neonatal morbidity and respiratory distress syndrome. CONCLUSIONS: In MC twin pregnancies the incidence of intrauterine fetal death is low ≥ 32 weeks of gestation. Therefore, planned preterm delivery before 36 weeks does not seem to be justified. The risk of intrapartum death is also low, at least in tertiary centres.

Placental characteristics of monochorionic diamniotic twin pregnancies in relation to perinatal outcome.

To study placental characteristics in relation to perinatal outcome in 150 pairs of monochorionic diamniotic (MCDA) twins. Between January 1998 and January 2007 150 pairs of MCDA twins were delivered in the University Medical Center, Utrecht, The Netherlands. Mortality, neonatal morbidity and birth weight discordancy were studied in relation to type of anastomoses, type and distance between cord insertions and placental sharing. From 14 weeks onwards, there were 45 (15.0%) perinatal deaths. We found no clear relationship between perinatal mortality and type of anastomoses, distance between cord insertions and placental sharing. Perinatal mortality was significantly increased in the presence of velamentous cord insertion (OR 3.65, 95% CI 1.83-7.28). Data concerning neonatal morbidity were similar. TTTS occurred predominantly in the presence of AV-anastomoses without compensating superficial AA-anastomoses (p=0.005) and occurred more frequently in the presence of velamentous cord insertion (OR 1.79, 95% CI 0.94-3.44). Twins with unequal shared placentas had significantly more often severe birth weight discordancy, although only in the presence of AA-anastomoses (OR 4.09, 95% CI 1.74-9.63). If AA-anastomoses were absent in the unequally shared placenta, there was no relation between severe birth weight discordancy and unequal sharing of the placenta (OR 1.06, 95% CI 0.08-13.52). In MCDA twins, placental characteristics determine perinatal outcome, occurrence of TTTS and fetal growth. Prenatal identification of these characteristics by ultrasound may alter counselling and intensity of pregnancy surveillance.

Increased perinatal mortality and morbidity in monochorionic versus dichorionic twin pregnancies: clinical implications of a large Dutch cohort study.

OBJECTIVE: To evaluate mortality and morbidity in a large cohort of twin pregnancies according to chorionicity. We aimed to estimate the optimal time of delivery. DESIGN: Historical cohort design. Setting Two teaching hospitals. POPULATION: Twin pregnancies delivered in the University Medical Centre, Utrecht, and the St Elisabeth Hospital, Tilburg (1995-2004), The Netherlands (n = 1407). METHODS: Pregnancy outcomes were documented according to chorionicity. Mortality >/=32 weeks was reviewed carefully with special attention to antenatal fetal monitoring, autopsy and placental histopathology to find an explanation for adverse outcome. MAIN OUTCOME MEASURES: Perinatal mortality and morbidity in monochorionic (MC) and dichorionic (DC) twins. RESULTS: Perinatal mortality was 11.6% in MC twin pregnancies and 5.0% in DC twin pregnancies. After 32 weeks, the risk of intrauterine death (IUD) was significantly higher in MC twins than in DC twins (hazard ratio 8.8, 95% CI 2.7-28.9). In most of these cases of IUD, no antenatal signs of impaired fetal condition had been present. Median gestational age was 1 week longer in DC twins than in MC twins, and the mean birthweight was 221 g higher. Severe birthweight discordancy (>20%) occurred more often in MC twins than in DC twins (OR 1.23, 95% CI 0.97-1.55). The incidence of necrotising enterocolitis (NEC) was higher in MC twins, after adjustment for age and weight at birth (OR 4.05, 95% CI 1.97-8.35). There was a trend towards higher neuromorbidity in MC twins. CONCLUSIONS: This is the largest cohort study of twin pregnancies evaluating outcome according to chorionicity thus far. MC twins are at increased risk for fetal death (even at term), NEC and neuromorbidity. Current antenatal care is insufficient to predict and prevent this excess perinatal mortality and morbidity. Planned delivery at or even before 37 weeks of gestation seems to be justified for MC twins.

Effects of environmental exposure to polychlorinated biphenyls and dioxins on birth size and growth in Dutch children.

Lower birth weight and growth retardation has been found in studies with laboratory animals, in children born of mothers exposed to accidental high levels of polychlorinated biphenyls (PCBs) and related compounds, and in children born of mothers who consumed PCB-contaminated fish. The effect of background exposure to PCBs and dioxins on birth size and growth in human newborns, however, is still unknown. This study examined birth size and postnatal growth of term newborns in relation to their background PCB and dioxin exposure. Birth weight and weight, length, and head circumference were measured at 10 d and 3, 7, 18, and 42 mo of age in 207 children, of whom 105 were breast-fed and 102 were formula-fed during infancy. The effect of in utero exposure to PCBs on birth size, assessed by cord and maternal plasma PCB levels, was investigated in the whole group. The effect of prenatal PCB exposure on postnatal growth was studied in the formula-fed group, whereas the effect of prenatal as well as lactational exposure to PCBs and dioxins on postnatal growth was studied in the breast-fed group. After adjustment for covariates, cord and maternal plasma PCB levels where both negatively associated with birth weight. Infants with high cord plasma PCB levels (P90 = 0.80 microL) weighed 165 g less compared with infants with low cord plasma PCB levels (P10 = 0.20 microg/L). Cord and maternal plasma PCB levels where both significantly associated with lower growth rate, defined as change in SD score (SDS) of weight, length, and head circumference from birth to 3 mo in the formula-fed group (all p values <0.05). No negative effects of prenatal PCB exposure on growth rate were found from 3 to 42 months of age. Postnatal PCB and dioxin exposure was not negatively associated with growth rate in the breast-fed group. In utero exposure to environmental levels of PCBs is negatively associated with birth weight and postnatal growth until 3 mo of age. Although this growth delay was described in healthy term born infants, intrauterine and postnatal growth retardation are potentially harmful to the developing human and should be avoided by reducing maternal PCB and dioxin body burden, and consequently fetal exposure to these pollutants.

Plasma polychlorinated biphenyl levels in Dutch preschool children either breast-fed or formula-fed during infancy.

OBJECTIVES: This study examined the influence of lactational and in utero exposure to polychlorinated biphenyls (PCBs) on plasma PCB levels in children. METHODS: Plasma PCB levels were measured in 173 children at 3.5 years, of whom 91 were breast-fed and 82 were formula-fed in infancy. RESULTS: Median plasma PCB levels were 3.6 times higher in breast-fed children (0.75 microgram/L) than in their formula-fed peers (0.21 microgram/L). Breast-feeding period and breast-milk PCB levels were important predictors for PCB levels in the breast-fed group. For children in the formula-fed group, PCB levels were significantly related to their material plasma PCB levels. CONCLUSIONS: PCB levels in Dutch preschool children are related to transfer of maternal PCBs; therefore, strategies should be aimed at reducing maternal PCB body burden.

Effects of polychlorinated biphenyl/dioxin exposure and feeding type on infants' mental and psychomotor development.

OBJECTIVE: To evaluate the effects of in utero and lactational exposure to polychlorinated biphenyls (PCBs) and dioxins on the mental and psychomotor development of infants. DESIGN: Prenatal PCB exposure was estimated from the levels in maternal plasma during the last month of pregnancy. Postnatal PCB and dioxin exposure of breastfed infants was calculated from levels in human milk samples and the duration of breastfeeding. Infants were examined at 3, 7, and 18 months of age with the Bayley Scales of Infant Development. SETTING: General community. PARTICIPANTS: Voluntary sample of 207 mother-infant pairs. One hundred five infants were breastfed and 102 were bottle-fed. INTERVENTIONS: None. RESULTS: Higher in utero exposure to PCBs was associated with lower psychomotor scores at 3 months of age: a doubling of the PCB load resulted in a decrease of 3 points. Breastfed infants scored significantly higher on the psychomotor score at 7 months of age, compared with formula-fed infants. However, when corrected for confounders, the psychomotor score of the 66% highest-exposed breastfed infants ( > 756 pg total PCB-dioxin toxic equivalent) was negatively influenced by this postnatal exposure to PCBs and dioxins, and was comparable to the psychomotor score of the formula-fed infants. Breastfed infants also scored higher on the mental scale at 7 months of age in a dose-dependent way. There was no significant influence of the perinatal PCB and dioxin exposure on the mental outcome at 3 and 7 months of age. At 18 months of age neither the mental nor the psychomotor score was related to perinatal PCB or dioxin exposure, nor to the duration of breastfeeding. CONCLUSIONS: Prenatal PCB exposure has a small negative effect on the psychomotor score at 3 months of age. PCB and dioxin exposure through breastfeeding has an adverse effect on the psychomotor outcome at 7 months of age. The mental outcome at 7 months of age is positively influenced by breastfeeding per se; the perinatal exposure to PCBs and dioxins does not influence this outcome. At 18 months of age the development is affected neither by PCB and dioxin exposure nor by feeding type.

Perinatal exposure to polychlorinated biphenyls and dioxins through dietary intake.

Polychlorinated biphenyls (PCBs) and dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans) are potentially hazardous compounds. Since food is the major source (> 90%) for the accumulation of PCBs and dioxins in the human body, food habits in women determine the degree of fetal exposure and levels in human milk. In order to investigate an association between dietary intake and PCB and dioxin levels in human milk and PCB levels in maternal and cord plasma, the food intake of 418 Dutch women during pregnancy was recorded using semi-quantitative food frequency questionnaires. After adjusting for covariates, a weak association was found between the estimated dietary intake of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), dioxins, and planar PCBs and their corresponding levels in breast milk. The estimated dietary intake of 2,3,7,8-TCDD, dioxins, and planar PCBs was also related to the PCB levels in maternal and cord plasma. Dairy products accounted for about half and industrial oils for about a quarter of the estimated 2,3,7,8-TCDD, dioxin, and the planar PCB intake. It is concluded that the contribution of a pregnancy related diet to PCB and dioxin levels in human milk and to PCB levels in maternal and cord plasma is relatively low. Decrease of exposure to PCBs and dioxins of the fetus and the neonate probably requires long-term reduction of the intake of these pollutants. Substitution of normal cheese by low-fat cheese and the use of vegetable oils instead of fish oils in the preparation of foodstuffs by the food industry could contribute to a reduced intake of PCBs and dioxins.

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.

Immunologic effects of background prenatal and postnatal exposure to dioxins and polychlorinated biphenyls in Dutch infants.

Immunologic effects of pre- and postnatal polychlorinated biphenyl (PCB)/dioxin exposure in Dutch infants from birth to 18 mo of age are explored. The total study group consisted of 207 healthy mother-infant pairs, of which 105 infants were breast-fed and 102 children were bottle-fed. Prenatal PCB exposure was estimated by the PCB sum (PCB congeners 118, 138, 153, and 180) in maternal blood and the total toxic equivalent (TEQ) level in human milk (17 dioxin and 8 dioxin-like PCB congeners). Postnatal PCB/dioxin exposure was calculated as a product of the total TEQ level in human milk multiplied by the weeks of breast-feeding. The number of periods with rhinitis, bronchitis, tonsillitis, and otitis during the first 18 mo of life was used as an estimate of the health status of the infants. Humoral immunity was measured at 18 mo of age by detecting antibody levels to mumps, measles, and rubella. White blood cell counts (monocytes, granulocytes, and lymphocytes) and immunologic marker analyses CD4+ T-lymphocytes, CD8+ T-lymphocytes, activated T-lymphocytes (HLA-DR+CD3+), as well as T cell receptor (TcR) alpha beta+, TcR gamma delta+, CD4+CD45RA+ and CD4+CD45RO+ T-lymphocytes, B-lymphocytes (CD19+ and/or CD20+) and NK cells (CD16+ and/or CD56+/CD3-) in cord blood and venous blood at 3 and 18 mo of age were assessed in a subgroup of 55 infants. There was no relationship between pre- and postnatal PCB/dioxin exposure and upper or lower respiratory tract symptoms or humoral antibody production.(ABSTRACT TRUNCATED AT 250 WORDS)

Perinatal exposure to polychlorinated biphenyls and dioxins and its effect on neonatal neurological development.

Polychlorinated biphenyls (PCBs) and dioxins (polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs)) are widespread environmental contaminants which are neurotoxic in animals. Perinatal exposure to PCBs, PCDDs, and PCDFs occurs prenatally via the placenta and postnatally via breast milk. To investigate whether such an exposure affects the neonatal neurological condition, the neurological optimality of 418 Dutch newborns was evaluated with the Prechtl neurological examination. Half of the infants were breast-fed, the other half were formula-fed, representing a relatively high against a relatively low postnatally exposed group, respectively. As an index of prenatal exposure, four non-planar PCBs in cord and maternal plasma were used. These PCB levels were not related to neurological function. As measures of combined pre- and early neonatal exposure, 17 dioxin congeners, three planar, and 23 non-planar PCB congeners were determined in human milk in the second week after delivery. Higher levels of PCBs, PCDDs, and PCDFs in breast milk were related to reduced neonatal neurological optimality. Higher levels of planar PCBs in breast milk were associated with a higher incidence of hypotonia. This study confirms previous reports about the neurotoxic effects of these compounds on the developing brain of newborn infants.

Effects of polychlorinated biphenyls (PCBs) and dioxins on growth and development.

Polychlorinated biphenyls (PCBs) and dioxins are potentially toxic compounds which occur widely in the environment. Their effects on the growth and development of infants at the levels currently found in highly industrialised western countries is not well known. This Dutch multicenter study, combining animal and human studies, tries to answer this question. Animal studies showed that PCB 169, given once during pregnancy at a dose of 1.8 g kg-1 bodyweight, has an effect on developmental parameters, dopamine regulation and fertility. Effects on thyroid hormones were also found in animals, probably due to both a competitive binding of PCB metabolites to the thyroxine binding protein and increased glucuronidation. Perhaps to compensate for this, an increased diodase activity in the brain was found. Human studies involved 400 mother-infant pairs, half of them being breast-fed, the other half were fed a formula devoid of PCBs and dioxins. PCB levels were measured in serum and dioxin and PCB levels in breastmilk. Levels were found to be as high as previously found in highly industrialised countries. Growth and development were carefully documented, but no data are as yet available. In pregnant women, a significant negative correlation was found between some dioxin and PCB congeners in milk and plasma thyroid hormones, while newborn infants showed higher thyroid stimulating hormone (TSH) at higher levels of dioxin exposure. In summary, data from this combined multicenter study involving animals and humans increases our insight into the potentially negative effects of PCBs and dioxins on growth and development.