The evolving continuum of dysglycaemia: Non-diabetic hyperglycaemia in older adults

Identifying non-diabetic hyperglycaemia (NDH) and intervening to halt the progression to type 2 diabetes has become an essential component of cardiovascular and cerebrovascular risk reduction. Diabetes prevention programs have been instigated to address the increasing prevalence of NDH and type 2 diabetes by targeting lifestyle modifications. Evidence suggests that the risk of progression from NDH to type 2 diabetes declines with age, and that a diagnosis of type 2 diabetes in older adults is not associated with the same risk of adverse consequences as it is in younger age groups. The current definition of NDH is not adjusted based on a person's age. Therefore, there is debate about the emphasis that should be placed upon a diagnosis of NDH in older adults. This article will explore the evidence and current clinical practice surrounding dysglycaemia through the spectrum of different age ranges, and the potential implications this has for older adults.

Factors associated with the development of paediatric chronic otitis media by age nine: a prospective longitudinal cohort study of 6560 children

OBJECTIVE

This study aimed to analyse social, health and environmental factors associated with the development of chronic otitis media by age nine.

METHOD

This was a prospective, longitudinal, birth cohort study of 6560 children, reviewed at age nine. Chronic otitis media defined as previous surgical history or video-otoscopic changes of tympanic membrane retraction, perforation or cholesteatoma. Non-affected children were used as the control group.

RESULTS

Univariate analysis demonstrated an association between chronic otitis media and otorrhoea, snoring, grommet insertion, adenoidectomy, tonsillectomy, hearing loss, abnormal tympanograms and preterm birth. Multivariate analysis suggests many of these factors may be interrelated.

CONCLUSION

The association between chronic otitis media and otorrhoea, abnormal tympanograms and grommets supports the role of the Eustachian tube and otitis media (with effusion or acute) in the pathogenesis of chronic otitis media. The role of snoring, adenoidectomy and tonsillectomy is unclear. Associations suggested by previous studies (sex, socioeconomic group, parental smoking, maternal education, childcare, crowding and siblings) were not found to be significant predictors in this analysis.

The birth experience and subsequent maternal caregiving attitudes and behavior: a birth cohort study

Optimal maternal caregiving is critical for children's healthy development, yet quality of maternal caregiving may be influenced by a negative birth experience. We examined whether the birth experience was associated with maternal caregiving attitudes and behavior throughout the first year. We conducted secondary analysis of the Avon Longitudinal Study of Parents and Children birth cohort on perinatal data. The birth experience was assessed using self-report data on level of support in labor. Maternal caregiving variables were self-report maternal attitudes at one and eight postnatal months, and observed maternal behavior at 12 postnatal months. Data were analyzed using multivariable logistic regression models adjusting for critical covariates at one (N = 4389), eight (N = 4580), and 12 (N = 842) postnatal months. Feeling supported in labor was associated with a report of "immediately falling in love" with one's baby after birth, surveyed at 1 month (adjusted OR 1.41 [95% CI 1.20-1.65]), and with more positive parenting scores at 8 months (adjusted OR 1.56 [95% CI 1.36-1.79]), but not with more positive observed maternal behavior at 12 months. Additional risk factors were identified. Our findings suggest that we may be able to modify the risk of poor postnatal maternal caregiving by supporting women in labor and facilitating a positive birth experience.

Attenuated cortisol reactivity to psychosocial stress is associated with greater visual dependency in postural control

Despite known anatomical links between the hypothalamic-pituitary-adrenal (HPA) axis and the vestibular system, there are no studies on the relationship between postural control and HPA axis function. Visual dependence in postural control, often measured by increased postural sway on exposure to visual motion, is an indication of altered visual-vestibular integration with greater weighting towards visual cues for balance. Visual dependence is more common in older age and a range of vestibular and non-vestibular health conditions. The relationship between visual dependence in postural control was investigated in relation to cortisol reactivity to psychosocial stress (using the Trier Social Stress Test for groups: TSST-G), as an index of HPA axis function, in healthy young females. In those who exhibited a cortisol response (>2 nmol/l), a negative relationship between stress-induced cortisol reactivity and visual dependence in postural control was observed, since those with the largest cortisol response showed less visual motion induced postural sway (measured by force platform). This finding in healthy females indicates that subtle non-clinical differences in vestibular function are associated with dysregulated HPA axis activity as indicated by lower cortisol reactivity to psychosocial stress. It adds to the growing body of evidence linking blunted cortisol reactivity to stress to poor homeostatic regulation and potential negative health and behavioural outcomes.

ASD and schizophrenia show distinct developmental profiles in common genetic overlap with population-based social communication difficulties

Difficulties in social communication are part of the phenotypic overlap between autism spectrum disorders (ASD) and schizophrenia. Both conditions follow, however, distinct developmental patterns. Symptoms of ASD typically occur during early childhood, whereas most symptoms characteristic of schizophrenia do not appear before early adulthood. We investigated whether overlap in common genetic influences between these clinical conditions and impairments in social communication depends on the developmental stage of the assessed trait. Social communication difficulties were measured in typically-developing youth (Avon Longitudinal Study of Parents and Children, N⩽5553, longitudinal assessments at 8, 11, 14 and 17 years) using the Social Communication Disorder Checklist. Data on clinical ASD (PGC-ASD: 5305 cases, 5305 pseudo-controls; iPSYCH-ASD: 7783 cases, 11 359 controls) and schizophrenia (PGC-SCZ2: 34 241 cases, 45 604 controls, 1235 trios) were either obtained through the Psychiatric Genomics Consortium (PGC) or the Danish iPSYCH project. Overlap in genetic influences between ASD and social communication difficulties during development decreased with age, both in the PGC-ASD and the iPSYCH-ASD sample. Genetic overlap between schizophrenia and social communication difficulties, by contrast, persisted across age, as observed within two independent PGC-SCZ2 subsamples, and showed an increase in magnitude for traits assessed during later adolescence. ASD- and schizophrenia-related polygenic effects were unrelated to each other and changes in trait-disorder links reflect the heterogeneity of genetic factors influencing social communication difficulties during childhood versus later adolescence. Thus, both clinical ASD and schizophrenia share some genetic influences with impairments in social communication, but reveal distinct developmental profiles in their genetic links, consistent with the onset of clinical symptoms.

Childbirth and symptoms of postpartum depression and anxiety: a prospective birth cohort study

We investigated associations between aspects of childbirth and elevated postpartum symptoms of depression and anxiety. We employed secondary analysis of perinatal data (N = 4657-4946) from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Multivariable logistic regression models (adjusted for covariates) examined predictors of elevated symptoms of postpartum depression and anxiety. Predictors included the following: type of delivery (normal physiological vs. interventive non-physiological), immediate postpartum complications, and maternal perception of the recent birth experience. The Edinburgh Postnatal Depression Scale assessed elevated symptoms of depression (score ≥ 13), and the Crown-Crisp Experiential Index assessed elevated symptoms of anxiety (score ≥ 9) at 2 and 8 months after delivery. A more negative perception of the recent birth experience was associated with elevated symptoms of anxiety at 2 months [odds ratio (OR) 1.52, 95 % confidence interval (CI) 1.25-1.85] and 8 months (OR 1.30, 95 % CI 1.06-1.60) postpartum but was not associated with elevated symptoms of depression at either time point. Type of delivery (physiological vs. non-physiological) and immediate postpartum complications were not associated with elevated symptoms of depression or anxiety. Our findings suggest that improving women's childbirth experience may decrease the likelihood of postpartum anxiety, but not postpartum depression.

Girl or boy? Prenatal lead, cadmium and mercury exposure and the secondary sex ratio in the ALSPAC study

The aim of this study was to evaluate the effect of prenatal exposure to lead, cadmium and mercury levels on the secondary sex ratio. Whole blood samples were collected from pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) study at a median gestational age of 11 weeks and were analyzed for lead, cadmium and mercury. Regression analysis was used to identify associations between maternal lead, cadmium and mercury levels and the secondary sex ratio with adjustment for confounders. There was no evidence for associations between maternal lead, cadmium or mercury levels and the secondary sex ratio in this sample. It appears unlikely that alterations in the secondary sex ratio are influenced by exposure to heavy metals, but further work should be done in large cohorts in other countries to confirm these findings.

Adverse effects of maternal lead levels on birth outcomes in the ALSPAC study: a prospective birth cohort study

Objective

To study the associations of prenatal blood lead levels (B-Pb) with pregnancy outcomes in a large cohort of mother–child pairs in the UK.

Design

Prospective birth cohort study.

Setting

Avon area of Bristol, UK.

Population

Pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC).

Methods

Whole blood samples were collected and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Data collected on the infants included anthropometric variables and gestational age at delivery. Linear regression models for continuous outcomes and logistic regression models for categorical outcomes were adjusted for covariates including maternal height, smoking, parity, sex of the baby and gestational age.

Main outcome measures

Birthweight, head circumference and crown–heel length, preterm delivery and low birthweight.

Results

The mean blood lead level (B-Pb) was 3.67 ± 1.47 μg/dl. B-Pb ≥ 5 μg/dl significantly increased the risk of preterm delivery (adjusted odds ratio [OR] 2.00 95% confidence interval [95% CI] 1.35–3.00) but not of having a low birthweight baby (adjusted OR 1.37, 95% CI 0.86–2.18) in multivariable binary logistic models. Increasing B-Pb was significantly associated with reductions in birth weight (β −13.23, 95% CI −23.75 to −2.70), head circumference (β −0.04, 95% CI −0.07 to −0.06) and crown–heel length (β −0.05, 95% CI −0.10 to −0.00) in multivariable linear regression models.

Conclusions

There was evidence for adverse effects of maternal B-Pb on the incidence of preterm delivery, birthweight, head circumference and crown–heel length, but not on the incidence of low birthweight, in this group of women.

Parent-infant vocalisations at 12 months predict psychopathology at 7 years

This study investigated the utility of adult and infant vocalisation in the prediction of child psychopathology. Families were sampled from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Vocalisation patterns were obtained from 180 videos (60 cases and 120 randomly selected sex-matched controls) of parent-infant interactions when infants were one year old. Cases were infants who had been subsequently diagnosed aged seven years, with at least one psychiatric diagnostic categorisation using the Development and Wellbeing Assessment. Psychopathologies included in the case group were disruptive behaviour disorders, oppositional-conduct disorders, Attention Deficit Hyperactivity Disorder, pervasive development disorder, and emotional disorders. Associations between infant and parent vocalisations and later psychiatric diagnoses were investigated. Low frequencies of maternal vocalisation predicted later development of infant psychopathology. A reduction of five vocalisations per minute predicted a 44% (95%CI: 11-94%; p-value=0.006) increase in the odds of an infant being a case. No association was observed between infant vocalisations and overall case status. In sum, altered vocalisation frequency in mother-infant interactions at one year is a potential risk marker for later diagnosis of a range of child psychopathologies.

Predictors of diagnosis of child psychiatric disorder in adult-infant social-communicative interaction at 12 months

To establish which social interactive behaviours predict later psychiatric diagnosis, we examined 180 videos of a parent-infant interaction when children were aged one year, from within the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort. Sixty of the videos involved infants who were later diagnosed with a psychiatric disorder at seven years, and 120 were a randomly selected sex-matched control group. Interactive behaviours for both the caregiver and the one year old infant were coded from the videos according to eight holistic categories of interpersonal engagement: Well-being, Contingent Responsiveness, Cooperativeness, Involvement, Activity, Playfulness, Fussiness, and Speech. Lower levels of adult activity and speech in interaction at one year significantly predicted overall diagnosis of child psychiatric disorder.

Can psychopathology at age 7 be predicted from clinical observation at one year? Evidence from the ALSPAC cohort

One of the challenges of developmental psychopathology is to determine whether identifiable pathways to developmental disorders exist in the first months or years of life. Early identification of such disorders poses a similar challenge for clinical services. Using data from a large contemporary birth cohort, we examined whether psychopathology at age seven can be predicted from clinician observation at one year. Two groups of clinical raters observed videos of caregiver-infant interaction. Neither group of raters could reliably identify any precursors of later development of psychopathology in the one-year-old infants in this setting.

Association of socioeconomic position with maternal pregnancy and infant health outcomes in birth cohort studies from Brazil and the UK

BACKGROUND

Socioeconomic inequalities in health outcomes are dynamic and vary over time. Differences between countries can provide useful insights into the causes of health inequalities. The study aims to compare the associations between two measures of socioeconomic position (SEP)-maternal education and family income-and maternal and infant health outcomes between ALSPAC and Pelotas cohorts.

METHODS

Birth cohort studies were started in Avon, UK, in 1991 (ALSPAC) and in the city of Pelotas, Brazil, in 1982, 1993 and 2004. Maternal outcomes included smoking during pregnancy, caesarean section and delivery not attended by a doctor. Infant outcomes were preterm birth, intra-uterine growth restriction (IUGR) and breast feeding for <3 months. The relative index of inequality was used for each measure of SEP so that results were comparable between cohorts.

RESULTS

An inverse association (higher prevalence among the poorest and less educated) was observed for almost all outcomes, with the exception of caesarean sections where a positive association was found. Stronger income-related inequalities for smoking and education-related inequalities for breast feeding were found in the ALSPAC study. However, greater inequalities in caesarean section and education-related inequalities in preterm birth were observed in the Pelotas cohorts.

CONCLUSIONS

Mothers and infants have more adverse health outcomes if they are from poorer and less well-educated socioeconomic backgrounds in both Brazil and the UK. However, our findings demonstrate the dynamic nature of the association between SEP and health outcomes. Examining differential socioeconomic patterning of maternal and infant health outcomes might help understanding of mechanisms underlying such inequalities.

A qualitative analysis of lay beliefs about the aetiology and prevalence of autistic spectrum disorders

INTRODUCTION

There has been a dramatic increase in the prevalence of autistic spectrum disorders (ASD) in the last 20 years. The reasons for this are disputed. The consensus among epidemiologists and other experts is that greater case load is due to changes in diagnostic practice rather than reflecting changing aetiological factors leading to a true increase in incidence. We set out to examine lay views concerning the aetiology and prevalence of ASD and whether they conflict with or support this consensus position.

METHODS

Over 100 unsolicited communications (letters e-mail and several telephone calls) were received by a UK epidemiological study of ASD. We carried out a qualitative analysis of all correspondence in order to examine spontaneously expressed lay beliefs about the prevalence and aetiology of ASD.

RESULTS

The majority of correspondents suggested theories about environmental causes of ASD. This study demonstrates the strength of lay belief that the true incidence of autism is rising, and this is due to risks from modern technologies and changing lifestyles.

CONCLUSION

This study based on unsolicited data highlights the contrast between lay explanations of increasing prevalence and the consensus opinion of medical experts. It also demonstrates how many people in direct contact with ASD have important information to share.

The early stool patterns of young children with autistic spectrum disorder

AIM

To investigate whether children with autistic spectrum disorder (ASD) have bowel symptoms consistent with underlying enterocolitis.

METHODS

Information on children's stool patterns and gut symptoms collected by questionnaire at 4 weeks and at 6, 18, 30 and 42 months of age were available for 12,984 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). Data on the 78 children identified by local health and/or education systems to have special educational provision for ASD were compared with the 12,906 remaining children in the cohort.

RESULTS

Comparison of the ASD and control group during the first 3.5 years of life showed no major differences in stool colour or consistency, or in frequency of diarrhoea, constipation, bloody stools or abdominal pain. The ASD children had similar stool frequency up to 18 months, but there was a trend for ASD children to pass more stools at 30 months (OR 3.73, 95% CI 1.11 to 12.6; p = 0.004) and at 42 months (OR 6.46, 95% CI 1.83 to 22.7; p<0.001), although only three children passed more than 4 stools/day. Repeating the analysis on only those cases diagnosed as having classical childhood autism resulted in very similar findings.

CONCLUSIONS

During the first 42 months of life, ASD children had a stool pattern that was very similar to that of other children, apart from a slight increase in stool frequency at 30 and 42 months. There were no symptoms to support the hypothesis that ASD children had enterocolitis.

The variation in stool patterns from 1 to 42 months: a population-based observational study

OBJECTIVE

To document the normal stool patterns of young children.

DESIGN

Prospective population-based longitudinal study.

SETTING

Avon Longitudinal Study of Parents and Children (ALSPAC).

SUBJECTS

12,984 children, whose parents completed questionnaires at 4 weeks, 6, 18, 30 and 42 months on their frequency of bowel movements and the consistency and colour of their stools.

RESULTS

Stool frequency declined from a mean of 3.0 times/day (3rd centile 0.6, 97th centile 5.9) at 4 weeks to 1.3 times/day (0.6, 2.7) at 42 months. Stool consistency was soft in most babies with nearly half passing liquid or curdy stool at 4 weeks. 14% of babies usually passed a hard stool at 4 weeks, rising to 30% at 42 months. Stool colour was commonly yellow at 4 weeks and had changed to brown by 6 months. Black stools were extremely unusual at all ages.

CONCLUSIONS

These data on the changes with age in the stool patterns of young children will be useful for clinicians.

Factor V Leiden is associated with pre-eclampsia but not with fetal growth restriction: a genetic association study and meta-analysis

BACKGROUND

Adverse pregnancy outcomes have been related to environmental and/or genetic factors. Of interest are genes associated with the clotting system as any perturbation in the balance of thrombotic and thrombolytic cascades could affect the placental circulation and hence the viability of the developing fetus. Several previous reports using relatively small numbers of cases and controls have suggested that there is a relationship between poor pregnancy outcomes and two polymorphisms, one in the factor V gene, the 1691G to A change (rs6025) located on chromosome 1q23 (factor V Leiden, FVL), and the other in the prothrombin gene, 20210G to A change (rs1799963) on chromosome 11p11-q12 (PT). These results, however, are conflicting.

METHODS

We genotyped 6755 mother/infant pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC) to determine whether maternal or fetal FVL or PT, either alone or in combination, are associated with fetal growth restriction (FGR) or pre-eclampsia (PE). We also added the present results to previous cohort studies using meta-analysis.

RESULTS

Smoking, primiparity and lower body mass index (BMI) were all associated with FGR, but neither maternal nor fetal FVL or PT, singly or in combination, were associated with FGR in the ALSPAC cohort. Meta-analysis confirmed the lack of association between maternal FVL and FGR with a pooled odds ratio (OR) of 1.15 [95% confidence interval (CI) 0.95-1.39]. High BMI, primiparity, diabetes and chronic hypertension were all associated with pre-eclampsia. Combining ALSPAC results with previous studies in ameta-analysis indicated that maternal FVL is significantly associated with pre-eclampsia, with a pooled OR of 1.49 (95% CI 1.13-1.96).

CONCLUSION

Neither maternal nor fetal FVL or PT, singly or in combination, are associated with FGR; this contradicts previous case-control studies and meta-analyses based on these studies. In a meta-analysis of all published cohort studies to date, maternal FVL appears to increase the risk of pre-eclampsia by almost 50%. This result is robust, homogeneous and does not appear to be affected by publication bias.

Chronic morbidity in women, namely in pregnancy. (Comparative study between West, Central and East European centres)

18 chronic diseases were investigated in a population of 13,115 women living in six settings of West- (Avon UK, the Isle of Man), Central- (the Czech Republic and the Slovak Republic) and East-Europe (the Ukraine and Russia), that collaborate in the European Longitudinal Study of Pregnancy and Childhood (ELSPAC project). In prenatal questionnaires filled in after the first half of pregnancy, women reported 25,795 chronic diseases they ever suffered, out of them 11,188 having in present pregnancies. In the whole sample, lifelong prevalence was 11,2%, and prevalence in pregnancy 4,8% which means that 43,4% of all chronic diseases recurred in pregnancy. Up to mean age of 255 years in the whole sample, 39,6% women reported ever having indigestion, 29% back pains, 22,6% migraine, about 16% haemorrhoids, hay fever and eczema, about 10% varicose veins, anorexia nervosa, heavy depression and kidney diseases, over 5% rheumatism and 4% asthma. Less prevalent were infections of pelvic organs, febrile convulsions, joint inflammations, stomach ulcers, psoriasis and epilepsy. Lifetime prevalence of chronic diseases and their prevalence in pregnancy were the highest in the western zone and decreased eastwards, but recurrence grew in the opposite direction, being the highest in the eastern zone. The variation of each morbidity indicator is followed in all diseases between geographical zones as well as between individual study centres.

Relationship between aeroallergen and food allergen sensitization in childhood

BACKGROUND

Previous studies measuring the prevalence of allergen sensitization have been relatively small and used small numbers of allergens. To effectively evaluate children with atopic disease, we need an accurate knowledge of which allergens are important.

OBJECTIVE

To measure the prevalence of sensitization within a large unselected birth cohort, to examine the associations between sensitization to different allergens and determine whether atopy can be defined by a small panel of allergens.

METHODS

The Avon Longitudinal Study of Parents and Children is a population-based birth cohort of 13,638 singletons surviving to 4 weeks of age. The cohort was skin tested at 7 years of age to house dust mite (Dermatophagoides pteronyssinus), grass pollens, cat, peanuts, mixed tree nuts and egg and one of three other panels: animal danders, foods or aeroallergens. Sensitization was defined as a weal diameter of > or =3 mm. The strength of associations between sensitization to different allergens was tested by calculating the odds ratio adjusted for sensitization to D. pteronyssinus and grass pollen and gender.

RESULTS

Valid data were obtained from 6412 singletons. Sensitization was most common to aeroallergens: grass pollens (8.5%), D. pteronyssinus (7.8%), cat (4.9%), D. farinae (3.6%), dog (2.7%), horse (1.4%), rabbit (1.4%). Of the foods tested, the most common sensitization was to peanut (1.4%) and mixed tree nuts (1.0%). More than 95% of subjects with sensitization to any of the 29 allergens tested were sensitized to one of grass, D. pteronyssinus or cat allergen. There were strong associations of multiple sensitizations both within and between different allergen classes (pollens, animals, foods, peanut and tree nuts).

CONCLUSIONS

Seven-year-old children in the UK are primarily sensitized to aeroallergens, but also to peanuts and tree nuts. There are strong associations between sensitization within allergen groups as well as between allergen groups. Further studies are required to observe whether similar associations are seen with clinical allergy to these allergens.

Nocturnal enuresis: a survey of parental coping strategies at 7 1/2 years

BACKGROUND

Childhood nocturnal enuresis is a potentially distressing experience. Parents have been found to adopt many approaches designed to help their child become dry at night. This study sought to understand, through a large cohort of children at 7 1/2 years of age, the strategies parents adopt, both during the child's development and currently, to help their child overcome bed-wetting.

METHODS

A longitudinal cohort of 13,971 children with expected date of delivery between April 1991-December 1992, in the County of Avon (Bristol) formed the population study group. At 7 1/2 years parents were asked, as part of a regular self-report questionnaire, what methods they had tried or were currently using to help their child stop bed-wetting. Eleven options were supplied.

RESULTS

Of 8269 parents responding to the questionnaire, 3376 (40.8%) indicated they had tried at least one of 11 strategies, with restricting night-time fluids and lifting being the predominant methods employed. Amongst strategies employed in the past, lifting and showing displeasure were used significantly more by parents of children with nocturnal enuresis than by those with children dry at 7 1/2 years. However, a greater proportion of parents of dry children encouraged their offspring to toilet more regularly in the daytime than parents of those with nocturnal enuresis or infrequent wetting. In terms of treatment interventions, the enuresis alarm had been employed with 19.2% and medication with 13.1% of those with nocturnal enuresis, although only 31.9% of those with nocturnal enuresis had seen a health worker. The results are discussed in relation to preventative and clinical implications.

Early experiences and their relationship to maternal eating disorder symptoms, both lifetime and during pregnancy

BACKGROUND

There is some evidence that early sexual abuse is an aetiological factor for eating disorder. However, there is sparse information from large-scale, non-clinical studies.

AIMS

This study was designed to explore which early experiences, recalled during pregnancy, were associated with both lifetime and antenatal eating disorder symptoms in a community sample.

METHOD

Univariate and multivariate analyses were conducted of data from questionnaires administered during pregnancy to a community sample of pregnant women.

RESULTS

Recall of parental mental health problems and of early unwanted sexual experiences were independently associated with both lifetime eating problems, laxative use and vomiting during pregnancy, and marked concern during pregnancy over shape and weight.

CONCLUSIONS

There are public health implications for these results. Eating disorders in mothers represent a risk for child development. It may be important to enquire during pregnancy about a history of eating problems and to provide the opportunity for early experiences to be discussed.

Prevalence of latex allergy in the community at age 7 years

BACKGROUND

Latex allergy has been highlighted as a problem in children during the last decade based on a number of case series of children with particular problems such as spina bifida. The actual prevalence of latex allergy in the general United Kingdom population is unclear.

OBJECTIVE

To estimate the prevalence of childhood latex allergy in the general population.

METHODS

The Avon Longitudinal Study of Parents and Children is a geographically based cohort that has been prospectively followed since birth. The children were invited for skin prick testing at 7 years of age.

RESULTS

Four subjects out of 1877 tested were sensitized to latex. None had a history of clinical reactions to latex.

CONCLUSION

This study suggests that the prevalence of latex sensitization and clinical latex allergy in the general childhood population are very low, 0.2% (95% confidence interval 0.1-0.6%) and 0.0% (0-0.2%), respectively.

Frequent use of chemical household products is associated with persistent wheezing in pre-school age children

BACKGROUND

In the UK and other developed countries the prevalence of asthma symptoms has increased in recent years. This is likely to be the result of increased exposure to environmental factors. A study was undertaken to investigate the association between maternal use of chemical based products in the prenatal period and patterns of wheeze in early childhood.

METHODS

In the population based Avon Longitudinal Study of Parents and Children (ALSPAC), the frequency of use of 11 chemical based domestic products was determined from questionnaires completed by women during pregnancy and a total chemical burden (TCB) score was derived. Four mutually exclusive wheezing patterns were defined for the period from birth to 42 months based on parental questionnaire responses (never wheezed, transient early wheeze, persistent wheeze, and late onset wheeze). Multinomial logistic regression models were used to assess the relationship between these wheezing outcomes and TCB exposure while accounting for numerous potential confounding variables. Complete data for analysis was available for 7019 of 13, 971 (50%) children.

RESULTS

The mean (SD) TCB score was 9.4 (4.1), range 0-30. Increased use of domestic chemical based products was associated with persistent wheezing during early childhood (adjusted odds ratio (OR) per unit increase of TCB 1.06 (95% confidence interval (CI) 1.03 to 1.09)) but not with transient early wheeze or late onset wheeze. Children whose mothers had high TCB scores (>90th centile) were more than twice as likely to wheeze persistently throughout early childhood than children whose mothers had a low TCB score (<10th centile) (adjusted OR 2.3 (95% CI 1.2 to 4.4)).

CONCLUSION

These findings suggest that frequent use of chemical based products in the prenatal period is associated with persistent wheezing in young children. Follow up of this cohort is underway to determine whether TCB is associated with wheezing, asthma, and atopy at later stages in childhood.

Strategies to prevent eclampsia in a developing country: I. Reorganization of maternity services

OBJECTIVE

To determine whether changes in primary and secondary care service delivery could prevent antenatal eclampsia.

METHOD

One intervention (St. Catherine) and two control (St. Ann, Manchester) parishes were chosen. The health system in St. Catherine was restructured. Primary antenatal clinics had clear instructions for referring patients to a high-risk antenatal clinic or to hospital. Guidelines were provided to high-risk clinics and the antenatal ward for appropriate treatment of hypertension and preeclampsia when induction of labor should occur. Antenatal eclampsia incidence was monitored before and during the intervention and compared with control parishes (no intervention). Each eclampsia case was investigated to identify inadequacies in the system.

RESULTS

The process resulted in better identification of women at risk. Antenatal eclampsia incidence dropped dramatically as care improved. Compared with control areas, by completion of the study, the rate was significantly lower than at the start: OR 0.19 (95% CI: 0.13-0.27; p<0.001 trend). Antenatal admissions for hypertensive disorders declined significantly, and the number of bed days halved.

CONCLUSION

Reorganization of maternal care can have major public health benefits and cost savings; however, women need to be alerted to recognise and act upon signs of impending eclampsia.

Strategies to prevent eclampsia in a developing country: II. Use of a maternal pictorial card

OBJECTIVE

To assess the efficacy and acceptability of a patient-held pictorial card aimed at raising awareness and appropriate health seeking behavior in response to prodromal symptoms of imminent eclampsia.

METHOD

Pictorial cards (and posters) were issued to antenatal clinics and used to focus instruction and advice to pregnant women. Mothers were surveyed before and after the cards were introduced to assess maternal likelihood of seeking care if edema was seen, and of attending hospital if so advised. We monitored the eclampsia rate. Health workers were interviewed 6 months after cards and posters were issued to determine the acceptability of using the cards as part of routine antenatal care.

RESULTS

The card was seen as widely acceptable by health professionals, and increased their own awareness of the prodromal symptoms of eclampsia and their discussion of these symptoms with antenatal mothers. Mothers' awareness and response to symptoms improved significantly and there was a marked drop in eclampsia incidence. Suggested improvements to the card were made by mothers and health workers.

CONCLUSION

The cost of providing a card for every pregnant mother is likely to be offset by health service delivery savings.

Association of parental eczema, hayfever, and asthma with atopic dermatitis in infancy: birth cohort study

OBJECTIVE

To evaluate the association of parental history of atopic disease with childhood atopic dermatitis, and to examine the relative strength of associations with maternal and paternal disease.

DESIGN

Mothers were recruited to the Avon longitudinal study of parents and children (ALSPAC) from the eighth week of pregnancy. Before parturition, both parents were asked, separately, to report their lifetime history of eczema, asthma, and hayfever. Parents reported symptoms of atopic dermatitis in their children at ages 6, 18, 30, and 42 months.

RESULTS

Of 8530 children with complete information on rash at ages 6, 18, 30, and 42 months, 7969 had complete information on maternal atopic disease and 5658 on maternal and paternal atopic disease. There was a strong association between parental eczema and childhood atopic dermatitis: odds ratio 1.69 (95% confidence interval, 1.47 to 1.95) for maternal eczema only, 1.74 (1.44 to 2.09) for paternal eczema only, and 2.72 (2.09 to 3.53) for eczema in both parents. Associations with parental asthma or hayfever were attenuated after controlling for parental eczema. There was no evidence that associations with maternal atopy were stronger than with paternal.

CONCLUSIONS

Associations between parents' atopic disease and the risk of atopic dermatitis in offspring vary according to the type of atopic disease in the parents, but not according to parental sex. These results are at variance with previous studies reporting stronger associations with maternal than paternal atopy, and suggest that there is no "parent-of-origin" effect in atopic dermatitis. Parental eczema may be a better marker than parental asthma/hayfever in predisposing to childhood eczema.

Maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation in a cohort of British infants

OBJECTIVE

To investigate the relation between maternal fish intake in late pregnancy and the frequency of low birth weight and intrauterine growth retardation (IUGR).

PARTICIPANTS

11 585 pregnant women in south west England.

METHODS

Information on fish intake was obtained from a food frequency questionnaire sent to the women at 32 weeks' gestation, and used to calculate n-3 fatty acid (n-3FA) intake from fish. IUGR was defined as a birth weight for gestational age and sex below the 10th centile. Confounding variables considered included maternal age, height, weight, education, parity, smoking and drinking in pregnancy, and whether the mother was living with a partner. Only singleton, liveborn infants were included.

MAIN RESULTS

Mean daily intakes of fish and n-3FAs were 32.8 g and 0.147 g respectively. In unadjusted analyses there were positive associations between mean birth weight and fish intake or n-3FA intake, but these disappeared on adjustment for potential confounders. The frequency of IUGR decreased with increasing fish intake-the OR (95%CI) of IUGR in those eating no fish was 1.85 (1.44 to 2.38) compared with those in the highest fish intake group. On adjustment this relation was attenuated (adjusted OR 1.37 (1.02 to 1.84)), but the decline in the frequency of IUGR with increasing fish intake remained statistically significant. No relation was observed between mean gestation and fish or n-3FA intake.

CONCLUSIONS

These results lend some support to the hypothesis that raising fish or n3-FA intake during pregnancy may increase fetal growth rate. However, they provide no evidence that increasing fish consumption is associated with an increase in mean gestation.

Medication use during pregnancy: data from the Avon Longitudinal Study of Parents and Children

OBJECTIVE

To present data on the self-reported use of all types of medicinal products collected during pregnancy in a large cohort in southwest England.

METHODS

Pregnant women with a delivery date during 1991-1992 and forming part of the prospective, population-based Avon Longitudinal Study of Parents and Children (ALSPAC) were sent up to four self-completion postal questionnaires during pregnancy. Text data collected from the questions on drug usage were coded using an ALSPAC drug dictionary based on the World Health Organization Drug Dictionary.

RESULTS

At least one antenatal self-completion questionnaire was completed for 14,119 pregnancies, and 11,545 women completed all four. The data included prescription, over-the-counter, herbal and homeopathic products as well as iron, vitamins and other supplements. Only 7.6% did not report use of any medicinal product throughout their entire pregnancy. The remaining 92.4% used at least one product at some stage. After exclusion of iron, folate, vitamins, supplements, herbal and homeopathic products and skin emollients, 83% of those completing all questionnaires had used conventional therapeutic drugs. Analgesics were reported by approximately one-third of women at each stage during pregnancy, and paracetamol was the most frequently reported substance. Iron preparations were reported by 33% of the full cohort, at some stage, and folate by 21.9%. Use of anti-anaemic products increased during pregnancy with the greatest incidence at 32 weeks. Other vitamins and supplements were taken by 17.4% at some stage. Use of vitamins decreased throughout pregnancy from 9.6% in early pregnancy to 5% at 32 weeks. Antacids were reported by 23% at 32 weeks. The reported incidence of antibiotic use decreased slightly during pregnancy from 8% early on to 5.8% at 32 weeks; amoxicillin was the most frequently reported antibacterial.

CONCLUSION

Use of medicinal products was high during pregnancy in the ALSPAC cohort. This finding is consistent with data from recent publications.

A prospective study of the prevalence and incidence of atopic dermatitis in children aged 0-42 months

BACKGROUND

There is strong evidence that the incidence and prevalence of atopic diseases is increasing. However, estimates of the prevalence of atopic dermatitis (AD) have varied greatly in the U.K. and most parts of the developed world.

OBJECTIVES

The aim of the study was to estimate the prevalence and incidence of AD between the ages of 0 and 42 months in children born in the 1990s in a defined population in the U.K.

DESIGN

We used data from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), a large population-based study in the U.K. that enrolled all pregnant mothers who were resident in Avon and had their delivery date falling between 1 April 1991 and 31 December 1992. Since then ALSPAC has collected a wide range of data from the newborns and their parents. Data reported here were collected at 6, 18, 30 and 42 months using parental reports in a postal questionnaire. Of the 14 009 children originally enrolled 8530 provided information on AD in each of the four follow-up questionnaires. We defined AD as a report of rash in at least two of the four questionnaires. Incidence risk was defined as the percentage of new cases of AD between follow-up questionnaires, out of the total number of children whose parents had not reported that they had AD by the time of the previous follow-up.

RESULTS

Period prevalence of 21.0%, 25.6%, 23.2% and 19.9% were observed at ages 0-6, 6-18, 18-30 and 30-42 months, respectively. The corresponding incidence risks were 21.0%, 11.2% and 3.8%, at 0-6, 6-18 and 18-30 months, respectively. There were no gender differences in either the incidence or prevalence of the disease.

CONCLUSIONS

Results from this large, prospective study are consistent with recent reports of increased incidence and prevalence of AD. Health planners can use our estimates of incidence and prevalence to project the number of children likely to suffer from AD during infancy and early childhood, and thus to determine the human and financial resources required.

Paracetamol use in pregnancy and wheezing in early childhood

BACKGROUND

We recently reported links between frequent paracetamol (acetaminophen) use and wheezing and asthma in adults and children, but data are lacking on possible effects of prenatal exposure on wheezing in early childhood.

METHODS

In the population based Avon Longitudinal Study of Parents and Children (ALSPAC) women were asked twice during pregnancy (at 18-20 weeks and 32 weeks) about their usage of paracetamol and aspirin. Six months after birth, and at yearly intervals thereafter, mothers were asked about wheezing and eczema symptoms in their child. The effects of paracetamol and aspirin use in pregnancy on the risk in the offspring of wheezing at 30-42 months (n=9,400) and eczema at 18-30 months (n=10,216) and on their risk of different wheezing patterns (defined by presence or absence of wheezing at <6 months and at 30-42 months) were examined.

RESULTS

Paracetamol was taken frequently (most days/daily) by only 1% of women. After controlling for potential confounders, frequent paracetamol use in late pregnancy (20-32 weeks), but not in early pregnancy (<18-20 weeks), was associated with an increased risk of wheezing in the offspring at 30-42 months (adjusted odds ratio (OR) compared with no use 2.10 (95% CI 1.30 to 3.41); p=0.003), particularly if wheezing started before 6 months (OR 2.34 (95% CI 1.24 to 4.40); p=0.008). Assuming a causal relation, only about 1% of wheezing at 30-42 months was attributable to this exposure. Frequent paracetamol use in pregnancy was not associated with an increased risk of eczema. Frequent aspirin use in pregnancy was associated with an increased risk of wheezing only at <6 months.

CONCLUSIONS

Frequent use of paracetamol in late pregnancy may increase the risk of wheezing in the offspring, although such an effect could explain only about 1% of the population prevalence of wheezing in early childhood.

Reduced birth weight in boys with hypospadias: an index of androgen dysfunction?

Anthropometric birth measurements analysed for 51 boys with hypospadias identified in a prospective cohort study showed significant reductions in mean values for birth weight, length, and head circumference compared with controls. The absence of the usual sex dimorphism for these variables suggests that the results represent a marker of fetal androgen dysfunction in this subgroup of infants.

Factors associated with different hygiene practices in the homes of 15 month old infants

BACKGROUND

Improved hygiene in Westernised regions of the world may be partly responsible for the increased prevalence of diseases of the immune system, such as asthma and atopy. There is a paucity of data on cleanliness norms in young children in the UK and there has been no attempt to identify factors that influence the adoption of particular hygiene practices in the home.

AIMS

To examine levels of hygiene in a contemporary cohort of children and identify social and lifestyle factors influencing hygiene practices in the home.

METHODS

The sample under study are participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental self completion questionnaires provided data on hygiene levels in children at 15 months of age, and a hygiene score was derived from these responses. Multivariable logistic regression models investigated associations between high hygiene scores (top quintile) and a number of perinatal, maternal, social, and environmental factors.

RESULTS

Maternal smoking during pregnancy, low maternal educational achievement, and living in local authority housing were factors independently associated with high hygiene scores, as was increased use of chemical household products. High hygiene scores were inversely related to living in damp housing and attendance at day care. There were no gender or ethnic differences in hygiene score.

CONCLUSION

Important data on cleanliness norms for infants have been presented. The adoption of hygiene practices is influenced to some degree by social, lifestyle, and environmental factors-with higher hygiene scores occurring in more socially disadvantaged groups. Increased use of chemical household products in the more socially disadvantaged groups within ALSPAC has emerged as an important confounder in any study of hygiene and ill health.

Hygiene levels in a contemporary population cohort are associated with wheezing and atopic eczema in preschool infants

BACKGROUND

The hygiene hypothesis states that insufficient exposure to certain infectious agents during childhood increases the risk of developing asthma and atopic diseases. Improvements in hygiene levels may be partly responsible for this decline in exposure.

AIMS

To assess whether hygiene levels in infancy are associated with wheeze and/or atopic eczema, independent of a number of possible confounding factors.

METHODS

Data were gathered from the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental self completion questionnaires provided symptom data on infant wheeze and atopic eczema at 0-6 months and 30-42 months, respectively. A simple hygiene score was derived using questionnaire responses at 15 months, which ranged from least hygienic to most hygienic. Multivariable logistic regression models analysed the effect of hygiene scores on health outcomes, while adjusting for a number of important confounding variables.

RESULTS

Increasing hygiene scores were independently associated with wheezing (OR = 1.04; 95% CI: 1.00 to 1.08) and atopic eczema (OR = 1.04; 95% CI: 1.01 to 1.07) between 30 and 42 months, but not in the first six months. The odds ratio was higher for atopic eczema if the rash was reported to have become sore and oozy (OR = 1.09; 95% CI: 1.02 to 1.16).

CONCLUSIONS

High levels of hygiene at 15 months of age were independently associated with wheeze and atopic eczema reported between 30 and 42 months, and there was an increased risk for children with more severe eczema during this period. The importance of hygiene in public health should not be dismissed; however, the creation of a sterile environment through excessive cleanliness may potentially be harmful to the immune system.

Child maltreatment in the "children of the nineties" a longitudinal study of parental risk factors

OBJECTIVE

To identify and validate factors within the parental background affecting risk of child maltreatment.

METHOD

A nested case-control study based on the Avon Longitudinal Study of Parents and Children ("Children of the Nineties"), a cohort of children born in Avon in 1991 through 1992. Data on the childhood and psychiatric histories of the parents, along with other data on the social and family environments, have been collected through postal questionnaires from early antenatal booking onwards.

RESULTS

Out of 14,138 participating children, 162 have been identified as having been maltreated. Using logistic regression analysis, significant risk factors within the mothers' backgrounds were age < 20; lower educational achievement; history of sexual abuse; child guidance or psychiatry; absence of her father during childhood; and a previous history of psychiatric illness. Significant factors in the fathers' backgrounds were age < 20; lower educational achievement; having been in care during childhood; and a history of psychiatric illness. Significant factors on univariate, but not multivariate analysis included a parental history of childhood physical abuse; divorce or separation of the mother's parents; a maternal history of having been in care, or separated from her mother; parental alcohol or drug abuse; and a maternal history of depression.

CONCLUSIONS

This study, the first of its kind in the UK, supports the findings of others that parental age, educational achievement, and a history of psychiatric illness are of prime importance in an understanding of child maltreatment. With the exception of maternal sexual abuse, a history of abuse in childhood is not significant once adjusted for other background factors. The study suggests that psychodynamic models are inadequate to explain child maltreatment, and wider models incorporating other ecological domains are needed.

Cohort study of depressed mood during pregnancy and after childbirth

OBJECTIVE

To follow mothers' mood through pregnancy and after childbirth and compare reported symptoms of depression at each stage.

DESIGN

Longitudinal cohort study.

SETTING

Avon.

PARTICIPANTS

Pregnant women resident within Avon with an expected date of delivery between 1 April 1991 and 31 December 1992.

MAIN OUTCOME MEASURES

Symptom scores from the Edinburgh postnatal depression scale at 18 and 32 weeks of pregnancy and 8 weeks and 8 months postpartum. Proportion of women above a threshold indicating probable depressive disorder.

RESULTS

Depression scores were higher at 32 weeks of pregnancy than 8 weeks postpartum (difference in means 0.88, 95% confidence interval 0.79 to 0.97). There was no difference in the distribution of total scores or scores for individual items at the four time points. 1222 (13.5%) women scored above threshold for probable depression at 32 weeks of pregnancy, 821 (9.1%) at 8 weeks postpartum, and 147 (1.6%) throughout. More mothers moved above the threshold for depression between 18 weeks and 32 weeks of pregnancy than between 32 weeks of pregnancy and 8 weeks postpartum.

CONCLUSIONS

Symptoms of depression are not more common or severe after childbirth than during pregnancy. Research and clinical efforts need to be moved towards understanding, recognising, and treating antenatal depression.