Antiretroviral therapy during pregnancy and premature birth: analysis of Swiss data

Background There is an ongoing debate as to whether combined antiretroviral treatment (cART) during pregnancy is an independent risk factor for prematurity in HIV-1-infected women. Objective The aim of the study was to examine (1) crude effects of different ART regimens on prematurity, (2) the association between duration of cART and duration of pregnancy, and (3) the role of possibly confounding risk factors for prematurity. Method We analysed data from 1180 pregnancies prospectively collected by the Swiss Mother and Child HIV Cohort Study (MoCHiV) and the Swiss HIV Cohort Study (SHCS). Results Odds ratios for prematurity in women receiving mono/dual therapy and cART were 1.8 [95% confidence interval (CI) 0.85–3.6] and 2.5 (95% CI 1.4–4.3) compared with women not receiving ART during pregnancy (P=0.004). In a subgroup of 365 pregnancies with comprehensive information on maternal clinical, demographic and lifestyle characteristics, there was no indication that maternal viral load, age, ethnicity or history of injecting drug use affected prematurity rates associated with the use of cART. Duration of cART before delivery was also not associated with duration of pregnancy. Conclusion Our study indicates that confounding by maternal risk factors or duration of cART exposure is not a likely explanation for the effects of ART on prematurity in HIV-1-infected women.

Does pet ownership in infancy lead to asthma or allergy at school age? Pooled analysis of individual participant data from 11 European birth cohorts

Objective To examine the associations between pet keeping in early childhood and asthma and allergies in children aged 6–10 years. Design Pooled analysis of individual participant data of 11 prospective European birth cohorts that recruited a total of over 22,000 children in the 1990s. Exposure definition Ownership of only cats, dogs, birds, rodents, or cats/dogs combined during the first 2 years of life. Outcome definition Current asthma (primary outcome), allergic asthma, allergic rhinitis and allergic sensitization during 6–10 years of age. Data synthesis Three-step approach: (i) Common definition of outcome and exposure variables across cohorts; (ii) calculation of adjusted effect estimates for each cohort; (iii) pooling of effect estimates by using random effects meta-analysis models. Results We found no association between furry and feathered pet keeping early in life and asthma in school age. For example, the odds ratio for asthma comparing cat ownership with “no pets” (10 studies, 11489 participants) was 1.00 (95% confidence interval 0.78 to 1.28) (I2 = 9%; p = 0.36). The odds ratio for asthma comparing dog ownership with “no pets” (9 studies, 11433 participants) was 0.77 (0.58 to 1.03) (I2 = 0%, p = 0.89). Owning both cat(s) and dog(s) compared to “no pets” resulted in an odds ratio of 1.04 (0.59 to 1.84) (I2 = 33%, p = 0.18). Similarly, for allergic asthma and for allergic rhinitis we did not find associations regarding any type of pet ownership early in life. However, we found some evidence for an association between ownership of furry pets during the first 2 years of life and reduced likelihood of becoming sensitized to aero-allergens. Conclusions Pet ownership in early life did not appear to either increase or reduce the risk of asthma or allergic rhinitis symptoms in children aged 6–10. Advice from health care practitioners to avoid or to specifically acquire pets for primary prevention of asthma or allergic rhinitis in children should not be given.

A multinational case-control study on childhood brain tumours, anthropogenic factors, birth characteristics and prenatal exposures: A validation of interview data.

Little is known about the aetiology of childhood brain tumours. We investigated anthropometric factors (birth weight, length, maternal age), birth characteristics (e.g. vacuum extraction, preterm delivery, birth order) and exposures during pregnancy (e.g. maternal: smoking, working, dietary supplement intake) in relation to risk of brain tumour diagnosis among 7-19 year olds. The multinational case-control study in Denmark, Sweden, Norway and Switzerland (CEFALO) included interviews with 352 (participation rate=83.2%) eligible cases and 646 (71.1%) population-based controls. Interview data were complemented with data from birth registries and validated by assessing agreement (Cohen's Kappa). We used conditional logistic regression models matched on age, sex and geographical region (adjusted for maternal age and parental education) to explore associations between birth factors and childhood brain tumour risk. Agreement between interview and birth registry data ranged from moderate (Kappa=0.54; worked during pregnancy) to almost perfect (Kappa=0.98; birth weight). Neither anthropogenic factors nor birth characteristics were associated with childhood brain tumour risk. Maternal vitamin intake during pregnancy was indicative of a protective effect (OR 0.75, 95%-CI: 0.56-1.01). No association was seen for maternal smoking during pregnancy or working during pregnancy. We found little evidence that the considered birth factors were related to brain tumour risk among children and adolescents.

Meta-analysis of mould and dampness exposure on asthma and allergy in eight European birth cohorts: an ENRIECO initiative

Background:  Several cross-sectional studies during the past 10 years have observed an increased risk of allergic outcomes for children living in damp or mouldy environments. Objective:  The objective of this study was to investigate whether reported mould or dampness exposure in early life is associated with the development of allergic disorders in children from eight European birth cohorts. Methods:  We analysed data from 31 742 children from eight ongoing European birth cohorts. Exposure to mould and allergic health outcomes were assessed by parental questionnaires at different time points. Meta-analyses with fixed- and random-effect models were applied. The number of the studies included in each analysis varied based on the outcome data available for each cohort. Results:  Exposure to visible mould and/or dampness during first 2 years of life was associated with an increased risk of developing asthma: there was a significant association with early asthma symptoms in meta-analyses of four cohorts [0–2 years: adjusted odds ratios (aOR), 1.39 (95%CI, 1.05–1.84)] and with asthma later in childhood in six cohorts [6–8 years: aOR, 1.09(95%CI, 0.90–1.32) and 3–10 years: aOR, 1.10 (95%CI, 0.90–1.34)]. A statistically significant association was observed in six cohorts with symptoms of allergic rhinitis at school age [6–8 years: aOR, 1.12 (1.02–1.23)] and at any time point between 3 and 10 years [aOR, 1.18 (1.09–1.28)]. Conclusion:  These findings suggest that a mouldy home environment in early life is associated with an increased risk of asthma particularly in young children and allergic rhinitis symptoms in school-age children.

European birth cohorts for environmental health research

Many pregnancy and birth cohort studies investigate the health effects of early-life environmental contaminant exposure. An overview of existing studies and their data is needed to improve collaboration, harmonization, and future project planning.

Effect of pregnancy and birth on the course of myasthenia gravis before or after transsternal radical thymectomy

OBJECTIVE: Myasthenia gravis (MG) affects women at childbearing age. Therefore, the question arises if these patients should become pregnant and if thymectomy has a positive effect on the course of MG in pregnant patients. METHODS: Fifteen pregnancies had been followed retrospectively. All patients underwent transsternal radical thymectomy for MG. The course of MG in the period before, during, and after the pregnancy was scored according to Ossermann's classification. The effect of thymectomy on delivery and on the newborns was evaluated. RESULTS: Patients were divided in two groups: pregnancies before (group I, n=8) and after (group II, n=7) thymectomy. During pregnancy, in group I, one deterioration was observed and in seven patients the disease was unchanged. In group II, one deterioration, five unchanged courses, and one improvement were observed. In the postpartum period, in group I, seven patients did not change and one improved. In group II, two deteriorations, three unchanged courses, and two improvements were observed. Before pregnancy, group II patients were in a better Ossermann stage in comparison with those in group I. Eight of the 12 deliveries were spontaneous (three abortus). Myasthenic symptoms were observed in two newborns in group I. CONCLUSION: Our data suggest that MG is not prohibitive to have children. The course of MG after transsternal radical thymectomy is often ameliorated. A better MG-stage, reached after thymectomy, before pregnancy seems to be correlated with a better course during pregnancy.

Longitudinal data on telomere length in leukocytes from newborn baboons support a marked drop in stem cell turnover around 1 year of age

Stem cells of various tissues are typically defined as multipotent cells with 'self-renewal' properties. Despite the increasing interest in stem cells, surprisingly little is known about the number of times stem cells can or do divide over a lifetime. Based on telomere-length measurements of hematopoietic cells, we previously proposed that the self-renewal capacity of hematopoietic stem cells is limited by progressive telomere attrition and that such cells divide very rapidly during the first year of life. Recent studies of patients with aplastic anemia resulting from inherited mutations in telomerase genes support the notion that the replicative potential of hematopoietic stem cells is directly related to telomere length, which is indirectly related to telomerase levels. To revisit conclusions about stem cell turnover based on cross-sectional studies of telomere length, we performed a longitudinal study of telomere length in leukocytes from newborn baboons. All four individual animals studied showed a rapid decline in telomere length (approximately 2-3 kb) in granulocytes and lymphocytes in the first year after birth. After 50-70 weeks the telomere length appeared to stabilize in all cell types. These observations suggest that hematopoietic stem cells, after an initial phase of rapid expansion, switch at around 1 year of age to a different functional mode characterized by a markedly decreased turnover rate.

Effects of female genital mutilation on birth outcomes in Switzerland

OBJECTIVE: The primary aim of this study was to determine the desires and wishes of pregnant patients vis-à-vis their external genital anatomy after female genital mutilation (FGM) in the context of antenatal care and delivery in a teaching hospital setting in Switzerland. Our secondary aim was to determine whether women with FGM and non-mutilated women have different fetal and maternal outcomes. DESIGN: A retrospective case-control study. SETTING: A teaching hospital. POPULATION: One hundred and twenty-two patients after FGM who gave consent to participate in this study and who delivered in the Department of Obstetrics and Gynaecology in the University Hospital of Berne and 110 controls. METHODS: Data for patients' wishes concerning their FGM management, their satisfaction with the postpartum outcome and intrapartum and postpartum maternal and fetal data. As a control group, we used a group of pregnant women without FGM who delivered at the same time and who were matched for maternal age. MAIN OUTCOME MEASURES: Patients' satisfaction after delivery and defibulation after FGM, maternal and fetal delivery data and postpartum outcome measures. RESULTS: Six percent of patients wished to have their FGM defibulated antenatally, 43% requested a defibulation during labour, 34% desired a defibulation during labour only if considered necessary by the medical staff and 17% were unable to express their expectations. There were no differences for FGM patients and controls regarding fetal outcome, maternal blood loss or duration of delivery. FGM patients had significantly more often an emergency Caesarean section and third-degree vaginal tears, and significantly less first-degree and second-degree tears. CONCLUSION: An interdisciplinary approach may support optimal antenatal and intrapartum management and also the prevention of FGM in newborn daughters.

Pregnancy and birth cohort resources in europe: a large opportunity for aetiological child health research

BACKGROUND During the past 25 years, many pregnancy and birth cohorts have been established. Each cohort provides unique opportunities for examining associations of early-life exposures with child development and health. However, to fully exploit the large amount of available resources and to facilitate cross-cohort collaboration, it is necessary to have accessible information on each cohort and its individual characteristics. The aim of this work was to provide an overview of European pregnancy and birth cohorts registered in a freely accessible database located at http://www.birthcohorts.net. METHODS European pregnancy and birth cohorts initiated in 1980 or later with at least 300 mother-child pairs enrolled during pregnancy or at birth, and with postnatal data, were eligible for inclusion. Eligible cohorts were invited to provide information on the data and biological samples collected, as well as the timing of data collection. RESULTS In total, 70 cohorts were identified. Of these, 56 fulfilled the inclusion criteria encompassing a total of more than 500,000 live-born European children. The cohorts represented 19 countries with the majority of cohorts located in Northern and Western Europe. Some cohorts were general with multiple aims, whilst others focused on specific health or exposure-related research questions. CONCLUSION This work demonstrates a great potential for cross-cohort collaboration addressing important aspects of child health. The web site, http://www.birthcohorts.net, proved to be a useful tool for accessing information on European pregnancy and birth cohorts and their characteristics.

Preterm birth, infant weight gain, and childhood asthma risk: A meta-analysis of 147,000 European children

BACKGROUND Preterm birth, low birth weight, and infant catch-up growth seem associated with an increased risk of respiratory diseases in later life, but individual studies showed conflicting results. OBJECTIVES We performed an individual participant data meta-analysis for 147,252 children of 31 birth cohort studies to determine the associations of birth and infant growth characteristics with the risks of preschool wheezing (1-4 years) and school-age asthma (5-10 years). METHODS First, we performed an adjusted 1-stage random-effect meta-analysis to assess the combined associations of gestational age, birth weight, and infant weight gain with childhood asthma. Second, we performed an adjusted 2-stage random-effect meta-analysis to assess the associations of preterm birth (gestational age <37 weeks) and low birth weight (<2500 g) with childhood asthma outcomes. RESULTS Younger gestational age at birth and higher infant weight gain were independently associated with higher risks of preschool wheezing and school-age asthma (P < .05). The inverse associations of birth weight with childhood asthma were explained by gestational age at birth. Compared with term-born children with normal infant weight gain, we observed the highest risks of school-age asthma in children born preterm with high infant weight gain (odds ratio [OR], 4.47; 95% CI, 2.58-7.76). Preterm birth was positively associated with an increased risk of preschool wheezing (pooled odds ratio [pOR], 1.34; 95% CI, 1.25-1.43) and school-age asthma (pOR, 1.40; 95% CI, 1.18-1.67) independent of birth weight. Weaker effect estimates were observed for the associations of low birth weight adjusted for gestational age at birth with preschool wheezing (pOR, 1.10; 95% CI, 1.00-1.21) and school-age asthma (pOR, 1.13; 95% CI, 1.01-1.27). CONCLUSION Younger gestational age at birth and higher infant weight gain were associated with childhood asthma outcomes. The associations of lower birth weight with childhood asthma were largely explained by gestational age at birth.

Participation in Further Education over the Life Course: a longitudinal study of three birth cohorts in the Federal Republic of Germany

In this paper we address the issue of who is most likely to participate in further training, for what reasons and at what stage of the life course. Special emphasis is given to the impact of labour-market policies to encourage further education and a person's individual or cohort possibilities to participate in further education. We apply a Cox proportional hazard model to data from the West German Life History Study, separately for women and men, within and outside the firm. Younger cohorts show not only higher proportions of participation in further education and training at early stages of the life course, they also continue to participate in higher numbers during later stages of the life course. General labour-force participation reduces and tenure with the same firm increases the propensity to participate in further education and training. Contrary to expectations, in Germany labour-market segmentation has been enhanced rather than reduced by further education and training policies, since in the firm-specific labour-market segment, i.e. skilled jobs in large firms, and in the public sector both women and men had a higher probability of participation. Particularly favourable conditions for participation in further education outside the firm prevailed during the first years of the labour promotion act (Arbeitsförderungsgesetz) between 1969 and 1974, but women did not benefit to the same extent as men. Training policies are, therefore, in need of continuous assessment based on a goal-achievement evaluation to avoid any unintended effects of such policies.

A new methodological approach for studying intergenerational mobility with an application to Swiss data

Despite the widespread interest in the topic and a vast international literature, very little is known about the development of intergenerational mobility in Switzerland. Based on a new harmonized database for Switzerland (comprising various surveys such as different waves of the ISSP, EVS, and the ESS), we provide a systematic account of changes in the link between social origin and destination over time (covering birth cohorts from around 1935 to 1980). We analyze effects of parental education and class on own educational achievement and social class for both men and women, using a refined variant of the methodological approach proposed by Jann and Combet (2012). The approach is based on the concept of proportional reduction of error (PRE) and features a number of advantages over more traditional approaches. For example, it provides smooth estimates of changes in social mobility that have a clear interpretation and it can easily incorporate control variables and multiple dimensions of parental characteristics. To evaluate the validity of our approach, we employ the oft-used log-multiplicative layer effect (a.k.a Unidiff) model (Xie 1992, Erikson and Goldthorpe 1992) as a benchmark. Results indicate that our approach performs well and produces qualitatively similar findings as Xie's model. For both men and women, effects of social origin initially decreased, but then, towards the end of the observation period, increased again. This u-shaped pattern, which can be observed with respect to both education and class, appears to be more pronounced for women than for men.

Cardiac medication during pregnancy, data from the ROPAC

BACKGROUND Data on pharmacological management during pregnancy are scarce. The aim of this study was to describe the type and frequency of cardiac medication used in pregnancy in patients with cardiovascular disease and to assess the relationship between medication use and fetal outcome. METHODS AND RESULTS Between 2007 and 2011 sixty hospitals in 28 countries enrolled 1321 pregnant women. All patients had structural heart disease (congenital 66%, valvular 25% or cardiomyopathy 7% or ischemic 2%). Medication was used by 424 patients (32%) at some time during pregnancy: 22% used beta-blockers, 8% antiplatelet agents, 7% diuretics, 2.8% ACE inhibitors and 0.5% statins. Compared to those who did not take medication, patients taking medication were older, more likely to be parous, have valvular heart disease and were less often in sinus rhythm. The odds ratio of fetal adverse events in users versus non-users of medication was 2.6 (95% CI 2.0-3.4) and after adjustment for cardiac and obstetric parameter was 2.0 (95% CI 1.4-2.7). Babies of patients treated with beta-blockers had a significantly lower adjusted birth weight (3140 versus 3240 g, p = 0.002). The highest rate of fetal malformation was found in patients taking ACE inhibitors (8%). CONCLUSION One third of pregnant women with heart disease used cardiac medication during their pregnancy, which was associated with an increased rate of adverse fetal events. Birth weight was significantly lower in children of patients taking beta-blockers. A randomized trial is needed to distinguish the effects of the medication from the effects of the underlying maternal cardiac condition.

Factors influencing the accuracy of fetal weight estimation with a focus on preterm birth at the limit of viability: a systematic literature review

BACKGROUND Fetal weight estimation (FWE) is an important factor for clinical management decisions, especially in imminent preterm birth at the limit of viability between 23(0/7) and 26(0/7) weeks of gestation. It is crucial to detect and eliminate factors that have a negative impact on the accuracy of FWE. DATA SOURCES In this systematic literature review, we investigated 14 factors that may influence the accuracy of FWE, in particular in preterm neonates born at the limit of viability. RESULTS We found that gestational age, maternal body mass index, amniotic fluid index and ruptured membranes, presentation of the fetus, location of the placenta and the presence of multiple fetuses do not seem to have an impact on FWE accuracy. The influence of the examiner's grade of experience and that of fetal gender were discussed controversially. Fetal weight, time interval between estimation and delivery and the use of different formulas seem to have an evident effect on FWE accuracy. No results were obtained on the impact of active labor. DISCUSSION This review reveals that only few studies investigated factors possibly influencing the accuracy of FWE in preterm neonates at the limit of viability. Further research in this specific age group on potential confounding factors is needed.

Twenty years' experience with the Swiss data registry for assisted reproductive medicine: outcomes, key trends and recommendations for improved practice.

QUESTIONS UNDER STUDY The impact of assisted reproductive technology (ART) on Swiss demography was quantified. From 1993 to 2012 the number of deliveries, including multiples, generated by ART was compared with overall delivery numbers. Swiss experts in ART collaborated in a consensus to increase successful outcomes, to reduce the incidence of complications of ART and to validate recommendations through statistical review of available data. METHODS Data generated between 1993 and 2012 and published by the Federal Office of Statistics (BfS) were compared with the Swiss database on ART (FIVNAT-CH) as organised by the Swiss Society of Reproductive Medicine (SGRM). From these analyses a panel of Swiss experts in ART extracted recommendations to improve current practice, to prevent complications related to ART and to recommend changes in current Swiss legislation dealing with ART. RESULTS Since 1993 the age of women giving birth rose together with the number of women asking for ART. This demographic trend was reflected in a rise in the number of deliveries generated by ART (in 2012: 2.2%) and the proportion of multiple births (in 2012: 17.6%). The outcome of ART was most negatively influenced by the age of the treated patient. The number of retrieved oocytes decisively impacted the likelihood of delivery, the risk of multiple births and the incidence of ovarian hyperstimulation syndrome. CONCLUSIONS Optimal ovarian stimulation should be designed for the retrieval of 10 to 15 oocytes per treatment. Swiss legislation should enable and stimulate a policy of elective single embryo transfer to avoid multiple births.