| 1. |
- Kuja-Halkola, Ralf, et al.
(författare)
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Reproductive stoppage in autism spectrum disorder in a population of 2.5 million individuals
- 2019
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Ingår i: Molecular Autism. - : BioMed Central. - 2040-2392. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: It has been suggested that parents of children with autism spectrum disorder (ASD) curtail their reproduction, a phenomenon known as reproductive stoppage. To investigate the presence of reproductive stoppage, we followed the reproduction in mothers of children with or without an ASD diagnosis using Swedish population-based registries.Methods: We followed all families with first child born in 1987 or later. In total 2,521,103 children, nested within 1,270,017 mothers, were included. Exposure was presence of ASD diagnosis in earlier born siblings, and outcome was considered as (1) inter-pregnancy interval and (2) number of subsequent children.Results: Analyses of inter-pregnancy intervals showed that the association differed across birth orders, with a lower rate of second children when first child had ASD diagnosis, but an increased rate of third and higher birth orders in families where a previous child had an ASD diagnosis. When all birth orders were simultaneously considered, families with a child with an ASD diagnosis were less likely to have another child (hazard ratio (HR), 0.79; 95% confidence interval [95% CI], 0.78-0.80). However, when adjusted for birth order, the association was close to null (HR, 0.97; 95% CI, 0.96-0.99), and after additional adjustments (maternal age, birth period, sex, paternal age, and maternal education), the association disappeared (HR, 1.00; 95% CI, 0.99-1.02). In analyses of subsequent children, after adjustment for covariates, families with an ASD diagnosis had 4% more subsequent children (rate ratio, 1.04; 95% CI, 1.03-1.05).Limitations: The study was undertaken in a country with largely tax-funded healthcare; results may not generalize to other societies. Following the current dominating umbrella concept of ASD, we did not differentiate between the ASD sub-diagnoses; it is possible that reproductive patterns can be dependent on ASD subtypes and the severity and composition of ASD phenotypes and comorbidities.Conclusions: This study does not support a universal reproductive stoppage effect in ASD families, when birth order and other factors are considered. Therefore, proper attention to birth order and other factors may alleviate potential bias in familial aggregation studies of ASD.
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| 2. |
- Ludvigsson, Jonas F., 1969-, et al.
(författare)
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Maternal Influenza A(H1N1) Immunization During Pregnancy and Risk for Autism Spectrum Disorder in Offspring
- 2020
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Ingår i: Annals of Internal Medicine. - : American College of Physicians. - 0003-4819 .- 1539-3704. ; 173:8, s. 597-604
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Tidskriftsartikel (refereegranskat)abstract
- Background: There are concerns that influenza vaccine exposure during pregnancy may be associated with increased risk for autism spectrum disorder (ASD).Objective: To examine the risk for ASD in offspring of mothers who were vaccinated against influenza A(H1N1)pdm09 ("swine flu") during pregnancy.Design: Population-based cohort study using nationwide registers.Setting: Seven health care regions in Sweden.Participants: Live births between October 2009 and September 2010, with follow-up through December 2016. In total, 39 726 infants were prenatally exposed to H1N1 vaccine (13 845 during the first trimester) and 29 293 infants were unexposed.Measurements: Cox regression was used to estimate hazard ratios (HRs) for the primary outcome, ASD, before and after adjustment for potential confounders. The secondary outcome was autistic disorder (AD).Results: Mean follow up was 6.7 years in both unexposed and exposed children. During follow-up, 394 (1.0%) vaccine-exposed and 330 (1.1%) unexposed children had a diagnosis of ASD. In adjusted analyses, prenatal exposure to H1N1 vaccination was not associated with a later diagnosis of ASD (adjusted HR [aHR], 0.95 [95% CI, 0.81 to 1.12]) or AD (aHR, 0.96 [CI, 0.80 to 1.16]). The 6-year standardized cumulative incidence difference between the unexposed and exposed children was 0.04% (CI, -0.09% to 0.17%) for ASD and 0.02% (CI, -0.09% to 0.14%) for AD. Restricting the analysis to vaccination in the first trimester of pregnancy did not influence risk estimates (aHR, 0.92 [CI, 0.74 to 1.16] for ASD and 0.91 [Cl, 0.70 to 1.18] for AD).Limitation: Data on H1N1 influenza infection are lacking.Conclusion: This large cohort study found no association between maternal H1N1 vaccination during pregnancy and risk for ASD in the offspring. Primary Funding Source: Swedish Research Council.
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| 3. |
- Silverman, Michael E., et al.
(författare)
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The risk factors for postpartum depression : A population-based study
- 2017
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Ingår i: Depression and anxiety (Print). - Hoboken, USA : John Wiley & Sons. - 1091-4269 .- 1520-6394. ; 34:2, s. 178-187
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Tidskriftsartikel (refereegranskat)abstract
- Background: Postpartum depression (PPD) can result in negative personal and child developmental outcomes. Only a few large population-based studies of PPD have used clinical diagnoses of depression and no study has examined how a maternal depression history interacts with known risk factors. The objective of this study was to examine the impact of a depression history on PPD and pre- and perinatal risk factors.Methods: A nationwide prospective cohort study of all women with live singleton births in Sweden from 1997 through 2008 was conducted. Relative risk (RR) of clinical depression within the first year postpartum and two-sided 95% confidence intervals were estimated.Results: The RR of PPD in women with a history of depression was estimated at 21.03 (confidence interval: 19.72-22.42), compared to those without. Among all women, PPD risk increased with advanced age (1.25 (1.13-1.37)) and gestational diabetes (1.70 (1.36-2.13)). Among women with a history of depression, pregestational diabetes (1.49 (1.01-2.21)) and mild preterm delivery also increased risk (1.20 (1.06-1.36)). Among women with no depression history, young age (2.14 (1.79-2.57)), undergoing instrument-assisted (1.23 (1.09-1.38)) or cesarean (1.64(1.07-2.50)) delivery, and moderate preterm delivery increased risk (1.36 (1.05-1.75)). Rates of PPD decreased considerably after the first postpartum month (RR = 0.27).Conclusions: In the largest population-based study to date, the risk of PPD was more than 20 times higher for women with a depression history, compared to women without. Gestational diabetes was independently associated with a modestly increased PPD risk. Maternal depression history also had a modifying effect on pre- and perinatal PPD risk factors.
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| 4. |
- Svensson, C, et al.
(författare)
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Maternal Effects for Preterm Birth : A Genetic Epidemiologic Study of 630,000 Families
- 2009
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 170:11, s. 1365-1372
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Tidskriftsartikel (refereegranskat)abstract
- This study was undertaken to disentangle the maternal genetic from the fetal genetic effects for preterm birth and to study the possibility of these effects being explained by known risk factors. By cross-linking of the population-based Swedish Multigeneration and Medical Birth registers, 989,027 births between 1992 and 2004 were identified. Alternating logistic regression was applied to model the familial clustering with pairwise odds ratios (PORs), and covariates were included to evaluate if the familial aggregation was explained by exposure to shared risk factors. Generalized linear mixed models were used to estimate the contribution of genetic and environmental effects. Sisters of women who had a preterm delivery had themselves an increased odds of having a preterm delivery (POR = 1.8, 95% confidence interval: 1.5, 2.1), while there was no corresponding increase in odds in families joined by brothers (POR = 1.1, 95% confidence interval: 0.9, 1.4). Twenty-five percent of the variation in preterm birth was explained by maternal genetic factors, whereas fetal genetic factors only marginally influenced the variation in liability. The increased odds ratio between offspring of sisters was independent of maternal risk factors for preterm birth, suggesting that the relative importance of maternal effects is not explained by these well-known risk factors.
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| 5. |
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| 6. |
- Azerkan, Fatima, et al.
(författare)
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Cervical screening participation and risk among Swedish-born and immigrant women in Sweden
- 2012
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 130:4, s. 937-947
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Tidskriftsartikel (refereegranskat)abstract
- Cervical cancer is one of the most common cancers among women worldwide, although cervical screening has reduced the incidence in many high-income countries. Low screening uptake among immigrant women may reflect differences in risk of cervical cancer. We investigated the degree of participation in cervical screening among immigrant and Swedish-born women and their concurrent risk of cervical cancer based on individual information on Pap smears taken both from organized and opportunistic screening. Mean degree of participation in cervical screening was estimated for women between 23 and 60 years from 1993 to 2005, stratified by birth region and age at migration. In Poisson regression models, we estimated relative risks (RRs), incidence rates and incidence rate ratios of cervical cancer for women adhering or not to the cervical screening program. We also assessed effect of adherence to screening on the risk of cervical cancer among immigrant groups compared to Swedish-born women. The degree of participation was 62% and 49% among Swedish-born and immigrant women, respectively, with large variations between immigrant groups. Participation was lowest among those immigrating at older ages. Swedish-born and immigrant women who where nonadherent to the cervical screening program had a fivefold excess risk of cervical cancer compared to adherent women. After adjustment for screening adherence, excess RRs of cervical cancer were statistically significant only for women from Norway and the Baltic States. Participation to screening is lower among immigrant than Swedish-born women, and adherence to the recommended screening intervals strongly prevents cervical cancer.
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| 7. |
- Barman, Malin, 1983, et al.
(författare)
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Nutritional impact on Immunological maturation during Childhood in relation to the Environment (NICE): a prospective birth cohort in northern Sweden
- 2018
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Ingår i: BMJ Open. - : BMJ. - 2044-6055 .- 2044-6055. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- © Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. INTRODUCTION: Prenatal and neonatal environmental factors, such as nutrition, microbes and toxicants, may affect health throughout life. Many diseases, such as allergy and impaired child development, may be programmed already in utero or during early infancy. Birth cohorts are important tools to study associations between early life exposure and disease risk. Here, we describe the study protocol of the prospective birth cohort, 'Nutritional impact on Immunological maturation during Childhood in relation to the Environment' (NICE). The primary aim of the NICE cohort is to clarify the effect of key environmental exposures-diet, microbes and environmental toxicants-during pregnancy and early childhood, on the maturation of the infant's immune system, including initiation of sensitisation and allergy as well as some secondary outcomes: infant growth, obesity, neurological development and oral health.METHODS AND ANALYSIS: The NICE cohort will recruit about 650 families during mid-pregnancy. The principal inclusion criterion will be planned birth at the Sunderby Hospital in the north of Sweden, during 2015-2018. Questionnaires data and biological samples will be collected at 10 time-points, from pregnancy until the children reach 4 years of age. Samples will be collected primarily from mothers and children, and from fathers. Biological samples include blood, urine, placenta, breast milk, meconium, faeces, saliva and hair. Information regarding allergic heredity, diet, socioeconomic status, lifestyle including smoking, siblings, pet ownership, etc will be collected using questionnaires. Sensitisation to common allergens will be assessed by skin prick testing and allergic disease will be diagnosed by a paediatrician at 1 and 4 years of age. At 4 years of age, the children will also be examined regarding growth, neurobehavioural and neurophysiological status and oral health.ETHICS AND DISSEMINATION: The NICE cohort has been approved by the Regional Ethical Review Board in Umeå, Sweden (2013/18-31M). Results will be disseminated through peer-reviewed journals and communicated on scientific conferences.
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| 8. |
- Bendel, Olof, et al.
(författare)
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Reappearance of hippocampal CA1 neurons after ischemia is associated with recovery of learning and memory
- 2005
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : Sage Publications. - 0271-678X .- 1559-7016. ; 25:12, s. 1586-1595
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Tidskriftsartikel (refereegranskat)abstract
- The pyramidal neurons of the hippocampal CA1 region are essential for cognitive functions such as spatial learning and memory, and are selectively destroyed after cerebral ischemia. To analyze whether degenerated CA1 neurons are replaced by new neurons and whether such regeneration is associated with amelioration in learning and memory deficits, we have used a rat global ischemia model that provides an almost complete disappearance (to approximately 3% of control) of CA1 neurons associated with a robust impairment in spatial learning and memory at two weeks after ischemia. We found that transient cerebral ischemia can evoke a massive formation of new neurons in the CA1 region, reaching approximately 40% of the original number of neurons at 90 days after ischemia (DAI). Co-localization of the mature neuronal marker neuronal nuclei with 5-bromo-2'-deoxyuridine in CA1 confirmed that neurogenesis indeed had occurred after the ischemic insult. Furthermore, we found increased numbers of cells expressing the immature neuron marker polysialic acid neuronal cell adhesion molecule in the adjacent lateral periventricular region, suggesting that the newly formed neurons derive from this region. The reappearance of CA1 neurons was associated with a recovery of ischemia-induced impairments in spatial learning and memory at 90 DAI, suggesting that the newly formed CA1 neurons restore hippocampal CA1 function. In conclusion, these results show that the brain has an endogenous capacity to form new nerve cells after injury, which correlates with a restoration of cognitive functions of the brain.
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| 9. |
- Bexelius, Christin, et al.
(författare)
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Estimation of Physical Activity Levels Using Cell Phone Questionnaires: A Comparison With Accelerometry for Evaluation of Between-Subject and Within-Subject Variations
- 2011
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Ingår i: Journal of Medical Internet Research. - : Journal of Medical Internet Research / Gunther Eysenbach. - 1438-8871. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical activity promotes health and longevity. Further elaboration of the role of physical activity for human health in epidemiological studies on large samples requires accurate methods that are easy to use, cheap, and possible to repeat. The use of telecommunication technologies such as cell phones is highly interesting in this respect. In an earlier report, we showed that physical activity level (PAL) assessed using a cell phone procedure agreed well with corresponding estimates obtained using the doubly labeled water method. However, our earlier study indicated high within-subject variation in relation to between-subject variations in PAL using cell phones, but we could not assess if this was a true variation of PAL or an artifact of the cell phone technique. less thanbrgreater than less thanbrgreater thanObjective: Our objective was to compare within-and between-subject variations in PAL by means of cell phones with corresponding estimates using an accelerometer. In addition, we compared the agreement of daily PAL values obtained using the cell phone questionnaire with corresponding data obtained using an accelerometer. less thanbrgreater than less thanbrgreater thanMethods: PAL was measured both with the cell phone questionnaire and with a triaxial accelerometer daily during a 2-week study period in 21 healthy Swedish women (20 to 45 years of age and BMI from 17.7 kg/m(2) to 33.6 kg/m(2)). The results were evaluated by fitting linear mixed effect models and descriptive statistics and graphs. less thanbrgreater than less thanbrgreater thanResults: With the accelerometer, 57% (95% confidence interval [CI] 40%-66%) of the variation was within subjects, while with the cell phone, within-subject variation was 76% (95% CI 59%-83%). The day-to-day variations in PAL observed using the cell phone questions agreed well with the corresponding accelerometer results. less thanbrgreater than less thanbrgreater thanConclusions: Both the cell phone questionnaire and the accelerometer showed high within-subject variations. Furthermore, day-to-day variations in PAL within subjects assessed using the cell phone agreed well with corresponding accelerometer values. Consequently, our cell phone questionnaire is a promising tool for assessing levels of physical activity. The tool may be useful for large-scale prospective studies.
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| 10. |
- Bexelius, Christin, et al.
(författare)
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Measures of Physical Activity Using Cell Phones: Validation Using Criterion Methods
- 2010
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Ingår i: JOURNAL OF MEDICAL INTERNET RESEARCH. - : JMIR Publications Inc.. - 1438-8871. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical activity is associated with reduced risks of many chronic diseases. Data collected on physical activity in large epidemiological studies is often based on paper questionnaires. The validity of these questionnaires is debated, and more effective methods are needed. Objective: This study evaluates repeated measures of physical activity level (PAL) and the feasibility of using a Java-based questionnaire downloaded onto cell phones for collection of such data. The data obtained were compared with reference estimates based on the doubly labeled water method and indirect calorimetry (PAL(ref)). Method: Using a Java-based cell phone application, 22 women reported their physical activity based on two short questions answered daily over a 14-day period (PAL(cell)). Results were compared with reference data obtained from the doubly labeled water method and indirect calorimetry (PAL(ref)). Results were also compared against physical activity levels assessed by two regular paper questionnaires completed by women at the end of the 14-day period (PAL(quest1) and PAL(quest2)). PAL(cell), PAL(quest1), and PAL(quest2) were compared with PAL(ref) using the Bland and Altman procedure. Results: The mean difference between PAL(cell), and PAL(ref) was small (0.014) with narrow limits of agreement (2SD = 0.30) Compared with PAL(ref) the mean difference was also small for PAL(quest1) and PAL(quest2) (0.004 and 0.07, respectively); however, the limits of agreement were wider (PAL(quest), 2SD = 0.50 and PAL(quest2), 2SD = 0.90). The test for trend was statistically significant for PAL(quest1) (slope of regression line = 0.79, P = .04) as well as for PAL(quest2) (slope of regression line = 1.58, P andlt; .001) when compared with PAL(ref). Conclusion: A Java-based physical activity questionnaire administered daily using cell phones produced PAL estimates that agreed well with PAL reference values. Furthermore, the limits of agreement between PAL obtained using cell phones, and reference values were narrower than for corresponding estimates obtained using paper questionnaires. Java-based questionnaires downloaded onto cell phones may be a feasible and cost-effective method of data collection for large-scale prospective studies of physical activity.
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