Influence of the COVID-19 pandemic on births and induced abortions in Southern Sweden: a register-based study.

BACKGROUND: Pandemics are linked with declining birth rates, but little is known about how the COVID-19 pandemic has influenced childbearing decisions. We aimed to investigate the associations between the COVID-19 pandemic and reproductive decisions, specifically to identify potential changes in the frequency of deliveries and induced abortions in Skåne, Sweden. METHODS: Using the Skåne Healthcare Register, we identified women aged 15-45 years who had at least one pregnancy-related care visit registered between 1 January 2013 and 11 November 11 2021. Deliveries and induced abortions were identified, and changes in weekly delivery and abortion counts were assessed using an interrupted time series design. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated from a Poisson regression model. RESULTS: During the study period we identified 129 131 deliveries and 38 591 abortions. Compared with the counterfactual (exposed interval assuming COVID-19 had not occurred), pandemic exposure was associated with fewer deliveries (RR 0.93; 95% CI 0.89 to 0.98). For abortions, pandemic exposure appeared to be associated with fewer abortions (RR 0.95; 95% CI 0.90 to 1.00); however, age-related differences were found. Among women aged 25 years and over, pandemic exposure was more strongly associated with fewer abortions. Contrastingly, among women aged under 25 years, abortions appeared to increase. CONCLUSIONS: The COVID-19 pandemic seemed to have contributed to a decline in births in Southern Sweden. During the same period, abortions declined in women in the older age range, but contrastingly increased among younger women.

Exposure to Paracetamol in Early Pregnancy and the Risk of Developing Cerebral Palsy: A Case-Control Study Using Serum Samples.

OBJECTIVE: To investigate whether maternal paracetamol use in early pregnancy is associated with cerebral palsy (CP) in offspring. STUDY DESIGN: We conducted a registry and biobank-based case-control study with mother-child pairs. We identified CP cases (n = 322) born between 1995 and 2014 from a nationwide CP-registry. Randomly selected controls (n = 343) and extra preterm controls (n = 258) were obtained from a birth registry. For each mother, a single serum sample from early pregnancy (gestation weeks 10-14) was retrieved from a biobank and analyzed for serum concentrations of paracetamol, categorized into unexposed (<1 ng/ml), mildly exposed (1-100 ng/ml), and highly exposed (>100 ng/ml), and in quartiles. Analyses were performed using logistic regression and adjusted for potential confounders. Separate analyses were conducted including only those children born preterm and only those born term. RESULTS: Of the 923 participants, 36.8% were unexposed, 53.2% mildly exposed, and 10% highly exposed to paracetamol. Overall, prenatal exposure to paracetamol was not associated with CP. Sensitivity and subgroup analyses showed no clear associations between paracetamol and CP across strata of term/preterm birth as well as subtypes of CP. CONCLUSIONS: The present study does not support an association between intrauterine exposure to paracetamol in early pregnancy and the risk of CP. However, it is important to stress that the exposure estimate is based on a single serum sample.

Update of the risk assessment of inorganic arsenic in food.

The European Commission asked EFSA to update its 2009 risk assessment on arsenic in food carrying out a hazard assessment of inorganic arsenic (iAs) and using the revised exposure assessment issued by EFSA in 2021. Epidemiological studies show that the chronic intake of iAs via diet and/or drinking water is associated with increased risk of several adverse outcomes including cancers of the skin, bladder and lung. The CONTAM Panel used the benchmark dose lower confidence limit based on a benchmark response (BMR) of 5% (relative increase of the background incidence after adjustment for confounders, BMDL05) of 0.06 µg iAs/kg bw per day obtained from a study on skin cancer as a Reference Point (RP). Inorganic As is a genotoxic carcinogen with additional epigenetic effects and the CONTAM Panel applied a margin of exposure (MOE) approach for the risk characterisation. In adults, the MOEs are low (range between 2 and 0.4 for mean consumers and between 0.9 and 0.2 at the 95th percentile exposure, respectively) and as such raise a health concern despite the uncertainties.

The Long-Term Mortality Effects Associated with Exposure to Particles and NOx in the Malmö Diet and Cancer Cohort.

In this study, the long-term mortality effects associated with exposure to PM10 (particles with an aerodynamic diameter smaller than or equal to 10 µm), PM2.5 (particles with an aerodynamic diameter smaller than or equal to 2.5 µm), BC (black carbon), and NOx (nitrogen oxides) were analyzed in a cohort in southern Sweden during the period from 1991 to 2016. Participants (those residing in Malmö, Sweden, born between 1923 and 1950) were randomly recruited from 1991 to 1996. At enrollment, 30,438 participants underwent a health screening, which consisted of questionnaires about lifestyle and diet, a clinical examination, and blood sampling. Mortality data were retrieved from the Swedish National Cause of Death Register. The modeled concentrations of PM10, PM2.5, BC, and NOx at the cohort participants' home addresses were used to assess air pollution exposure. Cox proportional hazard models were used to estimate the associations between long-term exposure to PM10, PM2.5, BC, and NOx and the time until death among the participants during the period from 1991 to 2016. The hazard ratios (HRs) associated with an interquartile range (IQR) increase in each air pollutant were calculated based on the exposure lag windows of the same year (lag0), 1-5 years (lag1-5), and 6-10 years (lag6-10). Three models were used with varying adjustments for possible confounders including both single-pollutant estimates and two-pollutant estimates. With adjustments for all covariates, the HRs for PM10, PM2.5, BC, and NOx in the single-pollutant models at lag1-5 were 1.06 (95% CI: 1.02-1.11), 1.01 (95% CI: 0.95-1.08), 1.07 (95% CI: 1.04-1.11), and 1.11 (95% CI: 1.07-1.16) per IQR increase, respectively. The HRs, in most cases, decreased with the inclusion of a larger number of covariates in the models. The most robust associations were shown for NOx, with statistically significant positive HRs in all the models. An overall conclusion is that road traffic-related pollutants had a significant association with mortality in the cohort.

Gestational hypertension, preeclampsia, and gestational diabetes mellitus after high exposure to perfluoroalkyl substances from drinking water in Ronneby, Sweden.

BACKGROUND: Leakage of fire-fighting foam from an airfield caused contamination of the drinking water supplied to a third of the population in Ronneby, resulting in very high serum levels of predominantly perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS). The results of studies investigating the association between exposure to perfluorinated alkyl substances (PFAS) and pregnancy complications are inconsistent, and studies at high exposures of PFOS and PFHxS are lacking. OBJECTIVES: To investigate the association between exposure to high levels of PFAS and gestational hypertension and preeclampsia, and gestational diabetes mellitus. METHODS: We retrieved data on 27 292 childbirths between 1995 and 2013 from the National Medical Birth Register for women that had a residential address in Blekinge county for at least one year before delivery. Residential history was used as a proxy for exposure by categorizing women into high-, intermediate-, or background exposed based on their residential address during the five-year period before childbirth. Data on confounders were retrieved from administrative registers. The outcomes were defined based on International Classification of Diseases codes. We used logistic regression to estimate odds ratios (OR) for gestational hypertension and preeclampsia, and gestational diabetes mellitus. We also investigated effect modification by fetal sex. RESULTS: We found no evidence of increased risk of gestational hypertension and preeclampsia (OR 0.80; CI 0.63-1.03), nor gestational diabetes (OR 1.03; CI 0.67-1.58) after high PFAS exposure. There was no effect modification by fetal sex. DISCUSSION: This was the first study to investigate the association between high exposure to PFOS and PFHxS and pregnancy complications. The results from this study add important knowledge to public health management as new hotspots with high levels of PFAS are continuously discovered.

Maternal Serum Concentrations of Per- and Polyfluoroalkyl Substances in Early Pregnancy and Small for Gestational Age in Southern Sweden.

Small for gestational age (SGA) is considered an adverse birth outcome. Per- and polyfluoralkyl substances (PFAS) have become increasingly investigated as contributing environmental factors, thus far with inconclusive results. The current study aimed to investigate the hypothesized association between increased maternal PFAS levels in early pregnancy and an increased risk for SGA birth. This population-based study used data from a sample of children born in Scania, Southern Sweden, between 1995 and 2009. Two groups were compared: cases born with SGA (n = 298) and non-SGA controls (n = 580). The cases consisted of two subgroups: one included women whose children's growth in late pregnancy was in the lowest quartile, and another included women from the remaining growth quartiles. Corresponding maternal serum samples were collected from a biobank and analyzed for concentrations of four types of PFAS: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The results were combined with information from birth registers and analyzed using Mann-Whitney U-tests and logistic regression-unadjusted as well as adjusted for potential confounders. In conclusion, elevated maternal concentrations of PFAS were not associated with an increased risk of SGA birth. However, significant ORs were observed in a subgroup analysis restricted to women of Nordic origin (unadjusted OR 3.2 and adjusted OR 2.4) for PFHxS.

Exposure to per- and polyfluoroalkyl substances in early pregnancy and risk of cerebral palsy in children.

BACKGROUND: Most cerebral palsy (CP) cases have an unexplained etiology, but a role for environmental exposures has been suggested. One purported environmental risk factor is exposure to endocrine-disrupting pollutants specifically per- and polyfluoroalkyl substances (PFAS). OBJECTIVES: We investigated the association between prenatal PFAS exposures and CP in Swedish children. METHODS: In this case-control study, 322 CP cases, 343 population controls, and 258 preterm controls were identified from a birth registry in combination with a CP follow-up program from 1995 to 2014 and linked to a biobank which contains serum samples from week 10-14 of pregnancy. Maternal serum concentrations of four PFAS compounds: perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS) were analyzed using liquid chromatography-tandem-mass-spectrometry. We estimated odds ratios (ORs) and 95 % confidence intervals (CIs) for CP and each PFAS in quartiles and as continuous variables controlling for various sociodemographic and lifestyle factors. RESULTS: In crude and adjusted analyses, we did not find consistent evidence of associations between serum PFHxS, PFOA, PFNA, PFOS and concentrations in early pregnancy and CP, except in preterm infants. The ORs comparing the highest PFAS quartiles to the lowest were 1.05 (95 % CI: 0.63-1.76), 0.96 (95 % CI: 0.55-1.68), 0.71 (95 % CI: 0.41-1.25), and 1.17 (95 % CI: 0.61-2.26), for PFHxS, PFOA, PFNA, and PFOS, respectively. Some positive associations were observed for preterm infants, but the results were imprecise. Similar patterns were observed in analyses treating PFAS as continuous variables. CONCLUSIONS: In this study, we found little evidence that early pregnancy prenatal exposure to PFHxS, PFOA, PFNA, or PFOS increases the risk of CP. However, some positive associations were observed for preterm cases and warrant further investigation.

Occupational risk of SARS-CoV-2 infection: a nationwide register-based study of the Danish workforce during the COVID-19 pandemic, 2020-2021.

OBJECTIVE: Most earlier studies on occupational risk of COVID-19 covering the entire workforce are based on relatively rare outcomes such as hospital admission and mortality. This study examines the incidence of SARS-CoV-2 infection by occupational group based on real-time PCR (RT-PCR) tests. METHODS: The cohort includes 2.4 million Danish employees, 20-69 years of age. All data were retrieved from public registries. The incidence rate ratios (IRRs) of first-occurring positive RT-PCR test from week 8 of 2020 to week 50 of 2021 were computed by Poisson regression for each four-digit Danish Version of the International Standard Classification of Occupations job code with more than 100 male and 100 female employees (n=205). Occupational groups with low risk of workplace infection according to a job exposure matrix constituted the reference group. Risk estimates were adjusted by demographic, social and health characteristics including household size, completed COVID-19 vaccination, pandemic wave and occupation-specific frequency of testing. RESULTS: IRRs of SARS-CoV-2 infection were elevated in seven healthcare occupations and 42 occupations in other sectors, mainly social work activities, residential care, education, defence and security, accommodation and transportation. No IRRs exceeded 2.0. The relative risk in healthcare, residential care and defence/security declined across pandemic waves. Decreased IRRs were observed in 12 occupations. DISCUSSION: We observed a modestly increased risk of SARS-CoV-2 infection among employees in numerous occupations, indicating a large potential for preventive actions. Cautious interpretation of observed risk in specific occupations is needed because of methodological issues inherent in analyses of RT-PCR test results and because of multiple statistical tests.

Maternal serum vitamin D level in early pregnancy and risk for preeclampsia: A case-control study in Southern Sweden.

BACKGROUND: Preeclampsia is considered a major cause of maternal and fetal morbidity and mortality. The aim of the present case-control study in Sweden was to assess the hypothesized association between low serum vitamin D concentrations in early pregnancy and the risk of developing preeclampsia since vitamin D may play a role in early placental development. METHODS: The study included 296 women diagnosed with preeclampsia (cases) and 580 healthy pregnant women (controls). Serum samples were obtained from a biobank of samples collected in early pregnancy including almost all pregnancies in Southern Sweden. Concentrations of 25-hydroxyvitamin D3 (vitamin D) were analyzed using liquid chromatography-tandem-mass-spectrometry (LC/MS/MS). The cases were divided into two categories: i) infants were born before gestational week 34 (early onset) and/or born small-for-gestational age (SGA)(n = 51), ii) and others defined as late onset (n = 245). Vitamin D concentrations were analyzed both as a continuous and a categorized variable. RESULTS: When all preeclampsia cases were included in the analyses no consistent patterns were observed. However, the median serum concentrations of vitamin D were significantly lower among the cases who were early onset and/or were born SGA (median 39.2 nmol/L, range 1.2-93.6) as compared to the controls (49.0 nmol/L, 0.1-219; p = 0.01). In addition, high concentrations were statistically significantly associated with a decreased risk of preeclampsia (>66.9 vs ≤30.1 nmol/L; crude OR 0.39, 95% CI 0.16-0.96). When potential confounders were included in the models the associations were even more pronounced. CONCLUSIONS: Our results support the hypothesis that vitamin D deficiency is a risk factor for preeclampsia, but only in preeclampsia cases who were early-onset and/or were born SGA. Preeclampsia is not a homogenous condition and more studies are needed before vitamin D supplementation during pregnancy can be recommended.

COVID-19-related hospital admission in spouses of partners in at-risk occupations.

OBJECTIVE: This study aimed to quantify the risk of COVID-19-related hospital admission in spouses living with partners in at-risk occupations in Denmark during 2020-21. METHODS: Within a registry-based cohort of all Danish employees (N=2 451 542), we identified cohabiting couples, in which at least one member (spouse) held a job that according to a job exposure matrix entailed low risk of occupational exposure to SARS-CoV-2 (N=192 807 employees, 316 COVID-19 hospital admissions). Risk of COVID-19-related hospital admission in such spouses was assessed according to whether their partners were in jobs with low, intermediate or high risk for infection. Overall and sex-specific incidence rate ratios (IRR) of COVID-19-related hospital admission were computed by Poisson regression with adjustment for relevant covariates. RESULTS: The risk of COVID-19-related hospital admission was increased among spouses with partners in high-risk occupations [adjusted IRR (IRRadj)1.59, 95% confidence interval (CI) 1.1-2.2], but not intermediate-risk occupations (IRRadj 0.97 95% 0.8-1.3). IRR for having a partner in a high-risk job was elevated during the first three pandemic waves but not in the fourth (IRRadj 0.48 95% CI 0.2-1.5). Sex did not modify the risk of hospital admission. CONCLUSIONS: SARS-CoV-2 transmission at the workplace may pose an increased risk of severe COVID-19 among spouses in low-risk jobs living with partners in high-risk jobs, which emphasizes the need for preventive measures at the workplace in future outbreaks of epidemic contagious disease. When available, effective vaccines seem essential.

Occupational risk of COVID-19 related hospital admission in Denmark 2020-2021: a follow-up study.

OBJECTIVE: Mounting evidence indicates increased risk of COVID-19 among healthcare personnel, but the evidence on risks in other occupations is limited. In this study, we quantify the occupational risk of COVID-19-related hospital admission in Denmark during 2020-2021. METHODS: The source population included 2.4 million employees age 20-69 years. All information was retrieved from public registers. The risk of COVID-19 related hospital admission was examined in 155 occupations with at least 2000 employees (at-risk, N=1 620 231) referenced to a group of mainly office workers defined by a COVID-19 job exposure matrix (N=369 341). Incidence rate ratios (IRR) were computed by Poisson regression. RESULTS: During 186 million person-weeks of follow-up, we observed 2944 COVID-19 related hospital admissions in at-risk occupations and 559 in referents. Adjusted risk of such admission was elevated in several occupations within healthcare (including health care assistants, nurses, medical practitioners and laboratory technicians but not physiotherapists or midwives), social care (daycare assistants for children aged 4-7, and nursing aides in institutions and private homes, but not family daycare workers) and transportation (bus drivers, but not lorry drivers). Most IRR in these at-risk occupations were in the range of 1.5-3. Employees in education, retail sales and various service occupations seemed not to be at risk. CONCLUSION: Employees in several occupations within and outside healthcare are at substantially increased risk of COVID-19. There is a need to revisit safety measures and precautions to mitigate viral transmission in the workplace during the current and forthcoming pandemics.

Occupational risk of COVID-19 across pandemic waves: a two-year national follow-up study of hospital admissions.

OBJECTIVE: Assuming that preventive measures to mitigate viral transmission of SARS-CoV-2 at the workplace may have been improved in the course of the COVID-19 pandemic, we examined the occupational risk of COVID-19 related hospital admission across the four pandemic waves in Denmark between week 8, 2020, and week 50, 2021. METHODS: The study included 4416 cases of COVID-19 related hospital admissions among 2.4 million Danish employees aged 20-69 with follow-up in 2020 through 2021. At-risk industrial sectors and a reference population were defined a priory by a job-exposure matrix on occupational risk for COVID-19. Incidence rate ratios (IRR) and potential effect modification by pandemic wave were computed with Poisson regression adjusted for demographic, social and health factors including completed COVID-19 vaccination. RESULTS: We observed an overall elevated relative risk in four of six at-risk industrial sectors, but the pandemic wave only modified the risk among healthcare employees, where the excess risk from a high initial level declined to background levels during the latest waves in models not adjusting for COVID-19 vaccination. In social care, education and transport, the elevated risk was not modified by pandemic wave. CONCLUSION: Danish healthcare employees were to some extent protected against occupational transmission of SARS-CoV-2 during the two last pandemic waves even though the absolute risk conferred by occupation may not have been eliminated. Early vaccination of this group seems not to be the only explanation. The risk in other sectors remained elevated indicating a need to revisit preventive measures.

RUBIC (ReproUnion Biobank and Infertility Cohort): A binational clinical foundation to study risk factors, life course, and treatment of infertility and infertility-related morbidity.

BACKGROUND: Infertility affects 15%-25% of all couples during their reproductive life span. It is a significant societal and public health problem with potential psychological, social, and economic consequences. Furthermore, infertility has been linked to adverse long-term health outcomes. Despite the advanced diagnostic and therapeutic techniques available, approximately 30% of infertile couples do not obtain a live birth after fertility treatment. For these couples, there are no further options to increase their chances of a successful pregnancy and live birth. OBJECTIVES: Three overall questions will be studied: (1) What are the risk factors and natural life courses of infertility, early embryonic loss, and adverse pregnancy outcomes? (2) Can we develop new diagnostic and prognostic biomarkers for fecundity and treatment success? And (3) what are the health characteristics of women and men in infertile couples at the time of fertility treatment and during long-term follow-up? MATERIAL AND METHODS: ReproUnion Biobank and Infertility Cohort (RUBIC) is established as an add-on to the routine fertility management at Copenhagen University Hospital Departments in the Capital Region of Denmark and Reproductive Medicine Centre at Skåne University Hospital in Sweden. The aim is to include a total of 5000 couples equally distributed between Denmark and Sweden. The first patients were enrolled in June 2020. All eligible infertile couples are prospectively asked to participate in the project. Participants complete an extensive questionnaire and undergo a physical examination and collection of biospecimens (blood, urine, hair, saliva, rectal swabs, feces, semen, endometrial biopsies, and vaginal swabs). After the cohort is established, the couples will be linked to the Danish and Swedish national registers to obtain information on parental, perinatal, childhood, and adult life histories, including disease and medication history. This will enable us to understand the causes of infertility and identify novel therapeutic options for this important societal problem.

Temporal trends, 2000-2017, of perfluoroalkyl acid (PFAA) concentrations in serum of Swedish adolescents.

Per- and polyfluoroalkyl substances (PFAS) have been extensively used as surfactants because of their high stability and good water/oil-repellent properties. PFASs, especially perfluoroalkyl acids (PFAAs), have long biological half-lives, and exposure may cause adverse health effects in humans. We assessed temporal trends of concentrations of eight PFAAs in serum of Swedish adolescents (age 16-21 years) from the general population, and estimated the stability of PFAAs and serum samples after 6 years of storage. Repeated cross-sectional sampling was performed on five occasions (covering in total 1213 individuals, 83% males) in southern Sweden between 2000 and 2017. We analyzed serum for perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorododecanoic acid (PFDoDA) using liquid chromatography-tandem mass spectrometry. We assessed time trends using linear regression, long-term stability was assessed by reanalyzing samples collected 2013, and the comparison was done using Pearson correlation and Bland-Altman plots. PFHxS, PFOS, and PFOA decreased by 6.7% (CI: -7.0, -6.3%), 12.6% (CI: -12.9, -12.3%), and 6.5% (CI: -6.8, -6.1%) per year, respectively, and year of sampling explained 48-81% of the variation in concentrations. PFNA and PFDA seemed to increase up to 2009 and decrease thereafter. The trends were consistent after sensitivity analyses excluding women. Strong correlations of 94-97% were observed for concentrations of all compounds, except PFHxS, after storage. The observed trends closely followed the timing of manufacturers' voluntary phase-out initiatives, and of regulatory measures governing the compounds implemented in the EU and USA. This indicates that these actions mitigated the population's exposure to PFHxS, PFOS, and PFOA and, in recent years, to PFNA and PFDA, in southern Sweden. Furthermore, the results suggest that PFAAs remain stable in serum samples after long-term storage.

Serum amyloid P component: a new biomarker for low sperm concentration?

Serum amyloid P component (SAP) is present in seminal plasma, on spermatozoa, and in different tissues of the male reproductive tract, but its function is not known. The aims of this study were to determine if the concentration of SAP in seminal plasma is associated with commonly assessed semen parameters and to investigate if SAP could be a new, indirect biomarker for these parameters. In a cross-sectional study of 203 young volunteers, the concentration of SAP in seminal plasma was measured with a in-house developed enzyme-linked immunosorbent assay. Scatter plots, Pearson's correlation coefficients (r), and linear regression models were produced, and SAP showed a statistically significant correlation with sperm concentration (r = 0.75), sperm number (r = 0.68), semen volume (r = -0.19), progressive sperm motility (r = 0.24), and sperm immotility (r = -0.20). When the study group was dichotomized, SAP could be used to discriminate samples with a sperm concentration < or ≥5 × 106 ml-1, 15 × 106 ml-1, or 40 × 106 ml-1, and in receiver operating characteristic curves, the corresponding areas under the curves were 0.97, 0.93, and 0.82, respectively, with P < 0.001 for all three cutoff values studied. The concentration of SAP in seminal plasma showed a strong, positive correlation with the concentration of spermatozoa in semen. SAP may be used as a new indirect potential biomarker for sperm concentration in fresh and in frozen, stored samples. In addition, it is envisaged that the assay could be developed into a home fertility test to differentiate between a low and a normal sperm concentration.

Brain white matter lesions are associated with reduced hypothalamic volume and cranial radiotherapy in childhood-onset craniopharyngioma.

CONTEXT: White matter lesions (WML) are caused by obstruction of small cerebral vessels associated with stroke risk. Craniopharyngioma (CP) patients suffer from increased cerebrovascular mortality. OBJECTIVE: To investigate the effect of reduced HT volume and cranial radiotherapy (CRT) on WML in childhood-onset CP patients. DESIGN: A cross-sectional study of 41 patients (24 women) surgically treated childhood-onset CP in comparison to controls. SETTING: The South Medical Region of Sweden (2.5 million inhabitants). METHODS: With magnetic resonance imaging (MRI), we analysed qualitative measurement of WML based on the visual rating scale of Fazekas and quantitative automated segmentation of WML lesion. Also, measurement HT volume and of cardiovascular risk factors were analysed. RESULTS: Patients had a significant increase in WML volume (mL) (P = .001) compared to controls. Treatment with cranial radiotherapy (CRT) vs no CRT was associated with increased WML volume (P = .02) as well as higher Fazekas score (P = .001). WML volume increased with years after CRT (r = 0.39; P = .02), even after adjustment for fat mass and age. A reduced HT volume was associated with increased WML volume (r = -0.61, P < .001) and explained 26% of the variation (r2  = 0.26). Altogether, 47% of the WML volume was explained by age at investigation, HT volume and CRT. Patients with more WML also had higher cardiovascular risk. CONCLUSIONS: CRT may be associated directly with increased WML volume or indirectly with reduced HT volume associated with higher cardiovascular risk. Risk factors should be carefully monitored in these patients.

Associations between antenatal and perinatal risk factors and cerebral palsy: a Swedish cohort study.

OBJECTIVES: To investigate known and suggested risk factors associated with cerebral palsy in a Swedish birth cohort, stratified by gestational age. SETTING: Information on all births between 1995 and 2014 in Skåne, the southernmost region in Sweden, was extracted from the national birth register. PARTICIPANTS: The cohort comprised a total of 215 217 children. Information on confirmed cerebral palsy and subtype was collected from the national quality register for cerebral palsy (Cerebral Palsy Follow-up Surveillance Programme). PRIMARY AND SECONDARY OUTCOME MEASURES: We calculated the prevalence of risk factors suggested to be associated with cerebral palsy and used logistic regression models to investigate the associations between potential risk factors and cerebral palsy. All analyses were stratified by gestational age; term (≥37 weeks), moderately or late preterm (32-36 weeks) and very preterm (<32 weeks). RESULTS: In all, 381 (0.2 %) children were assigned a cerebral palsy diagnosis. Among term children, maternal preobesity/obesity, small for gestational age, malformations, induction, elective and emergency caesarian section, Apgar <7 at 5 min and admission to neonatal care were significantly associated with cerebral palsy (all p values<0.05). Among children born moderately or late preterm, small for gestational age, malformations, elective and emergency caesarian section and admission to neonatal care were all associated with cerebral palsy (all p values <0.05), whereas among children born very preterm no factors were significantly associated with the outcome (all p values>0.05). CONCLUSION: Our results support and strengthen previous findings on factors associated with cerebral palsy. The complete lack of significant associations among children born very preterm probably depends on to the small number of children with cerebral palsy in this group.

Exposure to polychlorinated compounds and cryptorchidism; A nested case-control study.

BACKGROUND: Maldescended testes or cryptorchidism is a genital birth defect that affects 2-9% of all male new-borns. Over the last 40 years there have been reports of increased prevalence in countries like the US, the UK and the Scandinavian countries. This possible increase has in some studies been linked to a foetal exposure to chemical pollutants. In this matched case-control study, we analysed maternal serum samples in early pregnancy for three different organochlorine compounds, to investigate whether the levels were associated with the risk of cryptorchidism. METHOD: Maternal serum samples taken during the first trimester of pregnancy from 165 cases (boys born with cryptorchidism) and 165 controls, matched for birth year and maternal age, parity and smoking habits during the pregnancy, were retrieved from the Southern Sweden Maternity Biobank. The samples were analysed for 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153), dichlorodiphenyltrichloroethane (p,p'-DDE) and hexachlorobenzene (HCB), using gas chromatography mass spectrometry. Associations between exposure and cryptorchidism were evaluated by conditional logistic regression. RESULTS: We found no statistically significantly associations between exposure to these compounds and cryptorchidism, either when the exposure variables were used as a continuous variable, or when the exposure levels were divided in quartiles. CONCLUSION: We found no evidence of an association between maternal levels of PCB-153, p,p'-DDE or HCB during the pregnancy and the risk of having cryptorchidism in the sons.

Per- and Polyfluoroalkyl Substances in Early Pregnancy and Risk for Preeclampsia: A Case-Control Study in Southern Sweden.

Preeclampsia is one of the most common causes of perinatal and maternal morbidity/mortality. One suggested environmental risk factor is exposure to endocrine-disrupting pollutants such as per- and polyfluoroalkyl substances (PFAS). The present case-control study in southern Sweden aims to investigate the hypothesized association between serum concentrations of PFAS in early pregnancy and the risk of developing preeclampsia. The study included 296 women diagnosed with preeclampsia (cases) and 580 healthy pregnant women (controls). Maternal serum samples were obtained from a biobank of samples collected in early pregnancy in connection with screening for infections. Serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) were analyzed using liquid chromatography-tandem-mass-spectrometry (LC/MS/MS). Among primiparous women, there were no differences in PFAS concentrations in early pregnancy between the cases and the controls whereas among multipara women, the cases had significantly higher concentrations of PFNA (median concentrations were 0.44 and 0.38 ng/mL, p = 0.04). When individual PFAS were categorized into quartiles and adjustment for potential confounders was performed, the women in the highest quartiles had no significant increased risks of developing preeclampsia as compared with women in the lowest category. In conclusion, the present study provides limited support for the hypothesized association between PFAS and preeclampsia in a population with relatively low exposure levels.

Occupational exposure to whole-body vibrations and pregnancy complications: a nationwide cohort study in Sweden.

OBJECTIVES: Pregnancy complications are common contributors to perinatal mortality and morbidity. Still, the cause(s) of gestational hypertensive disorders and diabetes are largely unknown. Some occupational exposures have been inconsistently associated with pregnancy complications, but exposure to whole-body vibrations (WBV) has been largely overlooked even though it has been associated with adverse birth outcomes. Therefore, the aim was to assess whether occupational WBV exposure during pregnancy is associated with pregnancy complications in a nationwide, prospective cohort study. METHODS: The Fetal Air Pollution Exposure cohort was formed by merging multiple Swedish, national registers containing information on occupation during pregnancy and diagnosis codes, and includes all working women who gave birth between 1994 and 2014 (n=1 091 044). WBV exposure was derived from a job-exposure matrix and was divided into categories (0, 0.1-0.2, 0.3-0.4 and ≥0.5 m/s2). ORs with 95% CIs were calculated using logistic regression adjusted for potential confounders. RESULTS: Among women working full time (n=646 490), we found increased risks of all pregnancy complications in the highest exposure group (≥0.5 m/s2), compared with the lowest. The adjusted ORs were 1.76 (95% CI 1.41 to 2.20), 1.55 (95% CI 1.26 to 1.91) and 1.62 (95% CI 1.07 to 2.46) for preeclampsia, gestational hypertension and gestational diabetes, respectively, and were similar in all sensitivity analyses. There were no clear associations for part-time workers. CONCLUSIONS: The results suggest that women should not be exposed to WBV at/above the action limit value of 0.5 m/s2 (European directive) continuously through pregnancy. However, these results need further confirmation.