Breastfeeding duration is not associated with offspring inflammatory bowel disease risk in three population-based birth cohorts

BACKGROUND AND AIMS

Breastfeeding is critical for offspring health and development. While many observational studies report a protective effect between breastfeeding and inflammatory bowel disease (IBD), the relationship is not well-understood.

METHODS

We used prospectively collected data from three population-based birth cohorts (Danish National Birth Cohort, Norwegian Mother, Father, and Child Cohort, and All Babies in Southeast Sweden) and cross-linked national registers to ascertain the impact of breastfeeding duration on offspring IBD risk in each country, using adjusted Cox proportional regression analyses. We performed meta-analyses to determine pooled estimates.

RESULTS

We included 148,737 offspring and 169,510 offspring in analyses of exclusive and any breastfeeding duration, respectively. During median follow-up of 16.3 to 22.3 years, between 1996 and 2021, 543 offspring were diagnosed with IBD. In each country, there was no association between exclusive breastfeeding duration and offspring IBD risk after adjusting for birth year (Denmark), offspring sex, parental IBD status, maternal education, smoking during pregnancy, age at delivery, mode of delivery, preterm birth, and small for gestational age. The pooled adjusted hazard ratio for IBD was 1.24 (95% CI 0.94, 1.62, Q =0.16, I2= 0.0%) and 1.02 (95% CI 0.85, 1.21, Q=1.45, I2= 0.0%) among offspring breastfed exclusively for ≥6 months and <4 months, respectively, compared to 4-5 months. Similarly, we found null associations in pooled analyses of any breastfeeding duration and IBD, subtypes Crohn's disease and ulcerative colitis, as well as in cohort-specific analyses.

CONCLUSION

In prospectively collected data from three population-based birth cohorts, the duration of exclusive or any breastfeeding was not associated with offspring IBD risk.

Severe COVID-19 during pregnancy in Sweden, Norway, and Denmark

INTRODUCTION

Pregnancy is a risk factor for severe coronavirus disease 2019 (COVID-19) and adverse pregnancy outcomes. We aimed to explore maternal characteristics, pregnancy outcomes, vaccination status, and virus variants among pregnant women admitted to intensive care units (ICU) with severe COVID-19.

MATERIAL AND METHODS

We identified pregnant women admitted to ICU in Sweden (n = 96), Norway (n = 31), and Denmark (n = 16) because of severe COVID-19, from national registers and clinical databases between March 2020 and February 2022 (Denmark), August 2022 (Sweden), or December 2022 (Norway). Their background characteristics, pregnancy outcome, and vaccination status were compared with all birthing women and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test-positive pregnant women during the same time period. We calculated the number admitted to ICU per 10 000 birthing and per 1000 SARS-CoV-2 test-positive women during the Index, Alpha, Delta, and Omicron periods.

RESULTS

Women admitted to ICU had a higher mean body mass index, were more often of non-Scandinavian origin, had on average lower education and income levels, had a higher proportion of chronic and pregnancy-related conditions, delivered preterm, had neonates with low Apgar scores, and had more infants admitted to neonatal care, compared with all birthing and test-positive pregnant women. Of those admitted to ICU, only 7% had been vaccinated before admission. Overall, the highest proportion of women admitted to ICU per birthing was during the Delta period (4.1 per 10 000 birthing women). In Norway, the highest proportion admitted to ICU per test-positive pregnant women was during the Delta period (17.8 per 1000 test-positive), whereas the highest proportion of admitted per test-positive in Sweden and Denmark was seen during the Index period (15.4 and 8.9 per 1000 test-positive, respectively).

CONCLUSIONS

Admission to ICU because of COVID-19 in pregnancy was a rare event in the Scandinavian countries, but women who were unvaccinated, of non-Scandinavian origin, and with lower socio-economic status were at higher risk of admission to ICU. In addition, women admitted to ICU for COVID-19 had higher risk of adverse pregnancy outcomes.

Predicting mortality and visualizing health care spending by predicted mortality in Danes over age 65

Health care expenditure in the last year of life makes up a high proportion of medical spending across the world. This is often framed as waste, but this framing is only meaningful if it is known at the time of treatment who will go on to die. We analyze the distribution of health care spending by predicted mortality for the Danish population over age 65 over the year 2016, with one-year mortality predicted by a machine learning model based on sociodemographics and use of health care services for the two years before entry into follow-up. While a reasonably good model can be built, extremely few individuals have high ex-ante probability of dying, and those with a predicted mortality of more than 50% account for only 2.8% of total health care expenditure. Decedents outspent survivors by a factor of more than ten, but compared to survivors with similar predicted mortality they spent only 2.5 times as much. Our results suggest that while spending in the last year of life is indeed high, this is nearly all spent in situations where there is a reasonable expectation that the patient can survive.

Effectiveness evaluation of an antenatal care intervention addressing disparities to improve perinatal outcomes in Denmark: A nationwide register-based analysis of a cluster randomised controlled trial (MAMAACT)

OBJECTIVE

To evaluate whether MAMAACT, an antenatal care (ANC) intervention, aimed at reducing ethnic and social disparities in perinatal mortality, affected perinatal health outcomes.

DESIGN

Cluster randomised controlled trial.

SETTING

Nineteen of 20 maternity wards in Denmark.

POPULATION

All newborn children within a pre-implementation period (2014-2017) or an implementation period (2018-2019) (n = 188 658).

INTERVENTION

A 6-h training session for midwives in intercultural communication and cultural competence, two follow-up dialogue meetings, and health education materials for pregnant women on warning signs of pregnancy complications in six languages.

METHODS

Nationwide register-based analysis of the MAMAACT cluster randomised controlled trial. Mixed-effects logistic regression models were used to estimate the change in outcomes from pre- to post-implementation in the intervention group relative to the control group. Results were obtained for the overall study population and for children born to immigrants from low- to middle-income countries, separately. Models were adjusted for confounders selected a priori.

MAIN OUTCOME MEASURES

A composite perinatal mortality and morbidity outcome, including stillbirths, neonatal deaths, Apgar score <7, umbilical arterial pH < 7.0, admissions to a neonatal intensive care unit (NICU) >48 h, and NICU admissions for mechanical ventilation. Additional outcomes were the individual measures.

RESULTS

The intervention increased the risk of the composite outcome (adjusted odds ratio [aOR] 1.16, 95% confidence interval [CI] 0.99-1.34), mainly driven by differences in NICU admission risk (composite outcome excluding NICU, aOR 0.98, 95% CI 0.84-1.14). The intervention slightly increased the risk of low Apgar score and decreased the risk of low arterial pH, reflecting, however, small differences in absolute numbers. Other outcomes were unchanged.

CONCLUSIONS

Overall, the MAMAACT intervention did not improve the composite perinatal mortality and morbidity outcome (when excluding NICU admissions). The lack of effects may be due to contextual factors including organisational barriers in ANC hindering the midwives from changing practices.

Preterm birth after the introduction of COVID-19 mitigation measures in Norway, Sweden, and Denmark: a registry-based difference-in-differences study

BACKGROUND

Although some studies have reported a decrease in preterm birth following the start of the COVID-19 pandemic, the findings are inconsistent.

OBJECTIVE

This study aimed to compare the incidences of preterm birth before and after the introduction of COVID-19 mitigation measures in Scandinavian countries using robust population-based registry data.

STUDY DESIGN

This was a registry-based difference-in-differences study using births from January 2014 through December 2020 in Norway, Sweden, and Denmark. The changes in the preterm birth (<37 weeks) rates before and after the introduction of COVID-19 mitigation measures (set to March 12, 2020) were compared with the changes in preterm birth before and after March 12 from 2014 to 2019. The differences per 1000 births were calculated for 2-, 4-, 8-, 12-, and 16-week intervals before and after March 12. The secondary analyses included medically indicated preterm birth, spontaneous preterm birth, and very preterm (<32 weeks) birth.

RESULTS

A total of 1,519,521 births were included in this study. During the study period, 5.6% of the births were preterm in Norway and Sweden, and 5.7% were preterm in Denmark. There was a seasonal variation in the incidence of preterm birth, with the highest incidence during winter. In all the 3 countries, there was a slight overall decline in preterm births from 2014 to 2020. There was no consistent evidence of a change in the preterm birth rates following the introduction of COVID-19 mitigation measures, with difference-in-differences estimates ranging from 3.7 per 1000 births (95% confidence interval, -3.8 to 11.1) for the first 2 weeks after March 12, 2020, to -1.8 per 1000 births (95% confidence interval, -4.6 to 1.1) in the 16 weeks after March 12, 2020. Similarly, there was no evidence of an impact on medically indicated preterm birth, spontaneous preterm birth, or very preterm birth.

CONCLUSION

Using high-quality national data on births in 3 Scandinavian countries, each of which implemented different approaches to address the pandemic, there was no evidence of a decline in preterm births following the introduction of COVID-19 mitigation measures.

Health care expenditure in the last five years of life is driven by morbidity, not age: A national study of spending trajectories in Danish decedents over age 65

BACKGROUND

The high level of medical spending at the end of life is well-documented, but whether there is any real potential for cost reductions there is still in question, and studies have tended to overlook the costs of care.

AIM

To identify the most common health care spending trajectories over the last five years of life among older Danes, as well as the determinants of following a given trajectory.

METHODS

We linked Danish health registries to obtain data on all health care expenditure (including hospital treatment, prescription drugs, primary care and costs of communal care) over the last five years of life for all Danish decedents above age 65 in the period 2013 through 2017. A latent class analysis identified the most common cost trajectories, which were then related to socio-economical characteristics and health status at five years before death.

RESULTS

Total health care expenditures in the last five years of life were largely independent of age and cause of death. Costs of home care and residential care increased steeply with age at death whereas hospital costs decreased correspondingly. We found four main spending trajectories among decedents: 3 percent followed a late-rise trajectory, 11 percent had accelerating costs, and two groups of 43 percent each followed moderately or consistently high trajectories. The main predictor of total expenditure was the number of chronic diseases.

INTERPRETATION

Spending at the end of life is largely determined by chronic disease, and age and cause of death only determine the distribution of expenses into care and cure.

Searching for longevity hotspots in Denmark

While existing research on regions with high prevalence of centenarians has focused on selected candidate geographical regions, we explore the existence of hotspots in the whole of Denmark.

We performed a Kulldorff spatial scan, searching for regions of birth, and of residence at age 71, where an increased percentage of the cohort born 1906-1915 became centenarians. We then compared mortality hazards for these regions to the rest of the country.

We found a birth hotspot of 222 centenarians, 1.37 times more than expected, centered on a group of rural islands. Lower mortality hazards from age 71 onwards were confined to those born within the hotspot and persisted over a period of at least 30 years. At age 71, we found two residence-based hotspots of 348 respectively 238 centenarians, 1.46 and 1.44 times the expected numbers. One hotspot, located in high-income suburbs of the Danish capital, seems driven by selective in-migration of low-mortality individuals. The other hotspot seems driven by selective migration and lower morality among those born and residing in the hotspot.

Thus, Danish centenarian hotspots do exist. The locations and interpretation depend on whether we look at place of birth or of residence late in life.

Cerebrovascular disease after placental abruption: A population-based prospective cohort study

OBJECTIVE

To test whether abruption during pregnancy is associated with long-term cerebrovascular disease by assessing the incidence and mortality from stroke among women with abruption.

METHODS

We designed a population-based prospective cohort study of women who delivered in Denmark from 1978 to 2010. We used data from the National Patient Registry, Causes of Death Registry, and Danish Birth Registry to identify women with abruption, cerebrovascular events, and deaths. The outcomes included deaths resulting from stroke and nonfatal ischemic and hemorrhagic strokes. We fit Cox proportional hazards regression models for stroke outcomes, adjusting for the delivery year, parity, education, and smoking.

RESULTS

The median (interquartile range) follow-up in the nonabruption and abruption groups was 15.9 (7.8-23.8) and 16.2 (9.6-23.1) years, respectively, among 828,289 women with 13,231,559 person-years of follow-up. Cerebrovascular mortality rates were 0.8 and 0.5 per 10,000 person-years among women with and without abruption, respectively (hazard ratio [HR] 1.6, 95% confidence interval [CI] 0.9-3.0). Abruption was associated with increased rates of nonfatal ischemic stroke (HR 1.4, 95% CI 1.1-1.7) and hemorrhagic stroke (HR 1.4, 95% CI 1.1-1.9). The association of abruption and stroke was increased with delivery at <34 weeks, when accompanied by ischemic placental disease, and among women with ≥2 abruptions. These associations are less likely to have been affected by unmeasured confounding.

CONCLUSION

Abruption is associated with increased risk of cerebrovascular morbidity and mortality. Disruption of the hemostatic system manifesting as ischemia and hemorrhage may indicate shared etiologies between abruption and cerebrovascular complications.

Educational disparities in perinatal health in Denmark in the first decade of the 21st century: a register-based cohort study

OBJECTIVE

To investigate socioeconomic differences in six perinatal health outcomes in Denmark in the first decade of the 21st century.

DESIGN

A population-based cohort study.

SETTING

Danish national registries.

PARTICIPANTS

A total of 646 829 live born children and 3076 stillborn children (≥22+0 weeks of gestation) born in Denmark from 2000 to 2009. We excluded children with implausible relations between birth weight and gestational age (n=644), children without information on maternal country of origin (n=138) and implausible values of maternal year of birth (n=36).

MAIN OUTCOME MEASURES

We investigated the following perinatal health outcomes: stillbirth, neonatal and postneonatal mortality, small-for-gestational age, preterm birth grated into moderate preterm, very preterm and extremely preterm, and congenital anomalies registered in the first year of life.

RESULTS

Maternal educational level was inversely associated with all adverse perinatal outcomes. For all examined outcomes, the risk association displayed a clear gradient across the educational levels. The associations remained after adjustment for maternal age, maternal country of origin and maternal year of birth. Compared with mothers with vocational education, mothers with more than 15 years of education had an adjusted risk ratio for stillbirth of 0.64(95% CI 0.56 to 0.72). The corresponding adjusted risk ratios for neonatal mortality, postneonatal mortality, congenital anomalies, moderate preterm birth and small-for-gestational age were, respectively, 0.79(95% CI 0.67 to 0.93), 0.57(95% CI 0.42 to 0.78), 0.87(95% CI 0.83 to 0.91), 0.80(95% CI 0.77 to 0.83) and 0.83(95% CI 0.81 to 0.85).

CONCLUSION

Substantial educational inequalities in perinatal health were still present in Denmark in the first decade of the 21st century.

Mode of delivery is not associated with celiac disease

Purpose

The purpose of this study was to investigate the association between mode of delivery and the risk of celiac disease in two large population-based birth cohorts with different prevalence of diagnosed celiac disease.

Patients and methods

This is an observational register-based cohort study using two independent population cohorts. We used data from administrative registers and health administrative registers from Denmark and Norway and linked the data at the individual level. We included all children who were born in Denmark from January 1, 1995 to December 31, 2010 and all children who were born in Norway from January 1, 2004 to December 31, 2012.

Results

We included 1,051,028 children from Denmark. Cesarean sections were registered for 196,512 children (18.9%). Diagnosed celiac disease was registered for 1,395 children (0.13%). We included 537,457 children from Norway. Cesarean sections were registered for 90,128 children (16.8%). Diagnosed celiac disease was registered for 1,919 children (0.35%). We found no association between the mode of delivery and the risk of diagnosed celiac disease. The adjusted odds ratio for celiac disease for children delivered by any type of cesarean section compared to vaginal delivery was 1.11 (95% CI: 0.96–1.29) in the Danish cohort and 0.96 (95% CI: 0.84–1.09) in the Norwegian cohort. The adjusted odds ratio for celiac disease for children delivered by elective cesarean section compared to vaginal delivery was 1.20 (95% CI: 1.00–1.43) in the Danish cohort and 0.96 (95% CI: 0.79–1.17) in the Norwegian cohort.

Conclusion

In this large registry-based study, mode of delivery was not associated with an increased risk of diagnosed celiac disease.

Birth asphyxia in a Danish hospital uptake area was reduced after centralisation of deliveries

Severe birth asphyxia is a major cause of neonatal morbidity and long-term disability and may be prevented. However, the consequences of organisational changes are rarely evaluated. 
Methods: A cohort study comparing morbidity and mortality for term-born infants born with severe birth asphyxia, defined as an Apgar score ≤ 5 at 5 min., before and after major changes in the organisation of births in a Danish district.
 Results: The study included 77 infants born in 1997-2004 and 40 infants born in 2009-2013 who were admitted to a neonatal intensive care unit with an Apgar score ≤ 5 at 5 min. The rate of severe birth asphyxia was 1.9 per 1,000 births in the early years and 2.5 per 1,000 births for the 2009-2013 period (p = 0.16). Mortality in the first three years of life with severe birth asphyxia was 0.24 per 1,000 births in 1997-2004 (ten deaths) and 0.06 per 1,000 births in 2009-2013 (one death) (p = 0.20). We observed a highly significant difference between the two periods in the proportion of infants with neonatal seizures and age at discharge after birth. The outcome of death or cerebral palsy was present in 17/77 (22%) in the early period and 3/40 (7.5%) in the more recent period (p < 0.05).
 Conclusions: Over a relative short time period, death and disability due to severe birth asphyxia at term decreased significantly. This improvement is most likely explained by changes in the organisation of births in the hospital uptake area. as well as in treatment 
Funding: none.
Trial registration: not relevant.

Use of azathioprine and corticosteroids during pregnancy and birth outcome in women diagnosed with inflammatory bowel disease

BACKGROUND

The aim of this study was to describe prescription patterns for azathioprine and corticosteroids for pregnant women with inflammatory bowel diseases (IBD) before, during, and after pregnancy and to describe pregnancy outcomes.

METHODS

A cohort composed of all singleton pregnancies in Danish registries from 1996 to 2009 was divided by maternal IBD status: Crohn's disease (CD, n = 827), ulcerative colitis (UC, N = 1361), or no IBD diagnosis (background population, n = 814,231). The number of women with a prescription for azathioprine, local and systemic steroids within a 3-month period was computed for each of the pregnancy trimesters and the year before and after pregnancy. Outcomes of interest were stillbirth, perinatal mortality, low birth weight (LBW), preterm birth, and small for gestational age (SGA).

RESULTS

Number of prescriptions for azathioprine decreased just before and during pregnancy and increased after birth. Number of prescriptions for local and systemic corticosteroids decreased approximately 30% compared with before pregnancy and increased in the second trimester. There was an increased risk among mothers with IBD of LBW (adjusted odds ratio [adjOR]: CD: 2.25 [95% confidence interval {CI}, 1.74-2.91], UC: 1.81 [95% CI, 1.42-2.30]), preterm birth (adjOR: CD: 2.54 [95% CI, 2.04-3.15], UC: 1.86 [95% CI, 1.52-2.27]), and SGA (adjOR: CD: 1.99 [95% CI, 1.26-3.15], UC: 1.80 [95% CI, 1.18-2.75]).

CONCLUSION

Use of azathioprine and corticosteroids was often reduced or discontinued before or during early pregnancy followed by an increased use of corticosteroids later in pregnancy. Women diagnosed with IBD and with prescriptions for azathioprine and/or corticosteroids, have an increased risk of LBW, pre-term birth, and SGA. Birth Defects Research (Part A) 106:494-499, 2016. © 2016 Wiley Periodicals, Inc.

Focused breastfeeding counselling improves short- and long-term success in an early-discharge setting: A cluster-randomized study

Length of postnatal hospitalization has decreased and has been shown to be associated with infant nutritional problems and increase in readmissions. We aimed to evaluate if guidelines for breastfeeding counselling in an early discharge hospital setting had an effect on maternal breastfeeding self-efficacy, infant readmission and breastfeeding duration. A cluster randomized trial was conducted and assigned nine maternity settings in Denmark to intervention or usual care. Women were eligible if they expected a single infant, intended to breastfeed, were able to read Danish, and expected to be discharged within 50 hr postnatally. Between April 2013 and August 2014, 2,065 mothers were recruited at intervention and 1,476 at reference settings. Results show that the intervention did not affect maternal breastfeeding self-efficacy (primary outcome). However, less infants were readmitted 1 week postnatally in the intervention compared to the reference group (adjusted OR 0.55, 95% CI 0.37, -0.81), and 6 months following birth, more infants were exclusively breastfed in the intervention group (adjusted OR 1.36, 95% CI 1.02, -1.81). Moreover, mothers in the intervention compared to the reference group were breastfeeding more frequently (p < .001), and spend more hours skin to skin with their infants (p < .001). The infants were less often treated for jaundice (p = 0.003) and there was more paternal involvement (p = .037). In an early discharge hospital setting, a focused breastfeeding programme concentrating on increased skin to skin contact, frequent breastfeeding, good positioning of the mother infant dyad, and enhanced involvement of the father improved short-term and long-term breastfeeding success.

Cardiovascular Disease in Relation to Placental Abruption: A Population-Based Cohort Study from Denmark

BACKGROUND

Cardiovascular (CVD) complications stemming from vascular dysfunction have been widely explored in the setting of preeclampsia. However, the impact of abruption, a strong indicator of microvascular disturbance, on the risk of CVD mortality and morbidity remains poorly characterised.

METHODS

We designed a cohort analysis of 828 289 women who delivered singletons in Denmark between 1978 and 2010. We linked the National Patient Registry and the Registry of Causes of Death to the Danish Birth Registry to ascertain CVD events. We estimated CVD risks in relation to abruption from Cox proportional hazards regression following adjustments for confounders.

RESULTS

With 13 231 562 person-years of follow-up of women with at least one delivery, 11 829 pregnancies were complicated by abruption. The median (interquartile range) follow-up in the non-abruption and abruption groups was 16 (8, 24) and 18 (10, 25) years, respectively. CVD mortality rates in women with and without abruption were 0.9 and 0.3 per 10 000 person-years, respectively (adjusted hazard ratio (HR) 2.7, 95% confidence interval (CI) 1.5, 5.0). The corresponding CVD morbidity complication rates were 16.7 and 10.0 per 10 000 person-years, respectively (HR 1.5, 95% CI 1.4, 1.8). The increased risks were evident for ischaemic heart disease, acute myocardial infarction, hypertensive heart disease, non-rheumatic valvular disease, and congestive heart failure.

CONCLUSIONS

This study shows increased hazards of CVD morbidity and mortality in relation to abruption. A better understanding of the pathogenesis of distorted placental microvasculature is needed as this appears to be a harbinger of CVD later in life.

Exacerbations of asthma during pregnancy: Impact on pregnancy complications and outcome

Asthma is common among pregnant women, and the incidence of asthma exacerbations during pregnancy is high. This literature review provides an overview of the impact of exacerbations of asthma during pregnancy on pregnancy-related complications. The majority of published retrospective studies reveal that asthma exacerbations during pregnancy increase the risk of pre-eclampsia, gestational diabetes, placental abruption and placenta praevia. Furthermore, these women also have higher risk for breech presentation, haemorrhage, pulmonary embolism, caesarean delivery, maternal admission to the intensive care unit and longer postpartum hospital stay. Asthma has been associated with increased risk of intrauterine growth retardation, small-for-gestational age, low birth weight, infant hypoglycaemia and preterm birth, but more recent prospective studies have not revealed significant associations with regard to these outcomes. In conclusion, asthma exacerbations during pregnancy are associated with complications of pregnancy, labour and delivery. Prevention of exacerbations is essential to reduce the risk of complications and poor outcome.

Use of asthma medication during pregnancy and risk of specific congenital anomalies: A European case-malformed control study

BACKGROUND

Pregnant women with asthma need to take medication during pregnancy.

OBJECTIVE

We sought to identify whether there is an increased risk of specific congenital anomalies after exposure to antiasthma medication in the first trimester of pregnancy.

METHODS

We performed a population-based case-malformed control study testing signals identified in a literature review. Odds ratios (ORs) of exposure to the main groups of asthma medication were calculated for each of the 10 signal anomalies compared with registrations with nonchromosomal, nonsignal anomalies as control registrations. In addition, exploratory analyses were done for each nonsignal anomaly. The data set included 76,249 registrations of congenital anomalies from 13 EUROmediCAT registries.

RESULTS

Cleft palate (OR, 1.63; 95% CI, 1.05-2.52) and gastroschisis (OR, 1.89; 95% CI, 1.12-3.20) had significantly increased odds of exposure to first-trimester use of inhaled β2-agonists compared with nonchromosomal control registrations. Odds of exposure to salbutamol were similar. Nonsignificant ORs of exposure to inhaled β2-agonists were found for spina bifida, cleft lip, anal atresia, severe congenital heart defects in general, or tetralogy of Fallot. None of the 4 literature signals of exposure to inhaled steroids were confirmed (cleft palate, cleft lip, anal atresia, and hypospadias). Exploratory analyses found an association between renal dysplasia and exposure to the combination of long-acting β2-agonists and inhaled corticosteroids (OR, 3.95; 95% CI, 1.99-7.85).

CONCLUSIONS

The study confirmed increased odds of first-trimester exposure to inhaled β2-agonists for cleft palate and gastroschisis and found a potential new signal for renal dysplasia associated with combined long-acting β2-agonists and inhaled corticosteroids. Use of inhaled corticosteroids during the first trimester of pregnancy seems to be safe in relation to the risk for a range of specific major congenital anomalies.

A Register-Based Study of Diseases With an Autosomal Recessive Origin in Small Children in Denmark According to Maternal Country of Origin

BACKGROUND

Compared with children born of Danish mothers, the mortality of children, born and living in Denmark, is significantly increased in those with a mother from Afghanistan, Iraq, Pakistan, Somalia, and Turkey. Consanguinity has been suggested to account for part of this disparity. Since information on consanguinity is lacking, this suggestion is difficult to test. With an indirect approach, we addressed this question by comparing the risk of diseases with autosomal recessive inheritance in children born in Denmark of Danish-born women and of women born in these five countries, respectively.

METHODS

All children born in Denmark (1994-2010) were followed until 5 years of age or end-of-study period for the risk of hospitalisation with diseases of autosomal recessive aetiology, and therefore considered consanguinity-related. Diagnoses of autosomal recessive diseases were identified using two different methods: a literature review of consanguinity-associated diseases and a search in the Online Catalogue of Human Genes and Genetic Disorders. Risks were also calculated for diseases with known non-autosomal recessive aetiology (considered non-consanguinity-related). We estimated adjusted hazard ratios for the diseases in children of foreign-born women compared with children of Danish-born women.

RESULTS

Compared with offspring of Danish-born women, the risk of a consanguinity-related disease was significantly increased in children of foreign-born women, although the absolute risk was low. The risk of non-consanguinity-related diseases did not differ between the groups compared.

CONCLUSIONS

The findings support the hypothesis that consanguinity accounts for some, however a minor part, of the disparity in child mortality among migrants in Denmark.

Epidemiology of cerebral palsy in Southern Denmark

INTRODUCTION

The aim of this study was to describe the prevalence, subtypes, severity and neuroimaging findings of cerebral palsy (CP) in a cohort of children born in Southern Denmark. Risk factors were analysed and aetiology considered.

METHODS

A population-based cohort study covering 17,580 live births from 2003 to 2008.

RESULTS

The study included 43 children diagnosed with CP. The overall prevalence of CP was 2.4 per 1,000 live births (95% confidence interval (CI): 1.8-3.2). The gestational age (GA)-specific prevalence ranged from 63.5 per 1,000 live births for GA < 32 weeks to 1.3 for GA ≥ 37 weeks. Almost half of the children were born preterm and 28% were from multiple pregnancies. The prevalence of CP was 1.8 per 1,000 in singletons and 15.4 per 1,000 in multiples. Low GA and birth weight were risk factors for CP, also after stratification for multiple births. Spastic CP was the predominating subtype of CP, and 24 children (56%) were able to walk independently. White-matter lesions were the most common magnetic resonance imaging finding, and the aetiology of CP was known in 37% of cases.

CONCLUSION

The overall prevalence of CP was slightly higher than that found in other Scandinavian studies due to its higher prevalence in the preterm group. Possible explanations include the high rate of multiple births in the background population. Neuroimaging findings were abnormal in the majority of children with CP, but aetiology could only be established in one third of the children. Primary prevention of CP is possible if the numbers of preterm births and multiple pregnancies can be reduced.

FUNDING

The Danish Cerebral Palsy Follow-up Programme is supported by the foundation "Ludvig og Sara Elsass Fond".

TRIAL REGISTRATION

2008-58-0034.

Maternal use of selective serotonin reuptake inhibitors and risk of miscarriage - assessing potential biases

BACKGROUND

The use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy has been associated with miscarriage, but the association may be biased by maternal mental illness, lifestyle and exposure misclassification.

METHODS

A register study on all pregnancies in Denmark between 1996 and 2009 was conducted using individualised data from the Danish National Patient Register, the Medical Birth Register, the Danish Psychiatric Central Register, the Danish National Prescription database and the Danish National Birth Cohort (DNBC).

RESULTS

A total of 1 191164 pregnancies were included in the study, of which 98275 also participated in the DNBC. Pregnancies exposed to SSRIs during or before pregnancy were more likely than unexposed pregnancies to result in first trimester miscarriage, hazard rate (HR)=1.08 [95% confidence interval (CI) 1.04, 1.13] and HR=1.26 [95% CI 1.16, 1.37], respectively. No difference was observed for second trimester miscarriage. SSRI-exposed pregnancies without a maternal depression/anxiety diagnosis from a psychiatric department were less likely to result in first trimester miscarriage than unexposed pregnancies with a diagnosis, HR=0.85 [95% CI 0.76, 0.95]. SSRI-exposed pregnancies were characterised by an unhealthier maternal lifestyle and mental health profile than unexposed pregnancies, whereas no convincing differences were observed between pregnancies exposed to SSRIs during versus before pregnancy. Substantial disagreement was found between prescriptions and self-reported use of SSRIs, but it did not affect the estimated hazard ratios.

CONCLUSION

Confounding by indication and lifestyle in pregnancy may explain the association between SSRI use and miscarriage.

Increased risk of severe congenital heart defects in offspring exposed to selective serotonin-reuptake inhibitors in early pregnancy--an epidemiological study using validated EUROCAT data

BACKGROUND

Previous studies suggest a possible association between maternal use of selective serotonin-reuptake inhibitors (SSRIs) during early pregnancy and congenital heart defects (CHD). The purpose of this study was to verify this association by using validated data from the Danish EUROCAT Register, and secondary, to investigate whether the risk differs between various socioeconomic groups.

METHODS

We conducted a cohort study based on Danish administrative register data linked with the Danish EUROCAT Register, which includes all CHD diagnosed in live births, fetal deaths and in pregnancies terminated due to congenital anomalies. The study population consisted of all registered pregnancies (n = 72,280) in Funen, Denmark in the period 1995-2008. SSRI-use was assessed using The Danish National Prescription Registry, information on marital status, maternal educational level, income, and country of origin from Statistics Denmark was used as indicators of socioeconomic situation, and the CHD were studied in subgroups defined by EUROCAT. Logistic Regression was used to investigate the association between redeemed prescriptions for SSRIs and CHD.

RESULTS

The risk of severe CHD in the offspring of the 845 pregnant women who used SSRIs during first trimester increased four times (AOR 4.03 (95% CI 1.75-9.26)). We found no increased risk of septal defects. Socioeconomic position did not modify the association between maternal SSRI-use during pregnancy and severe CHD.

CONCLUSION

This study, which is based on data with high case ascertainment, suggests that maternal use of SSRIs during first trimester increases the risk of severe CHD, but does not support findings from previous studies, based on administrative register data, regarding an increased risk of septal defects. The study was unable to document an interaction between socioeconomic status and maternal SSRI-use on the risk of severe CHD.

Major congenital anomalies in a Danish region

INTRODUCTION

This study describes the prevalence of congenital anomalies and changes over time in birth outcome, mortality and chronic maternal diseases.

MATERIAL AND METHODS

This study was based on population data from the EUROCAT registry covering the Funen County, Denmark, 1995-2008. The registry covers live births, foetal deaths with a gestational age (GA) of 20 weeks or more, and terminations of pregnancy due to congenital anomalies (TOPFA).

RESULTS

The overall prevalence of congenital anomalies was 2.70% (95% confidence interval: 2.58-2.80). The majority of cases had an isolated congenital anomaly, 13.9% had a chromosomal anomaly and 7.7% were multiple congenital anomalies. The combined foetal and infant mortality in the study area was 11.6 per 1,000 births. 19% (2.2 per 1,000) of these deaths were foetuses and infants with major congenital anomalies. Combined foetal and infant mortality decreased significantly over time for cases with major congenital anomalies (p < 0.001), whereas the number and proportion of TOPFA increased. Median GA at TOPFA decreased from 18 to 15 weeks. Among the congenital anomaly cases, 8% had a registration of one of these chronic maternal diseases: diabetes, epilepsy, mental disorder, thyroid disease, asthma, or inflammatory bowel disease. Medication for these conditions accounted for 46% of maternal drug use.

CONCLUSION

Maternal morbidity and use of potentially teratogenic medication have increased among congenital anomaly cases. Foetal and infant mortality for congenital anomaly cases have decreased significantly, probably owing to an increase in early prenatal diagnosis and TOPFA.

FUNDING

The study was funded by Region of South Denmark.

TRIAL REGISTRATION

not relevant.

Helminth infection does not reduce risk for chronic inflammatory disease in a population-based cohort study

BACKGROUND & AIMS

Parasitic helminth infections can suppress symptoms of allergy, type 1 diabetes, arthritis, and inflammatory bowel disease in animal models. We analyzed data from a large, population-based cohort study to determine whether common childhood enterobiasis protects against these diseases.

METHODS

We collected information on individual prescriptions filled for the drug mebendazole against Enterobius vermicularis for all children born in Denmark 1995-2008 from the National Register of Medicinal Product Statistics (n = 924,749; age 0-14 years); 132,383 of these children (14%) filled a prescription for mebendazole, 102,482 of the children (11%) had a household peer who was registered with a filled mebendazole prescription, and the remaining 689,884 children (75%) comprised the reference group. Children diagnosed with asthma, type 1 diabetes, juvenile arthritis, ulcerative colitis, or Crohn's disease were identified from the National Patient Registry. We used Poisson regression to estimate confounder-adjusted incidence rate ratios for first in- or outpatient hospital diagnosis of chronic inflammatory disease according to history of mebendazole treatment prescribed to children in the study.

RESULTS

Chronic inflammatory disease was diagnosed in 10,352 children during 6.4 million person-years of follow-up. The incidence rate ratios was 1.07 for asthma (95% confidence interval [CI]: 1.00-1.13), 1.05 for type 1 diabetes (95% CI: 0.79-1.12), 1.13 for juvenile arthritis (95% CI: 0.94-1.37), 0.77 for ulcerative colitis (95% CI: 0.41-1.46), and 1.44 for Crohn's disease (95% CI: 0.82-2.53). Results were not modified by number of treatments or age at treatment.

CONCLUSIONS

Based on a population-based analysis, enterobiasis does not reduce risk for asthma, type 1 diabetes, arthritis, or inflammatory bowel disease.

Socio-demographic factors, reproductive history and risk of osteoarthritis in a cohort of 4.6 million Danish women and men

OBJECTIVE

Studies addressing possible socio-demographic and reproductive factors in the aetiology of osteoarthritis (OA) are few. We studied possible influences of educational level, household income, marital status and parenting patterns on OA risk overall and at anatomical sites.

METHOD

We linked national register data about socio-demographic variables, reproductive histories and OA hospital contacts to a cohort of 4.6 million Danes. Ratios of first OA hospitalisation rates (RRs) were calculated using Poisson regression.

RESULTS

Overall, 100,437 women and 92,020 men had a first OA hospital contact during 91.5 million person-years between 1982 and 2008. Short education, low income and married status were significantly associated with increased OA risk, and persons with children were at higher risk of OA(overall) (RR=1.10 in women; RR=1.22 in men), OA(knee) (RRs 1.14; 1.28), OA(back) (RRs 1.18; 1.33), and OA(hand) (RRs 1.21; 1.43), but not of OA(hip) (RRs 0.96; 1.00) than persons without children. The RR of OA(overall) increased by a factor of 1.05 in women and 1.04 in men per additional child, most notably for OA(knee) in women (1.10 per child).

CONCLUSION

Risk of OA hospitalisation was highest among married persons and persons with short education or low income. The similar or even stronger associations with reproductive factors in men than women suggest that unmeasured lifestyle factors rather than biological factors associated with pregnancy might explain the higher OA risk in persons with children. However, the particularly strong association between parity and risk of OA(knee) in women is compatible with a role of pregnancy-associated factors.

Prenatal stress and risk of infectious diseases in offspring

Animal studies have suggested that prenatal stress could affect the immune system of the offspring. In a nation-wide cohort of all Danish children born from 1977 to 2004, the authors examined the association between prenatal stress, defined as maternal exposure to a stressful life event during pregnancy or in the 3-year period before conception, and the risk of severe or less severe infectious disease hospitalization in childhood. Log-linear Poisson regression models provided estimates of rate ratios. Compared with nonexposed children, children exposed prenatally to stress had a 25% (rate ratio (RR) = 1.25, 95% confidence interval (CI): 1.06, 1.47) and a 31% (RR = 1.31, 95% CI: 1.27, 1.35) increased risk of being hospitalized with a severe or a less severe infectious disease, respectively. Children born to mothers exposed to a stressful life event during pregnancy, during the 11 months before, or during the 12-35 months before conception were at 71% (RR = 1.71, 95% CI: 1.20, 2.45), 42% (RR = 1.42, 95% CI: 1.13, 1.78), and no increased (RR = 0.86, 95% CI: 0.63, 1.18) risk of severe infectious disease hospitalization. No obvious association between risk of less severe infectious disease hospitalization and timing of maternal exposure was observed. Although the authors could not determine whether this is a biologic effect of prenatal stress or an effect of other factors related indirectly to a stressful life event, their results add new information about the consequences of prenatal stress.

False-negative cerebral radionuclide flow study, in brain death, caused by a ventricular drain

A radionuclide cerebral blood flow study demonstrated normal flow in the face of clinical and electrical brain death in a patient who had a ventricular drain. After the drain became obstructed and was removed, a further radionuclide study demonstrated no flow, confirming the role of the drain in the earlier false-negative studies.