Overweight in childhood and consumer purchases in a Danish cohort.

BACKGROUND: Prevention and management of childhood overweight involves the entire family. We aimed to investigate purchase patterns in households with at least one member with overweight in childhood by describing expenditure on different food groups. METHODS: This Danish register-based cohort study included households where at least one member donated receipts concerning consumers purchases in 2019-2021 and at least one member had their Body mass index (BMI) measured in childhood within ten years prior to first purchase. A probability index model was used to evaluate differences in proportion expenditure spent on specific food groups. RESULTS: We identified 737 households that included a member who had a BMI measurement in childhood, 220 with overweight and 517 with underweight or normal weight (reference households). Adjusting for education, income, family type, and urbanization, households with a member who had a BMI classified as overweight in childhood had statistically significant higher probability of spending a larger proportion of expenditure on ready meals 56.29% (95% CI: 51.70;60.78) and sugary drinks 55.98% (95% CI: 51.63;60.23). Conversely, they had a statistically significant lower probability of spending a larger proportion expenditure on vegetables 38.44% (95% CI: 34.09;42.99), compared to the reference households. CONCLUSION: Households with a member with BMI classified as overweight in childhood spent more on unhealthy foods and less on vegetables, compared to the reference households. This study highlights the need for household/family-oriented nutrition education and intervention.

Preterm children born below 33-35 weeks of gestation have an increased risk of mathematical difficulties.

AIM: To investigate the association between gestational age (GA) and grade point averages by domains of language and mathematics at the end of lower secondary education. METHODS: A nationwide register-based study including all Danish children born in 1992-1997 who completed lower secondary education. Grades were evaluated by GA. Domain-specific differences in grades were investigated, and academic profiles were made. RESULTS: The study population comprised 319 796 children. For language, only minor differences in grades were observed. The grades in mathematics ranged from 7.02 (95% confidence interval [CI]: 7.00-7.04) at GA = 40 weeks to 5.86 (95% CI: 5.61-6.11) at GA <28 weeks. Grade differences showed lower grades in mathematics, compared to language, below GA 33-35 weeks. The academic profile of mathematical difficulties was more prevalent among GA <32 weeks. Average/high grades within both domains represented the predominant academic profile, constituting 68.8% at GA 39-41 weeks and 56.6% at GA <28 weeks. CONCLUSION: Only in mathematics decreasing GA was associated with lower grades. Increased mathematical difficulties were found below GA 33-35 weeks. The academic profile of mathematical difficulties was more prevalent among GA <32 weeks. However, the absolute differences in grades were small, and the predominant academic profile was average/high grades within both domains across all GA.

The Danish National Child Health Register.

Aim of the Database: The aim of the National Child Health Registry is to provide comprehensive insight into children's health and growth on a national scale by continuously monitoring the health status of Danish children. Through this effort, the registry assists the health authorities in prioritizing preventive efforts to promote better child health outcomes. Study Population: The registry includes all Danish children, however, incomplete coverage persists. Main Variables: The National Child Health Registry contains information on exposure to secondhand smoking, breastfeeding duration, and anthropometric measurements through childhood. The information in the registry is divided into three datasets: Smoking, Breastfeeding, and Measurements. Beside specific information on the three topics, all datasets include information on CPR-number, date of birth, sex, municipality, and region of residence. Database Status: The National Child Health Registry was established in 2009 and contains health information on children from all Danish municipalities, collected through routinely performed health examinations conducted by general practitioners and health nurses. Conclusion: The National Child Health Register is an asset to epidemiological and health research with nationwide information on children's health and growth in Denmark. Due to the unique Danish Civil Registration System, it is possible to link data from the National Child Health Register to information from several other national health and social registers which enables longitudinal unambiguous follow-up.

Exclusive breastfeeding: Relation to gestational age, birth weight, and early neonatal ward admission. A nationwide cohort study of children born after 35 weeks of gestation.

OBJECTIVES: Prematurity, being small for gestational age and early neonatal ward admission are the major neonatal conditions that may interfere with breastfeeding supportive practices in infants born at gestational age ≥35+0 weeks. We aimed to investigate the associations between gestational age, small for gestational age, early neonatal ward admission and exclusive breastfeeding at one and four months. METHODS: A register-based cohort-study of all Danish singletons with gestational age ≥35+0 weeks born in 2014-2015. In Denmark, health visitors routinely conduct free home visits throughout infants' first year and thereby report breastfeeding data to The Danish National Child Health Register. These data were linked with data from other national registers. Logistic regression models estimated the odds ratio for exclusive breastfeeding at one and four months, adjusted for confounding variables. RESULTS: The study population comprised 106,670 infants. Compared to gestational age 40 weeks, the adjusted odds ratio for exclusive breastfeeding at one month showed a decreasing tendency from gestational age ≥42 (n = 2,282) (1.07; 95% confidence interval (CI) 0.97-1.17) to 36 weeks (n = 2,062) (0.80; 95% CI 0.73-0.88). Small for gestational age (n = 2,342) was associated with decreased adjusted odds ratio for exclusive breastfeeding at one month (0.84; 95% CI 0.77-0.92). Neonatal ward admission was associated with increased adjusted odds ratio for exclusive breastfeeding at one month among late preterm infants (gestational age 35-36 weeks; n = 3,139) (1.31; 95% CI 1.12-1.54), as opposed to among early term (gestational age 37-38 weeks; n = 19,171) (0.84; 95% CI 0.77-0.92) and term infants (gestational age >38 weeks; n = 84,360) (0.89; 95% CI 0.83-0.94). The associations seemed to persist at four months. CONCLUSIONS: Decreasing gestational age and small for gestational age were associated with decreased exclusive breastfeeding rates. Neonatal ward admission was associated with increased exclusive breastfeeding rates among late preterm infants, whereas the opposite was observed among early term and term infants.

Children in Denmark with cerebral palsy rarely complete elementary school.

AIM: To investigate how children with cerebral palsy (CP) perform in the Danish school system and which factors are associated with school performance. METHOD: This was a population-based cohort study including 463 126 children born from 1997 to 2003. Data were extracted from seven national registries. The study encompassed 818 children with CP (483 [59.0%] males, 335 [41.0%] females) and 417 731 without CP (214 535 [51.4%] males, 203 196 [48.6%] females). We evaluated two primary outcomes: not completing 10 years of elementary school, defined as attending fewer than eight final mandatory exams; and grade point averages (GPAs). Mann-Whitney U tests were used to analyse differences in GPAs and logistic regressions were used to calculate odds ratios (ORs). RESULTS: Among children with and without CP, 62.6% and 12.4% did not complete elementary school respectively (OR = 11.85 [10.28-13.66]). Additionally, children with CP who attended all final exams achieved lower overall GPAs than children without CP (6.6 vs 7.3, p = 0.001). In children with CP, comorbidities, maternal education, severity of motor impairments, and intellectual deficits were associated with increased odds of not completing elementary school. Notably, one-third of children with CP with apparent normal intelligence did not complete school, despite special educational measures. INTERPRETATION: Danish children with CP rarely complete elementary school despite initiatives for a more supportive educational system. The complexity of individual needs in children with CP may be challenging for an inclusive school environment. WHAT THIS PAPER ADDS: Children with cerebral palsy (CP) have a high risk of not completing elementary school. Children with CP achieve lower overall grades than children without CP. Motor impairment, comorbidities, and maternal education are associated with poor school performance. Intellectual impairment is the most important predictor of poor school performance.

Socioeconomic outcomes beyond 30 years of age in a cohort born with very low birth weight.

AIM: As survival of infants born prematurely has increased dramatically, questions on long-term consequences have emerged. Our aim was to investigate long-term effects of very low birth weight on socioeconomic outcomes. METHODS: One hundred and fifty very low birth weight infants (VLBW) born from 1980 to 1982 at Rigshospitalet, Denmark, who had previously been followed up at age 2, 4 and 18 years, were compared to cohorts of low birth weight, normal birth weight (NBW) and a national population-based reference cohort. From the Danish national registers we obtained data regarding educational level, financial independence and living arrangements. In addition, we used the previously published results from the three cohorts. RESULTS: The VLBW cohort had lower intelligence quotient and higher risk of significant school difficulties evaluated at age 4 and 18 years. When compared to the NBW cohort, at 30-36 years of age the VLBW cohort tended to have lower educational level, OR 1.7, 95% CI 0.8-3.9, were not financially independent OR 1.5, 95% CI 0.6-3.7, lived alone OR 2.0, 95% CI 1.0-3.8 and had higher rates of the combination of all three outcomes, OR 3.2, 95% CI 0.7-15.8. CONCLUSIONS: We found trends towards poor socioeconomic outcomes in young adults born with VLBW. The relative disadvantages appeared smaller than that in childhood.

The effect of gestational age on major neurodevelopmental disorders in preterm infants.

BACKGROUND: Preterm infants have an increased risk of neurodevelopmental disorders. We established a direct quantitative comparison of the association between the degree of prematurity and three different neurodevelopmental disorders. METHODS: In this cohort study, we combined data from 995,498 children in the Danish Medical Birth Register, from birth years 1997-2013, with information on cerebral palsy, epilepsy, and special educational needs. We estimated the gestational week-specific prevalence and risk for each of the disorders. RESULTS: The risk ratio of cerebral palsy at gestational weeks 21-24, compared to term birth, was more than ten times higher than for the two other disorders. The prevalence of epilepsy and special educational needs declined almost parallel, with 9.2% (4.6%-13.5%) and 12.5% (11.2%-13.7%), respectively, per week of gestation toward term birth. Cerebral palsy did not decline similarly: from gestational weeks 21-24 until week 29 the prevalence declined insignificantly by 0.6% (-11.1%-11.0%) per week; whereas from week 29 until term, the prevalence declined markedly by 36.7% (25.9%-45.9%) per week. CONCLUSIONS: The prevalence and risk of cerebral palsy are affected differently by the degree of prematurity compared with epilepsy and special educational needs, possibly reflecting important differences in cerebral pathophysiology. IMPACT: For each week of gestation toward term birth, there was a clear log-linear decline in the prevalence of early childhood epilepsy and special educational needs. In contrast, the risk of cerebral palsy was high at the earliest gestational age, and the prevalence did not decline significantly until gestational week 29, from where it declined notably by nearly 40% for each week of gestation until term birth. Our results indicate important differences in the pathophysiological processes that associate preterm birth with these three neurodevelopmental disorders.

Academic Performance in Adolescents Born to Mothers With Gestational Diabetes-A National Danish Cohort Study.

CONTEXT: The prevalence of gestational diabetes mellitus (GDM) is increasing, and intrauterine hyperglycemia is suspected to affect offspring cognitive function. OBJECTIVE: We assessed academic performance by grade point average (GPA) in children aged 15 to 16 years at compulsory school graduation, comparing offspring exposed to GDM (O-GDM) with offspring from the background population (O-BP). METHODS: This register-based, cohort study comprised all singletons born in Denmark between 1994 and 2001 (O-GDM: n = 4286; O-BP: n = 501 045). Standardized and internationally comparable GPAs were compared in univariate and multivariable linear models. Main outcome measures included the adjusted mean difference in GPA. We also analyzed the probability of having a high GPA, a GPA below passing, and no GPA registered. RESULTS: O-GDM had a GPA of 6.29 (SD 2.52), whereas O-BP had a GPA of 6.78 (SD 2.50). The adjusted mean difference was -0.36 (95% CI, -0.44 to -0.29), corresponding to a Cohen's D of 0.14. O-GDM had a lower probability of obtaining a high GPA (adjusted odds ratio [aOR] 0.68; 95% CI, 0.59 to 0.79), while their risk of obtaining a GPA below passing was similar to O-BP (aOR 1.20; 95% CI, 0.96 to 1.50). O-GDM had a higher risk of not having a GPA registered (aOR 1.38; 95% CI, 1.24 to 1.53). CONCLUSION: Academic performance in O-GDM was marginally lower than in O-BP. However, this difference is unlikely to be of clinical importance.

[Health-related register-based research in Denmark].

Danish researchers have a unique possibility for producing high-quality observational studies through the Danish registers. The intention of this review is to provide an introduction to data sources, access and linkage of the Danish registers, primarily from Statistics Denmark, the Danish Health Data Authority and the Danish clinical quality databases. Authorisation to data access is given by each institution separately and requires permission by the Danish Data Protection Agency. Data can be linked by the unique Central Person Registry number. Known limitations and possibilities are discussed.

Low gestational age at birth and difficulties in school-A matter of 'dose'.

OBJECTIVES: Several studies suggest a relationship between gestational age at birth and risk of school difficulties. Our study aimed to investigate the association between the entire range of gestational ages and significant school difficulties measured as 1) More than nine hours per week special educational support and 2) Failing to complete compulsory school. METHODS: A population-based register study including all children attending the Danish compulsory school in 2015/2016 and all live-born infants born in Denmark from 1992 to 1997. Data were collected and linked using multiple registers held by Statistic Denmark. Multiple logistic regression analyses were used to estimate the association between gestational age and significant school difficulties, adjusted for explanatory variables. RESULTS: For measurement 1) "Special educational support" 615,789 children entered the analyses after exclusion of those with missing neonatal data. The risk of special educational support increased gradually across the entire range of gestation from 40 to ≤24 weeks: The adjusted odds ratio was 1.07 (95% confidence interval 1.03-1.12) at 39 weeks of gestational and 6.18 (95% confidence interval 5.17-7.39) at gestational ages < 28 weeks. For measurement 2) "Failing to complete compulsory school" the cohort consisted of 374,798 children after exclusion of those who died, had emigrated and/or had missing neonatal data. The risk of failing to complete compulsory school increased across the entire range of gestational ages: The adjusted odds ratio was 1.07 (95% confidence interval 1.04-1.10) at 39 weeks of gestation and 2.99 (95% confidence interval 2.41-3.71) at gestational ages < 28 weeks. In both sets of analyses GA = 40 weeks was used as reference. CONCLUSIONS: We confirm a clear association between the degree of prematurity and significant school difficulties across the entire range of gestational ages from ≤ 24 to 40 weeks.

Surfactant Need by Gestation for Very Preterm Babies Initiated on Early Nasal CPAP: A Danish Observational Multicentre Study of 6,628 Infants Born 2000-2013.

BACKGROUND: In recent years, early nasal continuous positive airway pressure (nCPAP) as respiratory support for preterm infants is being advocated as an alternative to prophylactic surfactant and treatment with mechanical ventilation. A number of infants treated with early nCPAP do not need treatment with surfactant, but few studies provide data on this. Since the 1990s, the first approach to respiratory support to preterm infants in Denmark has been early nCPAP combined with surfactant administration by the INSURE method by which the infant is intubated and surfactant administration is followed by rapid extubation to nCPAP if possible. OBJECTIVES: To investigate how often surfactant was administered in preterm infants with a gestational age below 34 weeks treated with early nCPAP as a first approach to respiratory support. METHODS: An observational multicentre study including all inborn infants with a gestational age below 34 weeks admitted to 1 of the 4 level 3 neonatal intensive care units in Denmark in the period from 2000 to 2013. RESULTS: A total of 6,628 infants were included in this study. We found that surfactant was administered in 1,056 of 1,799 (59%; 95% CI: 57-61%), in 821 of 2,864 (29%; 95% CI: 27-31%), and in 132 of 1,796 (7%; 95% CI: 6-8%) of the infants with a gestational age from 24 to 27, 28 to 31, and 32 to 33 weeks and 6 days, respectively. CONCLUSIONS: A large proportion of preterm infants treated with early nCPAP as the first approach to respiratory support was never treated with surfactant.