Air pollution and Autism in Denmark.

Background: Previous autism spectrum disorder (ASD) and air pollution studies focused on pregnancy exposures, but another vulnerable period is immediate postnatally. Here, we examined early life exposures to air pollution from the pre- to the postnatal period and ASD/ASD subtypes in the Danish population.

Methods: With Danish registers, we conducted a nationwide case-control study of 15,387 children with ASD born 1989-2013 and 68,139 population controls matched by birth year and sex identified from the birth registry.

Pre-conceptual and prenatal supplementary folic acid and multivitamin intake, behavioral problems, and hyperkinetic disorders: A study based on the Danish National Birth Cohort (DNBC).

Objective: To evaluate whether early folic acid or multivitamin supplementation during pregnancy prevents diagnosis of hyperkinetic disorders (HKD), treatment for attention deficit hyperactivity disorder (ADHD), and ADHD-like behaviors reported by parents participating in the DNBC for children at age 7.

Methods: HKD diagnosis and ADHD medication use data were obtained from the Danish National Hospital, Central Psychiatric and Pharmaceutical registers. We estimated hazard ratios (HRs) for HKD diagnosis and ADHD medication use and risk ratios (RRs) for parent-reported ADHD behavior collected with the Strength and Difficulties Questionnaire (SDQ), comparing children whose mothers took folic acid or multivitamin supplements early in pregnancy defined as starting periconceptionally (4 weeks prior to their last menstrual period (LMP)) through 8 weeks after their LMP (4-8 weeks), to children whose mothers indicated no supplement use for the same entire period.

Maternal pre-pregnancy and gestational diabetes, obesity, gestational weight gain, and risk of cancer in young children: a population-based study in California.

Purpose: We aimed to examine the influence of pre-pregnancy diabetes, pre-pregnancy body mass index (BMI), gestational diabetes, and gestational weight gain on childhood cancer risk in offspring.

Methods: We identified cancer cases (n = 11,149) younger than age 6 years at diagnosis from the California Cancer Registry registered between 1988 and 2013. Controls (n = 270,147) were randomly sampled from California birth records, and frequency matched by year of birth to all childhood cancers during the study period.

Prenatal Use of Acetaminophen and Child IQ: A Danish Cohort Study.

Background: Acetaminophen (paracetamol) is the most commonly used pain and fever medication during pregnancy, and recently has been linked to hyperactivity and behavioral problems in children. We examine whether prenatal use of acetaminophen affects children's intelligence quotient (IQ).

Methods: We studied 1,491 mothers and children enrolled in the Danish National Birth Cohort (DNBC; 1996-2002).

Maternal use of acetaminophen during pregnancy and risk of autism spectrum disorders in childhood: A Danish national birth cohort study.

Acetaminophen (paracetamol) is the most commonly used pain and fever medication during pregnancy. Previously, a positive ecological correlation between acetaminophen use and autism spectrum disorders (ASD) has been reported but evidence from larger studies based on prospective data is lacking. We followed 64,322 children and mothers enrolled in the Danish National Birth Cohort (DNBC; 1996-2002) for average 12.

Childhood Bereavement and Type 1 Diabetes: a Danish National Register Study.

Background: Death of a close family member such as a parent or a sibling can cause prolonged stress and changes in the family structure that may have extensive social and health effects on a young child. The aim of this paper is to examine the rate of type 1 diabetes following bereavement due to death of a first-degree family member in early life.

Methods: We used data from the Danish Civil Registration System (CRS) to identify singleton births in Denmark born 1 January 1980 through 31 December 2005, n = 1 740 245 and their next of kin.

Preconceptional and prenatal supplementary folic acid and multivitamin intake and autism spectrum disorders.

Objective: To evaluate whether early folic acid supplementation during pregnancy prevents diagnosis of autism spectrum disorders in offspring.

Methods: Information on autism spectrum disorder diagnosis was obtained from the National Hospital Register and the Central Psychiatric Register. We estimated risk ratios for autism spectrum disorders for children whose mothers took folate or multivitamin supplements from 4 weeks prior from the last menstrual period through to 8 weeks after the last menstrual period (-4 to 8 weeks) by three 4-week periods.

In-utero exposure to bereavement and offspring IQ: a Danish national cohort study.

Background: Intelligence is a life-long trait that has strong influences on lifestyle, adult morbidity and life expectancy. Hence, lower cognitive abilities are therefore of public health interest. Our primary aim was to examine if prenatal bereavement measured as exposure to death of a close family member is associated with the intelligence quotient (IQ) scores at 18-years of age of adult Danish males completing a military cognitive screening examination.

Risk of childhood injuries after prenatal exposure to maternal bereavement: a Danish National Cohort Study.

Objectives: The aim of this study was to assess the risk of injuries among children exposed to a stressful life exposure (defined as bereavement) before conception or during fetal life.

Design: Population-based cohort study.

Setting: Denmark.

Prenatal exposure to bereavement and type-2 diabetes: a Danish longitudinal population based study.

Background: The etiology of type-2 diabetes is only partly known, and a possible role of prenatal stress in programming offspring for insulin resistance has been suggested by animal models. Previously, we found an association between prenatal stress and type-1 diabetes. Here we examine the association between prenatal exposure to maternal bereavement during preconception and pregnancy and development of type-2 diabetes in the off-spring.

Socio-demographic characteristics of women sustaining injuries during pregnancy: a study from the Danish National Birth Cohort.

Objectives: To describe adverse birth outcomes associated with hospital-treated injuries that took place among women in the Danish National Birth Cohort.

Design: Longitudinal cohort study.

Setting: Denmark.

Early life disease programming during the preconception and prenatal period: making the link between stressful life events and type-1 diabetes.

Background: To assess the risk of developing Type-1 diabetes among children who were exposed to maternal bereavement during the prenatal or 1-year preconception period.

Methods: We identified N = 1,548,746 singleton births born in Denmark between January 1(st) 1979 through December 31(st) 2004, and their next of kin. Altogether, 39,857 children were exposed to bereavement during their prenatal life.

[Medically-induced abortion and risk of reproductive failures in subsequent pregnancy].

A few studies indicate that a medically-induced abortion may increase the risk of reproductive failures in a subsequent pregnancy. We identified all female residents in Denmark who had an induced abortion with no medical indication from 1999 to 2004 and who later became pregnant. The study is based upon a comparison of 2710 women who had a medically-induced abortion and 9104 who had a surgically-induced abortion.

Medical abortion and the risk of subsequent adverse pregnancy outcomes.

Background: The long-term safety of surgical abortion in the first trimester is well established. Despite the increasing use of medical abortion (abortion by means of medication), limited information is available regarding the effects of this procedure on subsequent pregnancies.

Methods: We identified all women living in Denmark who had undergone an abortion for nonmedical reasons between 1999 and 2004 and obtained information regarding subsequent pregnancies from national registries.

Hand-washing and diapering equipment reduces disease among children in out-of-home child care centers.

Objective: The objective of this study was to determine whether the installation of equipment for diaper-changing, hand-washing, and food preparation that is specifically designed to reduce the transmission of infectious agents would result in a decrease in the rate of diarrheal illness among children and their teachers in child care centers.

Methods: Twenty-three pairs of child care centers were matched on size and star-rated license level. One member of each pair was randomly assigned to an intervention group and the other to a control group.