Maternal use of hormonal contraception and risk of childhood leukemia: A Scandinavian population-based cohort study.

Background: Maternal hormonal contraception use has been associated with childhood leukemia risk. However, studies are few and often based on self-reported information.

Methods: Using registry data from Denmark, Norway, and Sweden, we identified 3,183,316 children (born 1996-2018) and followed them from birth until leukemia diagnosis, censoring (death, emigration, other cancer, 20th birthday) or study closure (December 31st, 2017, 2018 or 2020).

Risk of borderline ovarian tumors after fertility treatment - Results from a Danish cohort of infertile women.

Objective: Results from previous studies examining the association between fertility treatment and borderline ovarian tumors are inconsistent. The aim of this study was to investigate the association between fertility treatment and borderline ovarian tumors in a cohort of infertile women.

Methods: This cohort study was based on the Danish Infertility Cohort and included all infertile women aged 20-45 years living in Denmark between 1 January 1995 and 31 December 2017 (n = 146,891).

Maternal use of hormonal contraception and risk of childhood autism spectrum disorders: A Parental Exposures and Child Health (PECH) cohort study.

A recent hypothesis suggests that maternal hormonal contraception use has contributed to the increasing incidence of autism spectrum disorders (ASD). We used a nationwide population-based cohort (the PECH cohort) including 1,056,149 Danish children born in the period January 1, 1998, to December 31, 2014, to assess associations between maternal hormonal contraception use and childhood ASD (end of follow-up: December 31, 2017). Maternal hormonal contraception use was grouped as "recent use" (≤ 3 months before pregnancy start or during pregnancy), "previous use" (>3 months before pregnancy start) and "never use", except for few products.

In Utero Exposure to Hormonal Contraception and Mortality in Offspring with and without Cancer: A Nationwide Cohort Study.

Approximately 400 million women of reproductive age use hormonal contraceptives worldwide. Eventually, pregnancy sometimes occurs due to irregular use. Use in early pregnancy is found to be associated with child morbidities including cancer, the main reason for disease-related death in children.

Effects of early maternal cancer and fertility treatment on the risk of adverse birth outcomes.

Background: Early maternal cancer and fertility treatment each increase the risk for adverse birth outcomes, but the joint effect of these outcomes has not yet been reported. Thus, the aim was to assess the individual and joint effect of maternal cancer and fertility treatment on the risk for adverse birth outcomes.

Methods: This population-based cohort study included 5487 live-born singletons identified in the Danish Medical Birth Register (1994-2016) of mothers with previous cancer (<40 years) recorded in the Danish Cancer Registry (1955-2014).

Association Between Maternal Hormonal Contraception Use and Central Nervous System Tumors in Children.

Importance: The incidence of central nervous system (CNS) tumors in children appears to be increasing, yet few risk factors are established. There is limited information regarding whether maternal hormonal contraception use increases this risk.

Objective: To examine the association between maternal hormonal contraception use and CNS tumors in children (<20 years).

Prenatal exposure to nitrofurantoin and risk of childhood leukaemia: a registry-based cohort study in four Nordic countries.

Background: Studies have suggested increased risks of childhood leukaemia after prenatal exposure to antibiotics, particularly nitrofurantoin. However, these findings may be related to the underlying maternal infection. This multinational study aimed to investigate the association between prenatal nitrofurantoin exposure and childhood leukaemia while accounting for maternal infection.

Hospital Contacts for Psychiatric Disorders in Parents of Children With Cancer in Denmark.

Background: Having a child diagnosed with cancer is a devastating experience that may affect parents' mental health. We aimed to assess the risk of hospital contacts for psychiatric disorders in parents of children with cancer.

Methods: We conducted a nationwide population-based cohort study using Danish registry data.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers.

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer.

Maternal use of hormonal contraception and risk of childhood ADHD: a nationwide population-based cohort study.

Although maternal use of hormones has been suspected of increasing the risk for childhood attention-deficit/hyperactivity disorder (ADHD), no study has examined hormonal contraception use in this context. We examined the association between maternal hormonal contraception use before or during pregnancy and ADHD risk in children. This nationwide population-based cohort study included 1,056,846 children born in Denmark between 1998 and 2014.

The impact of childhood cancer on parental separation, divorce, and family planning in Denmark.

Background: Childhood cancer is a devastating experience for the family. The objective of the current study was to assess the impact of having a child with cancer on parental separation, divorce, and future family planning among families residing in Denmark.

Methods: The authors conducted a nationwide cohort study using Danish registry data.

Ninth-grade school achievement in Danish children conceived following fertility treatment: a population-based cohort study.

Objective: To assess whether academic achievement among children conceived following fertility treatment is different from that of children born to fertile women while also considering the underlying infertility.

Design: Population-based cohort study.

Setting: Denmark.

Incidence and time trends of childhood cancer in Denmark, 1943-2014.

Surveillance of childhood cancer incidence is informative for etiologic research and health policy. However, high-quality data covering several decades of virtually complete cancer diagnosis in children is sparse. Incident cases of childhood cancer (0-19 years at diagnosis), classified according to Birch and Marsden's International Classification of Childhood Cancer, first edition (ICCC-1), were identified in the Danish Cancer Registry and used to calculate age-standardized incidence rates (ASRs) and estimated annual percentage change (EAPC) separately for 1943-1977 (early period) and 1977-2014 (recent period).

Risk of febrile seizures among children conceived following fertility treatment: A cohort study.

Background: Studies have shown that fertility treatment in mothers is associated with neurological problems in children. However, knowledge about any association between maternal use of fertility treatment and febrile seizures in children is lacking.

Objective: To determine whether maternal use of fertility treatment is associated with febrile seizures in children.

The impact of childhood cancer on parental working status and income in Denmark: Patterns over time and determinants of adverse changes.

Having a child with cancer may affect the socioeconomic situation of the parents. We aimed to assess the impact of childhood cancer on parental working status and income and to identify determinants of adverse changes after the child's cancer diagnosis by calendar period. We conducted a nationwide cohort study using Danish registry data.

Association Between Fertility Treatment and Cancer Risk in Children.

Importance: An increasing number of children worldwide are born after the use of fertility treatment, although it remains unclear whether the treatment affects the risk of childhood cancer and whether any associations observed are due to the use of specific drugs, the use of specific procedures, or the underlying infertility.

Objective: To examine the association between different types of fertility treatments and cancer risk in children.

Design, Setting, And Participants: A retrospective cohort study based on Danish population-based registry data and the Danish Infertility Cohort (individual record linkage) that included 1 085 172 children born in Denmark between January 1, 1996, and December 31, 2012, linked with parental information.

Maternal use of hormonal contraception and risk of childhood leukaemia: a nationwide, population-based cohort study.

Background: Maternal hormonal contraception has been suspected of being linked to an increased risk of childhood cancer. The aim of this study was to assess the association between maternal use of hormonal contraception and diagnosis of leukaemia in their children.

Methods: In this cohort study, we followed a nationwide cohort of 1 185 157 liveborn children between 1996 and 2014 listed in the Danish Medical Birth Registry and identified those diagnosed with leukaemia in the Danish Cancer Registry.

Coffee, tea and caffeine consumption and risk of primary infertility in women: a Danish cohort study.

Introduction: The aim of this study was to investigate whether consumption of coffee, tea and caffeine affects the risk of primary infertility in women.

Material And Methods: We selected nulliparous Danish women aged 20-29 years from a prospective cohort and retrieved information on coffee and tea consumption from a questionnaire and an interview at enrollment. We assessed the women's fertility by linkage to the Danish Infertility Cohort and retrieved information on children and vital status from the Civil Registration System.

Maternal fertility problems and risk for transient neonatal diabetes mellitus.

Aims: The study of imprinting disorders in the context of infertility and its treatment is important, as studies have indicated an increased risk. In this study, we evaluated the risk of transient neonatal diabetes mellitus (TNDM), defined here as diabetes mellitus presenting within the first six weeks of life, in children born to women with fertility problems.

Methods: This nationwide register-based cohort study comprised all 2,107,837 children born in Denmark between 1977 and 2010.