Evaluating causal associations of chronotype with pregnancy and perinatal outcomes and its interactions with insomnia and sleep duration: a mendelian randomization study.

Background: Observational studies suggested chronotype was associated with pregnancy and perinatal outcomes. Whether these associations are causal is unclear. Our aims are to use Mendelian randomization (MR) to explore (1) associations of evening preference with stillbirth, miscarriage, gestational diabetes, hypertensive disorders of pregnancy, perinatal depression, preterm birth and offspring birthweight; and (2) differences in associations of insomnia and sleep duration with those outcomes between chronotype preferences.

MinLinMo: a minimalist approach to variable selection and linear model prediction.

Generating prediction models from high dimensional data often result in large models with many predictors. Causal inference for such models can therefore be difficult or even impossible in practice. The stand-alone software package MinLinMo emphasizes small linear prediction models over highest possible predictability with a particular focus on including variables correlated with the outcome, minimal memory usage and speed.

Telomere length in relation to fecundability and use of assisted reproductive technologies: the Norwegian Mother, Father, and Child Cohort Study.

Background: Telomere length (TL) has been reported to be associated with conditions such as endometriosis and polycystic ovary syndrome, with some studies finding associations with shorter TL and others with longer TL. In men, studies mostly report associations between shorter TL and sperm quality. To our knowledge, no studies have thus far investigated associations between TL and fecundability or the use of assisted reproductive technologies (ART).

Lithium Use During Pregnancy in 14 Countries.

Importance: In pregnancy, the benefits of lithium treatment for relapse prevention in psychiatric conditions must be weighed against potential teratogenic effects. Currently, there is a paucity of information on how and when lithium is used by pregnant women.

Objective: To examine lithium use in the perinatal period.

Preterm birth in assisted reproduction: the mediating role of hypertensive disorders in pregnancy.

Study Question: To what extent can hypertensive disorders in pregnancy (HDP) explain the higher risk of preterm birth following frozen embryo transfer (frozen-ET) and fresh embryo transfer (fresh-ET) in ART compared with naturally conceived pregnancies?

Summary Answer: HDP did not contribute to the higher risk of preterm birth in pregnancies after fresh-ET but mediated 20.7% of the association between frozen-ET and preterm birth.

What Is Known Already: Risk of preterm birth is higher after ART compared to natural conception.

The temporal alignment of mental health consultations across family members: a study of Norwegian adolescents, their parents, and siblings.

Purpose: Mental health problems among adolescents have become more prevalent in recent years. Parents' and siblings' mental health might be affected by living with a depressed adolescent. This study examines how the mental health of family members develops in the years before and after an adolescent seeks help for depression.

Non-random mating patterns within and across education and mental and somatic health.

Partners resemble each other in health and education, but studies usually examine one trait at a time in established couples. Using data from all Norwegian first-time parents (N = 187,926) between 2016-2020, we analyse grade point average at age 16, educational attainment, and medical records of 10 mental and 10 somatic health conditions measured 10 to 5 years before childbirth. We find stronger partner similarity in mental (median r = 0.

Mass cytometry reveals cellular correlates of immune response heterogeneity to SARS-CoV-2 vaccination in the elderly.

Heterogeneity in vaccine response, particularly in vulnerable populations like the elderly, represents a significant public health challenge. We conducted an in-depth examination of immune cell profiles before and after SARS-CoV-2 vaccination utilizing mass cytometry in a cohort of healthy Norwegian seniors (65-80 years). We have demonstrated that higher pre-vaccination frequencies of CD27IgD class-switched memory B cells and subsets of CD27CD24CD38 transitional B cells were associated with a robust vaccine response.

Caesarean section and risk of infection in offspring: systematic review and meta-analysis of observational studies.

Objective: To compare the risk of hospital admissions with infections and infections not in hospital in children born by caesarean section with children born by vaginal birth.

Data Sources: Medline, Embase, and PubMed were searched with no restriction on start date up to 12 February 2024.

Study Selection: Observational studies were included that reported the association between caesarean section and vaginal birth in relation to the risk of infections (both those that lead to hospital admission and those that do not) up to 18 years of age.

School Starting Age, Fertility, and Family Formation: Evidence From the School Entry Cutoff Using Exact Date of Birth.

In the past 50 years, the age at first birth in Norway and other European countries has shifted, leading to concerns that individuals begin childbearing too late to reach their intended family size. This article analyzes the effect of school starting age on fertility and family formation by utilizing Norway's age-based school entry policy. Using individual-level register data and a regression discontinuity design, we find that being born after the age cutoff for school start results in an increased age at first birth of 2.

Parental epigenetic age acceleration and risk of adverse birth outcomes: the Norwegian mother, father and child cohort study.

Background: Few studies have examined associations between maternal epigenetic age acceleration and adverse birth outcomes, and none have investigated paternal epigenetic age acceleration. Our objective was to assess the associations of parental (both maternal and paternal) epigenetic age acceleration in relation to birth outcomes.

Methods: Parental epigenetic age was estimated using seven established epigenetic clocks in 2198 mothers and 2193 fathers from the Norwegian Mother, Father, and Child Cohort Study (MoBa).

Environmental exposures and fecundability: The Norwegian Mother, Father, and Child Cohort study.

Previous studies have linked certain environmental exposures to reduced fecundability, influencing exposure recommendations. We continue to encounter numerous environmental exposures in our everyday lives, and further evidence is needed regarding their effects on fecundability. We evaluated associations between various self-reported environmental exposures and fecundability, measured as time to pregnancy, in 64,942 women and 53,219 men participating in the Norwegian Mother, Father, and Child Cohort study (MoBa).

School performance and the social gradient in young adult death in Norway.

Young adults from low socioeconomic backgrounds face an increased risk of early mortality. Here we utilize population-wide data from 17 Norwegian birth cohorts (N = 986,573) to assess whether this risk gradient was explained by early-life educational performance, specifically grade point average at 16 years of age. We show that the gradients in both parental education and income largely disappeared when adjusting for school performance in the models.

Co-occurrence between mental disorders and physical diseases: a study of nationwide primary-care medical records.

Background: Mental disorders and physical-health conditions frequently co-occur, impacting treatment outcomes. While most prior research has focused on single pairs of mental disorders and physical-health conditions, this study explores broader associations between multiple mental disorders and physical-health conditions.

Methods: Using the Norwegian primary-care register, this population-based cohort study encompassed all 2 203 553 patients born in Norway from January 1945 through December 1984, who were full-time residents from January 2006 until December 2019 (14 years; 363 million person-months).

Covid-19 vaccination and menstrual bleeding disturbances among women of fertile age: a Norwegian registry study.

This study evaluated the relationship between Covid-19 vaccination and menstrual bleeding disturbances using a large national registry linkage including 666,467 women between 20 and 40 years of age residing in Norway on January 1st, 2019. Information on vaccination-BNT162b2 and mRNA-1273 - was obtained from the Norwegian vaccination registry. Diagnoses of menstrual disturbances (absent/scanty, excessive, irregular/frequent menstruation, and intermenstrual bleeding) was obtained from the general practitioner database.

Epigenome-wide analysis across the development span of pediatric acute lymphoblastic leukemia: backtracking to birth.

Background: Cancer is the leading cause of disease-related mortality in children. Causes of leukemia, the most common form, are largely unknown. Growing evidence points to an origin in-utero, when global redistribution of DNA methylation occurs driving tissue differentiation.

Pregnancy-Associated Maternal Mortality Within One Year After Childbirth: Population-Based Cohort Study.

Objective: The objective of this study is to assess associations between pregnancy complications and pregnancy-associated maternal mortality (PAM) within 1 year after childbirth.

Design: Population-based cohort study.

Setting: Norway, 1967-2020.

A nationwide analysis of 350 million patient encounters reveals a high volume of mental-health conditions in primary care.

How many primary-care encounters are devoted to mental-health conditions compared with physical-health conditions? Here we analyzed Norway's nationwide administrative primary-care records, extracting all doctor-patient encounters occurring during 14 years (2006-2019) for the population aged 0-100 years. Encounters were recorded according to the International Classification of Primary Care. We compared the volume of mental-health encounters against volumes for conditions in multiple different body systems.