Post-COVID symptoms after SARS-CoV-2 omicron infection and the effect of booster vaccination: A population-based cohort study.

Background: The impact of vaccination on the type and risk of specific post-COVID symptoms after Omicron infection is not clear. We aimed to investigate the excess risk and patterns of 22 symptoms 3-5 months after Omicron infection, comparing uninfected and infected subjects with and without recent booster vaccination.

Methods: We conducted a population-based prospective study based on four questionnaire-based cohorts linked to national health registries.

Multi-ancestry genome-wide association study of severe pregnancy nausea and vomiting identifies risk loci associated with appetite, insulin signaling, and brain plasticity.

While most pregnancies are affected by nausea and vomiting, hyperemesis gravidarum (HG) is at the severe end of the clinical spectrum and is associated with dehydration, undernutrition, and adverse maternal, fetal, and child outcomes. Herein we performed a multi-ancestry genome-wide association study (GWAS) of severe nausea and vomiting of pregnancy of 10,974 cases and 461,461 controls across European, Asian, African, and Latino ancestries. We identified ten significantly associated loci, of which six were novel ( , , , , , and and confirmed previous genome-wide significant associations with risk genes , , , and .

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).

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.

Multi-ancestry GWAS of severe pregnancy nausea and vomiting identifies risk loci associated with appetite, insulin signaling, and brain plasticity.

While most pregnancies are affected by nausea and vomiting, hyperemesis gravidarum (HG) is at the severe end of the clinical spectrum and is associated with dehydration, undernutrition, and adverse maternal, fetal, and child outcomes. Herein we performed a multi-ancestry genome-wide association study (GWAS) of severe nausea and vomiting of pregnancy of 10,974 cases and 461,461 controls across European, Asian, African, and Latino ancestries. We identified ten significantly associated loci, of which six were novel (, , , , , and , and confirmed previous genome-wide significant associations with risk genes , , , and .

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).

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.

The association between tobacco use and COVID-19 diagnoses in three Nordic countries: a pooled analysis.

Previous research has suggested an unexpected negative association between smoking and susceptibility to COVID-19. This study, drawing on population-based data from three Nordic countries-Sweden, Norway, and Finland-aims to investigate this association further, capitalizing on diversity introduced by different containment measures. The objective of this research was to examine the association between cigarette smoking and snus (smokeless tobacco) use and the risk of confirmed COVID-19 infection.

Development and validation of a prognostic model to predict birth weight: individual participant data meta-analysis.

Objective: To predict birth weight at various potential gestational ages of delivery based on data routinely available at the first antenatal visit.

Design: Individual participant data meta-analysis.

Data Sources: Individual participant data of four cohorts (237 228 pregnancies) from the International Prediction of Pregnancy Complications (IPPIC) network dataset.

Characterization of the SARS-CoV-2 antibody landscape in Norway in the late summer of 2022: high seroprevalence in all age groups with patterns of primary Omicron infection in children and hybrid immunity in adults.

Background: According to Norwegian registries, 91% of individuals ≥ 16 years had received ≥ 1 dose of COVID-19 vaccine by mid-July 2022, whereas less than 2% of children < 12 years were vaccinated. Confirmed COVID-19 was reported for 27% of the population, but relaxation of testing lead to substantial underreporting. We have characterized the humoral immunity to SARS-CoV-2 in Norway in the late summer of 2022 by estimating the seroprevalence and identifying antibody profiles based on reactivity to Wuhan or Omicron-like viruses in a nationwide cross-sectional collection of residual sera, and validated our findings using cohort sera.

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

In women, shorter telomeres have been reported to be associated with conditions such as endometriosis and polycystic ovary syndrome, whereas other studies have reported the opposite. In men, studies mostly report associations between shorter telomeres and sperm quality. To our knowledge, no studies have thus far investigated the associations between TL and fecundability or the use of ART.

Association of common maternal infections with birth outcomes: a multinational cohort study.

Purpose: It is unclear whether common maternal infections during pregnancy are risk factors for adverse birth outcomes. We assessed the association between self-reported infections during pregnancy with preterm birth and small-for-gestational-age (SGA) in an international cohort consortium.

Methods: Data on 120,507 pregnant women were obtained from six population-based birth cohorts in Australia, Denmark, Israel, Norway, the UK and the USA.

Assessing causal links between age at menarche and adolescent mental health: a Mendelian randomisation study.

Background: The timing of puberty may have an important impact on adolescent mental health. In particular, earlier age at menarche has been associated with elevated rates of depression in adolescents. Previous research suggests that this relationship may be causal, but replication and an investigation of whether this effect extends to other mental health domains is warranted.

Placental efflux transporters and antiseizure or antidepressant medication use impact birth weight in MoBa cohort.

Low birth weight raises neonatal risks and lifelong health issues and is linked to maternal medication use during pregnancy. We examined data from the Norwegian Mother, Father, and Child Cohort Study and the Medical Birth Registry of Norway, including 69,828 offspring with genotype data and 81,189 with maternal genotype data. We identified genetic risk variants in placental efflux transporters, calculated genetic scores based on alleles related to transporter activity, and assessed their interaction with prenatal use of antiseizure or antidepressant medication on offspring birth weight.