Background The aim of pregnancy cohorts was to understand causes and development of
health and disease throughout the life course. A major challenge in cohort studies is to avoid …

A follow-up questionnaire on maternal health was distributed within the Danish National
Birth Cohort (established in 1996–2002) 14 years after the index birth. Responses were …

Loss to follow-up in cohort studies may result in biased association estimates. Of 61,895
women entering the Danish National Birth Cohort and completing the first data-collection …

Background: Participation rates in large cohort studies have decreased during the last 2
decades. The consequences of this trend for relative risk estimation are unknown. Methods …

The Norwegian Mother and Child Cohort Study (MoBa) was planned in the 1990s partly by
researchers at the Medical Birth Registry of Norway (MBRN) 1 and partly by researchers at …

Longitudinal cohort studies can provide important evidence about preventable causes of
disease, but the success relies heavily on the commitment of their participants, both at …

Background Large birth cohort studies are extremely valuable in assessing associations
between early life exposures and long‐term outcomes. Establishing new birth cohorts is …

Self‐selection in epidemiological studies may introduce selection bias and influence the
validity of study results. To evaluate potential bias due to self‐selection in a large …

Abstract The Norwegian Mother and Child Cohort Study (MoBa) is an observational,
prospective study of up to 100 000 families. The study aims to find causes of diseases, with a …

Background: It is well known that the time from conception to early childhood has importance
for health conditions that reach into later stages of life. Recent research supports this view …