Norway

This study examines how major societal changes in Norway since the 1950s have influenced the heritability of fertility behaviors, specifically age at first birth and number of children, revealing that these effects vary by gender and outcome. While a theory attributing increased heritability to weakened norms and broader opportunities is found insufficient, results partially support the idea that genetic influence grows during periods of societal transition, particularly related to the rise of dual-earner families and family policy changes. The findings underscore the need to account for societal structures and gender differences when studying genetic contributions to fertility.

This study uses harmonized register data from Denmark, Sweden, Norway, and Finland to examine trends in childbearing among female same-sex couples compared to different-sex couples following legal union, and how this varies by education and income. The findings show a sharp rise in childbearing among female same-sex couples, nearing parity with different-sex couples in Denmark, Sweden, and Norway by around 2010, while Finland showed a later and slower increase; higher education, but not income, was linked to greater likelihood of having a child. The authors attribute these shifts to legal changes and increasingly supportive cultural and normative environments that have made same-sex parenthood more attainable in the Nordic region.

This study uses data from the Norwegian Mother, Father and Child Cohort Study (MoBa) and linked registers to examine how various maternal and child health factors relate to the probability and timing of having a second or third child. Findings show that chronic health problems before or during pregnancy, temporary pregnancy-related complications, adverse birth experiences, poor postnatal physical health, and postnatal depression are generally linked to reduced probabilities of subsequent births, while chronic health problems in the most recently born child show fewer consistent associations, except for reduced fertility among mothers whose child had colic or slept little. The authors discuss possible explanations and implications of these health–fertility associations.

This study uses Norwegian register data to examine how educational enrollment and attainment contributed to the country's rapid fertility decline in the 2010s among cohorts born 1964‒2006. Using counterfactual simulation, the authors find that educational expansion only partially explained cohort fertility decline for older female cohorts (1964‒1978) and did not contribute for men or younger cohorts; instead, the broader period and cohort fertility declines, especially rising childlessness among low and medium educated groups, were driven mainly by decreased fertility within educational levels rather than by increased education itself.