Our aim in this study was to analyze the importance of childbearing for risk of inflammatory bowel disease. Using data from the Norwegian Population Register and the Norwegian Patient Register, we fitted discrete-time hazard models for diagnosis of Crohn disease (CD) or ulcerative colitis (UC) among men and women aged 18-81 years in 2011-2016. Year and various sociodemographic factors were controlled for. The data included 4,304 CD cases and 8,866 UC cases. Women whose youngest child was =4 years of age had lower CD risk the following year than childless women (odds ratio (OR) = 0.73, 95% confidence interval (CI): 0.62, 0.86). There was no such reduction in CD risk among fathers. Men whose youngest child was aged =20 years had higher risks of CD (OR = 1.22, 95% CI: 1.01, 1.49) and UC (OR = 1.15, 95% CI: 1.02, 1.30) than childless men. UC risk was also increased among men whose youngest child was aged =4 years (OR = 1.14, 95% CI: 1.02, 1.27). The short-term reduction in women's CD risk after a birth may reflect biological effects of pregnancy. Alternatively, it may reflect residual confounding or lifestyle effects of parenthood that are of special relevance for CD in women. In particular, differences in use of oral contraceptives (which it was not possible to control for) may have contributed to the observed pattern.
In most societies, women at age 39 with higher levels of education have fewer children. To understand this association, we investigated the effects of childbearing on educational attainment and the effects of education on fertility in the 1964 birth cohort of Norwegian women. Using detailed annual data from ages 17 to 39, we estimated the probabilities of an additional birth, a change in educational level, and enrollment in the coming year, conditional on fertility history, educational level, and enrollment history at the beginning of each year. A simple model reproduced a declining gradient of children ever born with increasing educational level at age 39. When a counterfactual simulation assumed no effects of childbearing on educational progression or enrollment (without changing the estimated effects of education on childbearing), the simulated number of children ever born decreased very little with increasing completed educational level, contrary to data. However, when another counterfactual simulation assumed no effects of current educational level and enrollment on childbearing (without changing the estimated effects of childbearing on education), the simulated number of children ever born decreased with increasing completed educational level nearly as much as the decrease in the data. In summary, in these Norwegian data, childbearing impeded education much more than education impeded childbearing. These results suggest that women with advanced degrees have lower completed fertility on the average principally because women who have one or more children early are more likely to leave or not enter long educational tracks and never attain a high educational level.
The child-care and fertility hypothesis has been in the literature for a long time and is straightforward: As child care becomes more available, affordable, and acceptable, the antinatalist effects of increased female educational attainment and work opportunities decrease. As an increasing number of countries express concern about low fertility, the child-care and fertility hypothesis takes on increased importance. Yet data and statistical limitations have heretofore limited empirical tests of the hypothesis. Using rich longitudinal data and appropriate statistical methodology, We show that increased availability of child care increases completed fertility. Moreover, this positive effect of child-care availability is found at every parity transition. We discuss the generalizability of these results to other settings and their broader importance for understanding variation and trends in low fertility.
Models for all-cause mortality among 45,000 men and women with cancer in 12 different sites were estimated, using register and census data for complete Norwegian birth cohorts. This observed-survival method appeared to be an adequate approach. The results support the idea that women who were pregnant shortly before a breast cancer diagnosis may have a poorer prognosis than others. In principle, such an effect may also reflect that these women have a young child during the follow-up period and are burdened by that. However, this social explanation can hardly be very important, given the absence of a corresponding significant effect in men and for other cancer sites in women. Breast cancer is different from other malignancies also with respect to the effect of parenthood more generally, regardless of the timing of the pregnancies. On the whole, male and female cancer patients with children experience lower mortality than the childless, though without a special advantage associated with adult children. This suggests a social effect, perhaps operating through a link between parenthood, lifestyle and general health. No parity effect was seen for breast cancer, however, which may signal that the social effect is set off against an adverse physiologic effect of motherhood for this particular cancer. Among men, both marriage and parenthood were associated with a good prognosis. Married male cancer patients with children had mortality one-third lower than that among the childless and never-married. Women who had never married did not have the same disadvantage.
This study aimed to assess whether children's age at their parents' divorce is associated with depression in early and mid-adulthood, as indicated by medication purchase. A sibling comparison method was used to control for unobserved factors shared between siblings. The data were extracted from the Norwegian Population Register and Norwegian Prescription Database and included about 181,000 individuals aged 20-44 who had experienced parental divorce and 636,000 who had not. Controlling for age in 2004, sex, and birth order, children who were aged 15-19 when their parents divorced were 12 per cent less likely to purchase antidepressants as adults in 2004-08 than those experiencing the divorce aged 0-4. The corresponding reduction for those aged 20+ at the time of divorce was 19 per cent. However, the association between age at parental divorce and antidepressant purchases was only evident among women and those whose mothers had low education.
What are the socio-demographic characteristics of families in Norway who have children after assisted reproductive technology (ART), and have these characteristics changed over time?
Parents who conceive through ART in Norway tend to be advantaged families, and their socio-demographic profile has not changed considerably over the period 1985-2014.
A small number of studies show that couples who conceive through ART tend to be socio-economically advantaged.
Norwegian Population Register, the Medical Birth Register and the national data bases were linked to study all live births in Norway between 1985 and 2014.
The sample consisted of 1?757?768 live births. Simple bivariate analyses were performed to describe the socio-demographic characteristics of parents who conceived through ART and changes in these characteristics over the time period 1985-2014. We used linear probability models to estimate the association between parental income and giving birth after ART from 2000 to 2014, before and after adjustment for maternal age at delivery, education and area of residence.
Parents conceiving through ART were more likely to be older, with the highest levels of income and education, and married. Their socio-demographic profiles did not change considerably during the period 1985-2014. In the unadjusted model, parents belonging to the top income quartile were 4.2 percentage points more likely (95% CI: 4.1 to 4.3) to have conceived through ART than parents who belonged to the bottom income quartile. Adjustment for maternal age only partially reduced the income disparities (for the top income quartile by 35% (ß?=?2.7 with 95% CI: 2.5 to 2.8)). Additional adjustment for maternal education, marital status and area of residence did not further attenuate the associations.
The data does not enable us to tell whether the lower numbers of children conceived through ART amongst more disadvantaged individuals is caused by lower success rates with ART treatment, lower demand of ART services or barriers faced in access to ART. The study focuses on Norway, a context characterised by high subsidisation of ART services.
Even though in Norway access to ART services is highly subsidised, the results highlight important and persisting social inequities in use of ART. The results also indicate that children born after ART grow up in resourceful environments, which will benefit their development and well-being.
This work was supported by European Research Council agreement n. 803959 (to A.G.), by Economic and Social Research Council grant ES/M001660/1 and by the Research Council of Norway through its Centres of Excellence funding scheme, project number 262700. The authors have no conflict of interest to declare.
Diagnostic and treatment protocols for childhood cancer are generally standardized, and survival ought therefore be fairly equal across social strata in societies with free public health care readily available. This study explores whether there nevertheless are disparities in mortality after childhood cancer in Norway depending on parents' socioeconomic status. Limited knowledge on differentials exist from earlier analyses. Discrete-time hazard regression models for all-cause mortality the first ten years following diagnosis were estimated for all Norwegian children (
Multilevel discrete-time hazard models for cancer mortality in cancer patients were estimated from register and census data to find out whether hospital affiliation and municipality socio-economic resources had an impact on cancer survival in Norway in the 1990s. Affiliation to a small local hospital was a disadvantage in only one health region. There were also other differences between health regions. Most notably, those who lived in Oslo and Southern Norway had a relatively poor survival, given the size of the nearest hospital. In addition to confirming the better prognosis for patients who themselves had high education, it was found that survival improved with increasing average education. This was primarily a result of earlier diagnosis. The impact of the economic situation was less clear. While a high average income was unrelated to mortality, as opposed to the beneficial impact of high individual income, a high unemployment rate, picking up also effects of individual unemployment, had an adverse effect.
Short and very long interbirth intervals are associated with worse perinatal, infant and immediate maternal outcomes. Accumulated physiological, mental, social and economic stresses arising from raising children close in age may also mean that interbirth intervals have longer term implications for the health of mothers and fathers, but few previous studies have investigated this.
Discrete-time hazards models were estimated to analyse associations between interbirth intervals and mortality risks for the period 1980-2008 in complete cohorts of Norwegian men and women born during 1935-1968 who had had two to four children. Associations between interbirth intervals and use of medication during 2004-2008 were also analysed using ordinary least-squares regression. Covariates included age, year, education, age at first birth, parity and change in coparent since the previous birth.
Mothers and fathers of two to three children with intervals between singleton births of less than 18 months, and mothers of twins, had raised mortality risks in midlife and early old age relative to parents with interbirth intervals of 30-41 months. For parents with three or four children, longer average interbirth intervals were associated with lower mortality. Short intervals between first and second births were also positively associated with medication use. Very long intervals were not associated with raised mortality or medication use when change of coparent since the previous birth was controlled.
Closely spaced and multiple births may have adverse long-term implications for parental health. Delayed entry to parenthood and increased use of fertility treatments mean that both are increasing, making this a public health issue which needs further investigation.
Several studies have shown a positive relationship between mortality and episodes of income decline, unemployment, or poverty shortly before death or in the more distant past. Our objective was to analyse the mortality effects of earlier income changes more generally, net of the overall level. We used Norwegian register data that included individual histories of annual labour income and focused on mortality among men aged 50-69 in 1990-2002. Men in this age group who, during the preceding 15 years, had experienced at least two substantial falls in income as well as at least one substantial increase, or vice versa, experienced an excess mortality of 17 per cent. For men who experienced fewer changes, there were only weak indications of excess mortality. Variation dominated by falls in income did not have a more adverse effect than variation dominated by rises.