This study investigates two concurrent trends across Europe and North America: the increasing instability of parental unions and men’s rising contributions to household work. Because children have almost universally resided with their mothers and it is difficult for non-residential fathers to maintain any levels of care work, union dissolutions have potentially slowed societal increases in gender equality. A new family form—50/50 living arrangements—has begun to challenge our understanding of the consequences of union dissolution. Since 50/50 residence requires fathers to take full care responsibility for the child half of the time—something few partnered fathers do—it may even push parents into a more egalitarian division of care work. We have studied care work using Swedish administrative data on parents’ leave from work to care for a sick child. We have created a panel of leave-sharing for children aged 2–11, and use an event-study design to estimate the causal effect of dissolution on the sharing of sick-child leave. The results show that in parental unions dissolving today, the dissolution leads to an increase in fathers’ share of sick-child leave. Whereas union dissolutions have for decades been slowing the gender revolution in Sweden, they are now accelerating it.

Educational gradients in parental leave length are opposite for women and men: highly educated women return to work faster than those with low education while highly educated men are absent longer than less educated men. Explanations for the opposite gradients are typically made at the individual- or couple-level. To date, no quantitative study has documented whether the opposite educational gradients hold also within workplaces. In this study, we use employer-employee matched Swedish register data with fixed-effects models to examine whether the educational gradient applies also among co-workers in the same workplace. The results show that three-quarters of the educational effect typically attributed to the individual father disappeared when comparing fathers within workplaces. The educational gradient of mothers remained largely unchanged. These findings provide the first population-level evidence for the primacy of the workplace in determining fathers' care choices.

SARS-CoV-2 uses ACE2, an inhibitor of the Renin-Angiotensin-Aldosterone System (RAAS), for cellular entry. Studies indicate that RAAS imbalance worsens the prognosis in COVID-19. We present a consecutive retrospective COVID-19 cohort with findings of frequent pulmonary thromboembolism (17%), high pulmonary artery pressure (60%) and lung MRI perfusion disturbances. We demonstrate, in swine, that infusing angiotensin II or blocking ACE2 induces increased pulmonary artery pressure, reduces blood oxygenation, increases coagulation, disturbs lung perfusion, induces diffuse alveolar damage, and acute tubular necrosis compared to control animals. We further demonstrate that this imbalanced state can be ameliorated by infusion of an angiotensin receptor blocker and low-molecular-weight heparin. In this work, we show that a pathophysiological state in swine induced by RAAS imbalance shares several features with the clinical COVID-19 presentation. Therefore, we propose that severe COVID-19 could partially be driven by a RAAS imbalance. The SARS-CoV-2 receptor ACE2 is involved in the Renin-Angiotensin-Aldosterone System (RAAS). Over-activation of RAAS in swine results in a disease state similar to that of COVID-19 in human patients, suggesting that COVID-19 pathophysiology may be driven, at least in part, by an imbalance of this hormonal system.

Background: Survival after out-of-hospital cardiac arrest remains poor. Levosimendan could be a new intervention in this setting. Therefore, we conducted a blinded, placebo controlled randomized study investigating the effects of levosimendan on survival and cardiac performance in an ischemic cardiac arrest model in swine.

Methods: Twenty-four anesthetised swines underwent experimentally-induced acute myocardial infarction and ventricular fibrillation. At the start of CPR, a bolus dose of levosimendan (12 μg kg^-1) or placebo was given followed by a 24-h infusion (0.2 μg kg^-1 min^-1) after return of spontaneously circulation. Animals were evaluated by risk of death, post-resuscitation hemodynamics and infarction size by magnetic resonance imaging (MRI) up to 32 h post arrest.

Results: Spontaneous circulation was restored in all (12/12) animals in the levosimendan group compared to two thirds (8/12) in the placebo group (P = 0.09). Protocol survival was higher for the levosimendan group (P = 0.02) with an estimated 88% lower risk of death compared to placebo (hazard ratio [95% confidence interval] 0.12 [0.01-0.96], P = 0.046). Cardiac output (CO) recovered 40% faster during the first hour of the intensive care period for the levosimendan group (difference 0.13 [0.01-0.26] L min^-1P = 0.04). The placebo group required higher inotropic support during the intensive care period which masked an even bigger recovery in CO in the levosimendan group (58%). The MRI showed no difference in myocardial scar size or in myocardial area at risk.

Conclusions: Levosimendan given intra-arrest and during the first 24-h of post-resuscitation care improved survival and cardiac performance in this ischemic cardiac arrest model. Institutional Protocol Number; KERIC 5.2.18-14933.

Interview and observational studies document that dual-caring is characterized by temporality. Two ‘ideal-typical’ trajectories are identified: ‘halving it all’ in which couples divide care equally on a daily or weekly basis and ‘taking turns’ in which parents take month- or year-long turns in serving as primary caregivers to the child. This study utilizes a new source of couple-level longitudinal information on parental leave to investigate dual-caring trajectories in contemporary Sweden. Results show that while care trajectories in which only one parent serves as the primary caregiver can be captured without longitudinal information, the dominant dual-caring trajectory cannot. In fact, despite a uniquely flexible parental leave system that allows egalitarian couples to share care on a daily basis, most couples do not share care in every point in time, but ‘take turns’ in serving as the primary caregiver to the child, with the mother’s ‘turn’ preceding the father’s. The results demonstrate that cross-sectional and aggregate measures of child care may fail to detect emerging trends in dual-caring.

While most types of unpaid work have become considerably more equally divided over decades, child care that requires leave from paid work is still extremely gender specialized. Understanding conditions of paid work that can make leave-taking for both parents possible is crucial to halt the onset of gender specialization in couples. In this study, Sweden is utilized as a context in which the family policy constellation provides a real opportunity for both fathers’ and mothers’ leave-taking. The number of parental leave weeks taken by the father and the mother in the first two years of the child’s life is analyzed using administrative register data for 29,366 couples having their first child in 2009. Multi-level cross-classified models with each couple nested in 112 father and 111 mother occupations are used to estimate effects of conditions of work that have been hypothesized to hinder fathers’ leave-taking. Career costs, job insecurity and flexibility explained little variation in father leave. The strongest predictor was the father’s occupational skill level, i.e., the higher the skill level required for the occupation, the more leave fathers take. As would be expected from gendered norms and behavior and resulting gendered assumptions of care at the workplace, some of the conditions of work favorable for mothers’ leave-taking are not transferrable to fathers.

Understanding the two primary life-course events that create and accelerate gender inequality within the couple -- the transition to parenthood and parental separation -- may ameliorate their far-reaching consequences over the life-course in multiple domains of life. This thesis includes four studies on various aspects of these life-course events. The first two studies investigate division of child care at the transition to parenthood. A gender equal transition to parenthood, in which both women and men take leave off work to care for their children, is essential for couples to achieve gender equality in the family as well as in the labor market. Study I investigates the ways in which Swedish couples do such ‘dual-caring’ and shows that the dominant trajectory of dual care is characterized by taking turns as the child’s primary caregiver. Study II investigates how the domain of paid work may hinder or facilitate a gender equal transition to parenthood, focusing on economic considerations and occupational conditions of work. Study III investigates gendered division of care leave taken after couples have returned to paid work. It shows that economic differentials within the couple may shape the onset of long-term division of child care but that short-term economic incentives do not seem to alter the division. Study IV turns to parental separation as the second life-course event in which gender inequality is accelerated. As children have been most likely to live with their mothers when their parents’ union ends, parental separation typically marks the (possible) second life-course event in which unpaid work is shifted towards women. Study IV provides a method for estimating parental separation with register data and therefore making possible studies of outcomes for mothers, fathers and children who live apart.

All studies use administrative register data. These data provide a unique source of couple-level longitudinal information on all parental couples registered in Sweden. The first two studies are made possible by the availability of dated information on parental leave use. The third study accurately traces division of care leave by income composition within the couple. The last study traces parental coresidence from birth to age 15 for a period of almost four decades.

Background: Many of the dramatic changes in family formation and dissolution observed in wealthy countries over the past 60 years are tracked through vital statistics or censuses. The signature change in family behavior -- non-marital cohabitation -- is not, however, registered in most settings.

Objective: We evaluate the quality of new register-based estimates of parents' union status at birth and of separation during the childrearing years.

Methods: Parents of a common child are identified through the Multi-Generation Register that links each child to each parent and therefore each parent to each other. The Total Population Register identifies the property at which each parent is registered at the end of each year. We use the five-year censuses 1960-1990 as one standard of comparison because the censuses identify the dwelling unit for each parent on the census date.

Results: Property-based estimates of parents' coresidence compare very well to census reports. Register-based estimates are virtually identical with those produced from the 1992 Swedish Fertility and Family Survey; differences between register estimates and those produced from the 1991 and 2000 Level of Living Survey can be explained by differences in measurement of marriage and cohabitation.

Conclusions: Estimates of parents' cohabitation based on annual, property-level registration are of sufficient quality for their use in substantive analyses of union status at birth and parents' separation in Sweden.

Comments: Although register-based estimates of parents' coresidence at a child's birth or afterwards can be generated only for a select group of countries, their use can be fruitful for understanding more general processes of family change. Centralized administrative registers exist in many countries but have not been made fully available for research therefore losing much of the potential value.

The current gender-neutral care leave for care of sick children program in Sweden provides parents with a substantial number of publicly paid days per year. These are used when parents have to be absent from work to care for a sick child who cannot attend public child care. Although gender neutral from the start, women still take the majority of days. We investigate whether the existing policy design plays a role in the division of leave. We study the income cap in the program using individual-level register data for the years 2005 and 2006. We show that there seems to be a clear effect of the income cap on the division of leave: if only one partner has an income below the cap, he/she uses the majority of days. However, analyses of a policy change that raised the cap reveal no effect on the division of leave.