Time to pregnancy and life expectancy: a cohort study of 18 796 pregnant couples.

STUDY QUESTION: Is fecundity, measured as time to pregnancy (TTP), associated with mortality in parents? SUMMARY ANSWER: Prolonged TTP is associated with increased mortality in both mothers and fathers in a dose-response manner. WHAT IS KNOWN ALREADY: Several studies have linked both male and female fecundity to mortality. In women, infertility has been linked to several diseases, but studies suggest that the underlying conditions, rather than infertility, increase mortality. STUDY DESIGN, SIZE, DURATION: A prospective cohort study was carried out on 18 796 pregnant couples, in which the pregnant women attended prophylactic antenatal care between 1973 and 1987 at a primary and tertiary care unit. The couples were followed in Danish mortality registers from their child's birth date until death or until 2018. The follow-up period was up to 47 years, and there was complete follow-up until death, emigration or end of study. PARTICIPANTS/MATERIALS, SETTING, METHODS: At the first antenatal visit, the pregnant women were asked to report the time to the current pregnancy. Inclusion was restricted to the first pregnancy, and TTP was categorised into <12 months, ≥12 months, not planned, and not available. In sub-analyses, TTP ≥12 was further categorized into 12-35, 36-60, and >60 months. Information for parents was linked to several Danish nationwide health registries. Survival analysis was used to estimate the hazard ratios (HRs) with a 95% CI for survival and adjusted for age at the first attempt to become pregnant, year of birth, socioeconomic status, mother's smoking during pregnancy, and mother's BMI. MAIN RESULTS AND THE ROLE OF CHANCE: Mothers and fathers with TTP >60 months survived, respectively, 3.5 (95% CI: 2.6-4.3) and 2.7 (95% CI: 1.8-3.7) years shorter than parents with a TTP <12 months. The mortality was higher for fathers (HR: 1.21, 95% CI: 1.09-1.34) and mothers (HR: 1.29, 95% CI: 1.12-1.49) with TTP ≥12 months compared to parents with TTP <12 months. The risk of all-cause mortality during the study period increased in a dose-response manner with the highest adjusted HR of 1.98 (95% CI: 1.62-2.41) for fathers and 2.03 (95% CI: 1.56-2.63) for mothers with TTP >60 months. Prolonged TTP was associated with several different causes of death in both fathers and mothers, indicating that the underlying causes of the relation between fecundity and survival may be multi-factorial. LIMITATIONS, REASONS FOR CAUTION: A limitation is that fecundity is measured using a pregnancy-based approach. Thus, the cohort is conditioned on fertility success and excludes sterile couples, unsuccessful attempts and spontaneous abortions. The question used to measure TTP when the pregnant woman was interviewed at her first attended prophylactic antenatal care: 'From the time you wanted a pregnancy until it occurred, how much time passed?' could potentially have led to serious misclassification if the woman did not answer on time starting unprotected intercourse but on the start of wishing to have a child. WIDER IMPLICATIONS OF THE FINDINGS: We found that TTP is a strong marker of survival, contributing to the still-emerging evidence that fecundity in men and women reflects their health and survival potential. STUDY FUNDING/COMPETING INTEREST(S): The authors acknowledge an unrestricted grant from Ferring. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication. M.L.E. is an advisor to Ro, VSeat, Doveras, and Next. TRIAL REGISTRATION NUMBER: N/A.

Impaired fecundity as a marker of health and survival: a Danish twin cohort study.

STUDY QUESTION: Is fecundity, measured as self-reported time to first pregnancy (TTP), a marker for subsequent health and survival? SUMMARY ANSWER: Long TTP was a marker for increased mortality among women and higher hospitalization rates for both women and men. WHAT IS KNOWN ALREADY: Poor semen quality has been linked to increased mortality and morbidity from a wide range of diseases. Associations among fecundity, health and survival among women are still uncertain and studies on actual measures of fecundity and health outcomes are rare. STUDY DESIGN, SIZE, DURATION: We performed a prospective cohort study of 7825 women and 6279 men, aged 18 and above with measures on first TTP, who participated in one of the Danish nation-wide twin surveys in 1994 (twins born 1953-1976) and 1998 (twins born 1931-1952). They were followed-up for mortality and hospital admissions from the interview until 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: Twins were identified in the Danish Twin Registry and linked to Danish registers. TTP was restricted to the first pregnancy as a categorical outcome with cut-off points at 2, 10 and 18 months. We analysed the association between TTP and survival using a Cox proportional hazards model estimating hazards ratios (HRs) with 95% confidence intervals (CIs). Fine-Gray survival models were used to estimate sub-hazard ratios for specific causes of death allowing for competing risks. Using negative binomial regression, we estimated incidence rate ratios (IRRs) with 95% CIs for all-cause and cause-specific hospitalizations. All analyses were stratified by sex and adjusted for age at interview, birth cohorts, age at first attempt to become pregnant, smoking, years in school and BMI. MAIN RESULTS AND THE ROLE OF CHANCE: In the total study population, 49.9% of women and 52.7% of men reported a TTP of less than 2 months, 30.8% of women and 29.6% of men reported a TTP of 2-9 months, 6.6% of women and 5.7% of men reported a TTP of 10-17 months, and 13.3% of women and 12.0% of men reported a TTP of 18 months or more. Among 1305 deaths, we found a higher mortality for women (HR = 1.46; 95% CI 1.15, 1.87) with a TTP of ≥18 months relative to those with a TTP of <2 months, while the highest mortality was indicated for men with a TTP of 10-17 months (HR = 1.31; 95% CI 0.98, 1.74). Among 53 799 hospitalizations, we found an increased hospitalization rate among women (HR = 1.21; 95% CI 1.0-1.41) and men (HR = 1.16; 95% CI 1.00-1.35) with a TTP of ≥18 months, and for men with a TTP of 2-9 months (HR = 1.14; 95% CI 1.01-1.30). A dose-response relationship was found for women regarding both mortality (P = 0.022) and hospitalizations (P = 0.018). Impaired fecundity was associated with a wide range of diseases and some causes of death, indicating a multi-factorial causal influence on fecundity, especially among women. LIMITATIONS, REASONS FOR CAUTION: A major limitation was that fecundity depends on both partners, which was not considered in this study. Moreover, we could not obtain information on a number of potential confounders. WIDER IMPLICATIONS OF THE FINDINGS: Fecundity seems positively correlated with overall health and may be a universal marker of future health and survival. These results add knowledge to the limited findings showing that reduced fecundity in women and poor semen quality in men may reflect worse health and a shorter life, particularly among women. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by NIH grant HD096468 (M.L.E., T.K.J. and R.L.J.). The authors declare that they have no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Paternal prescription medication before conception: A retrospective cohort study of all births in Denmark 1997-2017.

AIM: To study what medication fathers are being prescribed in the months preceding conception. METHODS: A retrospective cohort study of Danish national registries, comprising all births in Denmark 1997-2017 (1.3 million births). Time trends and absolute levels of paternal prescription medication in the 6 months prior to conception were assessed. While all medications were examined (N = 1335), we focused on the main medication groups, medications that have increased in use over time, and medications for which previous evidence exists of an effect on sperm quality. RESULTS: The average number of prescriptions increased over the study period (from 0.75 prescriptions to 0.82 per birth). Polypharmacy (three or more prescriptions) increased from less than 8% to 10% of fathers. The use of pain medication, proton-pump inhibitors, selective serotonin reuptake inhibitors and some inhalants have all increased markedly over the last 20 years. CONCLUSIONS: Potential harm to the offspring done by paternal medication may present an increasing problem. As paternal medication exposure is increasing, examination of generational effects, such as major birth defects, is necessary.

Religiousness and Diseases in Europe: Findings from SHARE.

Recent research in religiousness and health suggests that epidemiological forces can have opposed effects. Here we examine two forms of religiousness and their association with disease. We performed a cross-sectional study of 23,864 people aged 50+ included in wave 1 (2004-2005) of the Survey of Health, Ageing and Retirement in Europe and a longitudinal study including people from wave 1, who were followed up during 11 years. Results suggested that taking part in a religious organization was associated with lower odds of heart attack (OR 0.74, 95% CI 0.60, 0.90), stroke (OR 0.68, 95% CI 0.50, 0.95), and diabetes (OR 0.72, 95% CI 0.58, 0.90) and longitudinally associated with lower odds of cancer (OR 0.78, 95% CI 0.60, 1.00). Conversely, praying was longitudinally associated with higher odds of heart attack (OR 1.27, 95% CI 1.10, 1.48) and high cholesterol (OR 1.12, 95% CI 1.00, 1.26). The most religious people had lower odds of stroke, diabetes, and cancer than other respondents, and in the longitudinal model, people who only prayed had higher odds of heart attack than non-religious people. Our findings lend support to the hypothesis that restful religiousness (praying, taking part in a religious organization, and being religiously educated) was associated with lower odds of some diseases, whereas little evidence was present that crisis religiousness (praying only) was associated with higher odds of disease.

Religiousness and lifestyle among Europeans in SHARE.

OBJECTIVES: Religiousness is associated with longevity and better physical health, which may be due to lifestyle choices. Here, we examine associations between religiousness and health, explained by lifestyle. STUDY DESIGN: This is a longitudinal study. METHODS: Data came from 23,864 people aged 50 and above included in the Survey of Health, Ageing and Retirement in Europe in 2004-2005 and followed up during 11 years. RESULTS: Praying and taking part in a religious organization were associated with lower odds of smoking [odds ratio (OR) = 0.82, 95% confidence interval (CI): 0.73, 0.92 and 0.61, 95% CI: 0.53, 0.70], alcohol consumption (OR = 0.71, 95% CI: 0.64, 0.78 and OR = 0.76, 95% CI: 0.67, 0.85), physical inactivity (OR = 0.88, 95% CI: 0.79, 0.98 and OR = 0.54, 95% CI: 0.48, 0.61), and doing no vigorous physical activity (OR = 0.92, 95% CI: 0.85, 0.98 and OR = 0.63, 95% CI: 0.58, 0.68). Furthermore, religious organizational involvement lowered the odds of sleep problems (OR = 0.83, 95% CI: 0.76, 0.91), whereas being religiously educated lowered the odds of high body weight (OR = 0.87, 95% CI: 0.79, 0.96). The more religious (people who prayed, took part in a religious organization and were religiously educated) had lower odds of smoking, alcohol consumption, physical inactivity, and sleep problems than other respondents, and compared with people who only prayed, they had lower odds of smoking, physical inactivity, and sleep problems. People who only prayed had lower odds of alcohol consumption but higher odds of sleep problems than the non-religious. CONCLUSIONS: This study confirms that the positive relations between religiousness and health to an important degree can be explained by lifestyle.

Semen quality associated with subsequent hospitalizations - Can the effect be explained by socio-economic status and lifestyle factors?

Semen quality is suggested to be a universal biomarker for future health. Previous studies have mostly been registry based excluding the possibility to address the importance of lifestyle, fertility status, health and socio-economic status. We aimed to investigate whether the association between semen quality and subsequent risk of hospitalization could be explained by differences in occupation, education, fertility, cryptorchidism, BMI or smoking; 1423 men with first semen sample at Fertility Clinic, Frederiksberg Hospital, Denmark, from 1977 to 2010 responded to a questionnaire in 2012 about current health, lifestyle, educational level and occupation. They were followed in the Danish National Patient Registry to first-time hospitalizations using ICD-8 and ICD-10 classification. Data were analysed by Cox proportional hazard regression models to adjust for the possible confounding factors. We found a significant higher risk of being hospitalized with decreasing sperm concentrations (0-15 mill/mL: HR1.78, 95% CI:1.51-2.09; 16-50 mill/mL: HR 1.37 95% CI: 1.17-1.60; 51-100 mill/mL: HR1.25 95% CI: 1.07-1.45). Same significant association of being hospitalized with decreasing total sperm counts was seen. The dose-response increase in risk in hospitalization with decreasing sperm concentration and total sperm count remained constant after further individual adjustment for occupation, marital status, fertility, cryptorchidism, BMI or smoking. The association between semen quality and subsequent morbidity was not explained by differences in lifestyle, behavioural or fertility status. We were unable to adjust for all possible confounders simultaneously due to limited sample size, and reverse causation is a possible explanation as information about education and lifestyle was obtained after semen analysis and hospitalizations occurred and may have changed as consequence of both. Semen quality may be a universal biomarker for future health not explained by lifestyle and socio-economic status, but this needs to be addressed further in future studies.