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Introduction Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent synthetic chemicals found in consumer products, firefighting foam, and contaminated food and water. (1) Routes of exposure include ingestion, inhalation, and [...]

Background Objective Methods Results Conclusion The use of fertility indicators to predict ovulation has largely been studied for contraceptive purposes, while less so as fertility‐promoting tools.To investigate the association between fertility indicators and fecundability in Danish women trying to conceive.Web‐based preconception cohort study. We analysed data from 11,328 females aged 18–49 years trying to conceive without fertility treatment for ≤6 menstrual cycles, from the Danish SnartGravid.dk and SnartForældre.dk cohorts (2007–2023). Participants reported the use of fertility indicators (counting days since the last menstrual period, cervical fluid monitoring, urinary ovulation testing, feeling ovulation, using a smartphone fertility app and measuring basal body temperature [BBT]). Time to pregnancy was measured in menstrual cycles ascertained by self‐reported pregnancy status. We estimated fecundability ratios (FR) and 95% confidence intervals (CIs) using proportional probabilities regression models adjusted for age, socio‐economic position, health indicators, reproductive history and gynaecological factors.Fertility indicators were used by 63.3% of participants at study entry. Counting days was the most common (46.9%), while measuring BBT was the least (3.0%). Other indicators ranged from 17.0% to 23.6%, with 69.7% using more than one indicator. Compared with non‐use, use of any fertility indicator was associated with greater fecundability (adjusted FR 1.14, 95% CI 1.08, 1.19). Cervical fluid monitoring showed the strongest association (aFR 1.46, 95% CI 1.03, 2.07), followed by urinary ovulation testing (aFR 1.35, 95% CI 1.16, 1.58) and counting days (aFR 1.18, 95% CI 1.09, 1.29). Feeling ovulation and fertility apps were modestly associated with fecundability, while measuring BBT was not associated. Sensitivity analysis restricting to ≤2 cycles of attempt time and two cycles of follow‐up showed an aFR for any indicator use of 1.21 (95% CI 1.13, 1.31).In this Danish preconception cohort, use of fertility indicators was associated with a higher fecundability, varying by type of indicator. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Is cervical intraepithelial neoplasia (CIN) associated with reduced fecundability, defined as the probability of conceiving per menstrual cycle? SUMMARY ANSWER Overall, we observed no meaningful association between CIN and fecundability, regardless of surgical status, although a recent diagnosis of moderate or severe CIN might be associated with slightly reduced fecundability for 2 years after diagnosis. WHAT IS KNOWN ALREADY About 15% of couples experience infertility. Few studies have examined the influence of CIN on fertility, and the results have been inconsistent. No study has investigated the association between fecundability and pathologist-reported CIN diagnoses, particularly with respect to the recency of the specific CIN diagnoses. STUDY DESIGN, SIZE, DURATION This prospective cohort study included 9586 women trying to conceive. The women were enrolled from 1 June 2007 to 3 February 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS Women were invited to complete a baseline questionnaire and bimonthly follow-up questionnaires for up to 12 months or until pregnancy occurred. Data on cervical cytologies and biopsies were retrieved from The National Pathology Registry (DNPR), which holds records of all cervical specimens examined in Denmark. Women were categorized based on their most severe diagnosis of CIN: no lesion, other cervical changes, mild CIN (CIN1), or moderate/severe CIN (CIN2+) with or without surgery. To investigate the association between CIN and fecundability, we computed fecundability ratios (FR) and 95% confidence intervals (CI) using a proportional probabilities regression model. We adjusted for age at study entry, partner age, body mass index, smoking status, timing of intercourse, parity, education, number of sexual partners, and household income. MAIN RESULTS AND THE ROLE OF CHANCE Compared with no lesion, the adjusted FRs (95% CI) for the association between CIN and fecundability were: other cervical lesions, 0.97 (0.91–1.04); CIN1, 1.04 (0.96–1.13); CIN2+ no surgery, 1.00 (0.82–1.22); and CIN2+ with surgery 0.99 (0.89–1.10). The FRs (95% CI) for a recent diagnosis (<2 years) of CIN were 0.98 (0.86–1.11) for other cervical lesions; 1.13 (0.99–1.29) for CIN1; 0.89 (0.62–1.26) for CIN2+ no surgery and 0.91 (0.75–1.10) for CIN2+ with surgery compared with the no lesion group. LIMITATIONS, REASONS FOR CAUTION In the analyses, we adjusted for several covariates related to the women. However, we had little information on the male partners which could lead to unmeasured confounding as fecundability is a couple-based measure of fertility. Furthermore, a CIN diagnosis may not be constant as it may regress or progress spontaneously; therefore, it is possible that we have misclassified some women, especially women categorized as having normal cells or CIN1. WIDER IMPLICATIONS OF THE FINDINGS Our results contribute important knowledge to women who are concerned about their future fertility after receiving a CIN diagnosis. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by The Danish Cancer Society (R167-A11036-17-S2). The overall cohorts were funded by the National Institute of Child Health and Human Development (R01-HD086742 and R03-HD094117). The authors report no competing interests. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

The fecal immunochemical test (FIT) has been implemented in colorectal cancer (CRC) screening programs, but effect evaluations are lacking. We evaluated the effect of a positive FIT on all-cause and CRC mortality using the regression discontinuity design. The Danish CRC screening program invites all residents 50–74 years old, using a 20-μg hemoglobin/g feces cutoff for colonoscopy referral. In this cohort study, we followed all first-time screening participants from 2014–2019 until 2020. We estimated the local effect of screening results, of just above the cutoff vs. just below, as hazard ratios (HRs) between models fitted at each side of the cutoff. We conducted the analysis within a narrow hemoglobin range (≥17 and <23, n  = 16,428) and a wider range (≥14 and <26, n  = 35,353). Those screened just above the cutoff had lower all-cause mortality compared with below (HR = 0.87, 95% confidence interval: 0.69; 1.10), estimated from the narrow range. The CRC mortality analysis had few outcomes. In the wider range, those with a FIT just above the cutoff had a lower hazard of CRC mortality compared with just below the cutoff (HR = 0.49, 95% confidence interval: 0.17; 1.41). A FIT result just above the cutoff, leading to referral to colonoscopy, pointed towards reduced all-cause and CRC mortality compared with just below the cutoff. [ABSTRACT FROM AUTHOR]

Background: Psychological stress is prevalent among reproductive‐aged men. Assessment of semen quality for epidemiological studies is challenging as data collection is expensive and cumbersome, and studies evaluating the effect of perceived stress on semen quality are inconsistent. Objective: To examine the association between perceived stress and semen quality. Material and methods: We analyzed baseline data on 644 men (1,159 semen samples) from two prospective preconception cohort studies during 2015–2021: 592 in Pregnancy Study Online (PRESTO) and 52 in SnartForaeldre.dk (SF). At study entry, men aged ≥21 years (PRESTO) and ≥18 years (SF) trying to conceive without fertility treatment completed a questionnaire on reproductive and medical history, socio‐demographics, lifestyle, and the 10‐item version of the Perceived Stress Scale (PSS; interquartile range [IQR] of scores: 0–40). After enrollment (median weeks: 2.1, IQR: 1.3–3.7), men were invited to perform in‐home semen testing, twice with 7–10 days between tests, using the Trak Male Fertility Testing System. Semen quality was characterized by semen volume, sperm concentration, and total sperm count. We fit generalized estimating equation linear regression models to estimate the percent difference in mean log‐transformed semen parameters by four PSS groups (<10, 10–14, 15–19, ≥20), adjusting for potential confounders. Results: The median PSS score and IQR was 15 (10–19), and 136 men (21.1%) had a PSS score ≥20. Comparing men with PSS scores ≥20 with <10, the adjusted percent difference was −2.7 (95% CI: −9.8; 5.0) for semen volume, 6.8 (95% CI: ‐10.9; 28.1) for sperm concentration, and 4.3 (95% CI: −13.8; 26.2) for total sperm count. Conclusion: Our findings indicate that perceived stress is not materially associated with semen volume, sperm concentration, or total sperm count. [ABSTRACT FROM AUTHOR]