Background:Air pollution is a critical environmental risk factor for chronic obstructive pulmonary disease (COPD). Although numerous studies have focused on investigating this aspect, a comprehensive bibliometric overview of the global research landscape, hotspots, and emerging trends remains lacking. This bibliometric analysis aimed to examine the status, hotspots, and frontiers of research on the effect of air pollution on COPD-related health outcomes to inform COPD prevention and management. Methods:Literature was retrieved from the Web of Science Core Collection (1964 to May 31, 2025), yielding 11,167 articles and reviews. Country/institution collaboration, journal co-citation, keyword clustering, and burst detection analyses were conducted using CiteSpace, VOSviewer, and the bibliometrix package in R. Results:The number of publications increased rapidly after 1990, with Chest, European Respiratory Journal, and American Journal of Respiratory and Critical Care Medicine identified as key journals and Celli BR, Vestbo J, and Jones PW identified as prominent authors. The USA, China, and the UK led in terms of output, with Harvard University constituting the most influential institution. High-impact studies have focused on COPD attributable disease burden from air pollution (globally and in China), exposure-response mechanisms, pollution-sensitive disease risks, and indoor biomass fuel pollution. The most frequent keywords were COPD, mortality, risk, air pollution, and prevalence, with China and climate change (both emerging in 2021) serving as current frontiers. Conclusions:The bibliometric analysis results revealed that the relationship between air pollution and COPD-related health outcomes is an active research area, with major themes including disease burden, mortality, hospitalization, household air pollution, oxidative stress, and climate change.

BACKGROUND:Epidemiological studies on ambient thermal stress and fecundability are limited, and previous evidence is based on air temperature rather than a biothermal metric. Additionally, it remains unknown whether thyrotropin abnormalities serve as mediators or modifiers of the effect of thermal stress on fecundability. METHODS:We performed a nationwide cohort analysis among 14,029,184 couples from the National Free Prepregnancy Checkups Project in 31 provinces in China from 2014 to 2020. Heat and cold stress were estimated by the Universal Thermal Climate Index based on individual residential addresses. Heat (cold) stress was defined as UTCI >90th (<10th) percentiles of the province-specific distribution during the warm (cold) season. Fecundability was measured by time to pregnancy in menstrual cycles. Thyrotropin levels were measured in female participants. Accelerated failure time models were used to examine the association between thermal stress and fecundability. A 4-way decomposition mediation analysis was used to quantify the mediation and modification effects of thyrotropin abnormalities. RESULTS:We showed that exposure to heat stress and cold stress prior to (heat: time ratio [TR], 1.104; 95% CI, 1.101-1.107; cold: TR, 1.224; 95% CI, 1.221-1.228) and during pregnancy planning (heat: TR, 1.253; 95% CI, 1.248-1.259; cold: TR, 1.259; 95% CI, 1.254-1.264) was associated with reduced fecundability. Positive associations were found between heat stress and subnormal thyrotropin levels (odds ratio [OR], 1.044; 95% CI, 1.031-1.057), as well as between cold stress and supranormal thyrotropin levels (OR, 1.050; 95% CI, 1.040-1.060). Thyrotropin abnormalities could potentially mediate 1.2%-3.9% of the association of heat and cold stress with fecundability. The reference interaction of heat and cold stress with thyrotropin abnormalities accounted for 3.3%-12.1% of the total excess effect, though was not at statistically significant level. CONCLUSION:This study provides evidence that exposure to both heat and cold stress is associated with reduced fecundability, highlighting the necessity of integrating climate adaptation strategies to mitigate reproductive risks under climate change and accelerated demographic shifts.

BACKGROUND:During preconception counselling, pregnant women who smoke are advised to quit smoking. While the adverse effects of paternal smoking on pregnancy and perinatal outcomes have been increasingly recognised, the health benefits of paternal smoking cessation prior to conception remain understudied. METHODS:The current study involved non-smoking reproductive-aged Chinese women who participated two times in the National Free Prepregnancy Checkups Project during 2010-2018. A total of 158 986 pregnancies were included, with husbands reporting smoking at the preconception examination stage during their first participation. The primary exposure was paternal smoking cessation before pregnancy. And the primary outcome was spontaneous abortion (SAB) recorded in the second participation. Inverse-probability-weighted (IPW) logistic regression was used to estimate ORs and their 95% CIs of SAB with paternal smoking cessation before pregnancy. Instrumental variable (IV) analyses were further used to estimate the association. RESULTS:Compared with continued paternal smoking, paternal smoking cessation before pregnancy was associated with a reduced risk of SAB (IPW-adjusted OR 0.86 (95% CI 0.81 to 0.91); IV-estimated OR 0.79 (95% CI 0.76 to 0.82)). Additionally, a decrease in paternal smoking was also associated with a lower risk of SAB. Notably, the risk of SAB was still higher than that of those without paternal smoking in IV analysis (OR 1.21 (95% CI 1.26 to 1.32)). CONCLUSIONS:Paternal smoking cessation prior to conception is linked to a reduced risk of SAB. However, the risk of SAB among women with paternal smoking cessation was still higher than that among those without paternal smoking. Preconception counselling should advise fathers who smoke to quit.

Objective To assess the association between parental age differences (PAD) and the risk of spontaneous abortion (SAB). Methods A large-scale population-based retrospective cohort study was conducted on women aged 20-49 years who participated in the National Free Pre-pregnancy Check-ups Project and became pregnant during 2010-2018. PAD was defined as paternal age minus maternal age. To overcome the perfect collinearity between PAD and parental ages, we employed a two-stage instrumental variable approach. In the first stage, county-level average paternal and maternal ages were used as instruments to predict individual parental ages. In the second stage, inverse probability weighting based on generalized linear mixed models (GLMM) with county-level random intercepts was employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for SAB associated with PAD, adjusting for the predicted parental ages and a comprehensive set of covariates. Generalized additive mixed models (GAMM) with penalized splines were used to explore nonlinear exposure-response relationship. Results The overall incidence of SAB was 2.60%. Compared with couples with no age difference (PAD=0 years), the ORs for SAB were 1.93 (95% CI: 1.68-2.21) for a PAD of <-10 years, 1.27 (1.20-1.33) for -10 to -6 years, 1.07 (1.05-1.08) for -5 to -1 years, 1.00 (1.00-1.01) for 1 to 5 years, 1.05 (1.03-1.06) for 6 to 10 years, and 1.12 (1.09-1.16) for >10 years. A V-shaped nonlinear relationship was observed between PAD and the risk of SAB (P non-linear <0.001), with a steeper increase in risk when the female partner was older than the male partner. Conclusion Larger PAD was associated with an increased risk of SAB, especially in couples where the mother was older than the father.

Preventing impaired fasting glucose (IFG) and diabetes mellitus (DM) among reproductive-age women is important for both maternal and infant health. Although secondhand smoke exposure increases DM risk, evidence on glycemic impact from a single predominant household source remains limited. In populations with marked sex disparities in smoking prevalence, spousal smoking often constitutes women's primary exposure source. We examined temporal associations between husbands' smoking patterns with incident IFG and DM among reproductive-age Chinese women. This prospective cohort analyzed 2,828,544 couples from China's National Free Preconception Checkup Project (2010-2020) with two preconception examinations (median interval: 2.12 years). We included non-smoking women aged 20-49 years without pre-diagnosed DM and fasting plasma glucose (FPG) <7.0 mmol/L at baseline. Husbands' smoking was categorized as consistently non-smoking, consistently smoking, ex-smoking, or newly smoking. For consistently smoking husbands, we assessed smoking intensity (cigarettes per day) and cumulative exposure (pack-years). Among 2,475,950 women with baseline normal glycemia, we examined incident IFG (FPG 5.6-6.9 mmol/L) and DM (FPG ≥7.0 mmol/L or self-reported). Among 352,594 women with baseline IFG, we examined glycemic progression to DM. Of women with baseline normal glycemia, 10.1

The increasing prevalence of obesity worldwide has led to conflicting research on its cardiovascular effects. Although obesity is an established risk factor for cardiovascular disease (CVD), certain evidence indicates that a higher body mass index (BMI) might unexpectedly reduce the risk of vascular calcification. This study was designed to examine the association between BMI and the presence of abdominal aortic calcification (AAC) within a general population. We analyzed data from 3,116 adults participating in the 2013–2014 National Health and Nutrition Examination Survey (NHANES). Severe AAC was diagnosed using the Kauppila score based on dual-energy X-ray absorptiometry (DXA) scans. The relationships between BMI (treated both continuously and categorically) and severe AAC were evaluated using logistic regression. To investigate potential variations and non-linear patterns, subgroup analyses and restricted cubic spline regression were performed. After comprehensive adjustment. higher BMI was significantly associated with lower odds of severe AAC (OR = 0.89, 95

Epidemiologic evidence on thermal stress and preterm birth (PTB) is based on ambient temperature rather than a biothermal metric. Thyrotropin abnormalities have been associated with PTB and may increase thermal vulnerability. However, it remains unknown whether thermal stress and thyrotropin abnormalities synergistically contribute to increased risk of PTB. Here we conducted a nationwide cohort study among 6,218,131 singleton live births in China. Biothermal stress was measured using the Universal Thermal Climate Index. We found that both heat stress and cold stress during each trimester were associated with increased risks of PTB, with hazard ratios ranging from 1.06 (95% confidence interval [CI]: 1.05, 1.07) to 2.33 (95% CI: 2.30, 2.35) and from 1.08 (95% CI: 1.07, 1.09) to 1.68 (95% CI:1.67, 1.70), respectively. Participants with subnormal (<0.37 mIU/L) or supranormal thyrotropin levels (≥4.88 mIU/L) and biothermal stress had higher risks of PTB, compared with those with normal thyrotropin levels and non-thermal stress. Additive interactions were also identified between biothermal stress and thyrotropin abnormalities. We estimated that up to 13.52% of PTB were attributable to biothermal stress and thyrotropin abnormalities. Our study showed a synergistic effect of biothermal stress and preconceptional thyrotropin abnormalities, highlighting the importance of climate adaption measures and thyroid management toward pregnant women under climate change scenario.

Air pollution has been associated with preterm birth (PTB); however, evidence remains limited about preconception exposure. Additionally, it remains unknown whether air pollution and thyrotropin abnormalities may synergistically contribute to incident PTB. We conducted a nationwide cohort study of 6.1 million singleton births, based on the National Free Prepregnancy Checkups Project across 29 provinces in China, 2014-2020. We observed that interquartile range increases in particulate matter with diameters ≤2.5 and ≤10 μm, nitrogen dioxide, and sulfur dioxide during 12 weeks before conception through pregnancy were associated with increased risks of PTB, with the hazard ratios of 1.25 (95% confidence intervals [CI]: 1.24, 1.25), 1.13 (95% CI: 1.13, 1.14), 1.10 (95% CI: 1.09, 1.10), and 1.24 (95% CI: 1.24, 1.25), respectively. Participants with high air pollution exposure (>75th percentile) and abnormal thyrotropin levels (<0.37 or ≥4.88 mIU/L) showed higher risks of PTB, compared to those with low air pollution exposure (<25th percentile) and normal thyrotropin levels. Additive interactions were also identified between air pollution and thyrotropin abnormalities (relative excess risk due to interaction >0, attributable proportion due to interaction >0, and synergy index >1). Our study showed that exposure to air pollution during preconception through pregnancy was associated with increased risks of PTB and that air pollution and thyrotropin abnormalities may synergistically contribute to incident PTB. These findings highlight the importance of air pollution control and thyroid management.

Importance:Many studies have reported that the interpregnancy interval (IPI) is a potential modifiable risk factor for adverse perinatal outcomes. However, the association between IPI after live birth and subsequent spontaneous abortion (SA) is unclear. Objective:To investigate the association of IPI after a healthy live birth and subsequent SA. Design, Setting, and Participants:This prospective cohort study used data from 180 921 women aged 20 to 49 years who had a single healthy live birth and planned for another pregnancy and who participated in the Chinese National Free Prepregnancy Checkups Project from January 1, 2010, to December 31, 2020. Statistical analysis was conducted from June 20 to October 5, 2023. Exposure:Interpregnancy interval, defined as the interval between the delivery date and conception of the subsequent pregnancy, was categorized as follows: less than 18 months, 18 to 23 months, 24 to 35 months, 36 to 59 months, and 60 months or longer. Main Outcomes and Measures:The main outcome was SA. Multivariable-adjusted odds ratios (ORs) were calculated by logistic regression models to examine the association between IPI and the risk of SA. Dose-response associations were evaluated by restricted cubic splines. Results:The analyses included 180 921 multiparous women (mean [SD] age at current pregnancy, 26.3 [2.8] years); 4380 SA events (2.4% of all participants) were recorded. A J-shaped association between IPI levels and SA was identified. In the fully adjusted model, compared with IPIs of 18 to 23 months, both short (<18 months) and long (≥36 months) IPIs showed an increased risk of SA (IPIs of <18 months: OR, 1.15 [95% CI, 1.04-1.27]; IPIs of 36-59 months: OR, 1.28 [95% CI, 1.15-1.43]; IPIs of ≥60 months: OR, 2.13 [95% CI, 1.78-2.56]). Results of the subgroup analysis by mode of previous delivery were consistent with the main analysis. Conclusions and Relevance:This cohort study of multiparous women suggests that an IPI of shorter than 18 months or an IPI of 36 months or longer after a healthy live birth was associated with an increased risk of subsequent SA. The findings are valuable to make a rational prepregnancy plan and may facilitate the prevention of SA and improvement in neonatal outcomes.

OBJECTIVES:To comprehensively assess the association of husband smoking with wives' thyrotropin abnormality. METHODS:This population-based retrospective cohort study included 2 406 090 Chinese reproductive-aged women who had participated twice in the National Free Pre-pregnancy Checkups Project between 2010 and 2020. Multivariate-adjusted odds ratios and 95% confidence intervals for subnormal and supranormal thyrotropin were estimated according to the husband's smoking status. RESULTS:Husband smoking at the first visit was associated with a 17% (15%-20%) and 26% (24%-28%) increased odds of subnormal thyrotropin and supranormal thyrotropin respectively compared to participants in neither-smoker group. In non-smoking participants with normal thyrotropin levels at the first visit, the corresponding increased risk of subnormal thyrotropin and supranormal thyrotropin at the second visit were 15% (12%-18%) and 19% (16%-21%) in contrast to participants without husband-smoking exposure. In non-smoking participants with abnormal thyrotropin levels at their first visit, husband smoking cessation was associated with 27% (17%-35%) and 36% (31%-40%) reduced odds of subnormal thyrotropin and supranormal thyrotropin at the second visit compared with the participants whose husband still smoking at the second visit. CONCLUSION:Husband smoking was associated with wives' subnormal thyrotropin and supranormal thyrotropin, and cessation of husband smoking could reduce the odds of thyrotropin abnormality. Couple-focused smoking intervention should be developed to reduce the burden of asymptomatic thyroid disease in females.

Prevalence of subclinical hypothyroidism substantially increased during the last decade in China, which has been commonly/clinically diagnosed as elevation in thyrotropin (thyroid-stimulating hormone [TSH]). Tobacco smoke containing toxic substances has been linked to thyroid dysfunction; however, data on perturbation of TSH following air pollution exposure in human has not been assessed at nationwide population level. We investigated the longitudinal impact of daily ambient air pollution estimated at residential level on serum TSH in 1.38 million women from China's 29 mainland provinces between 2014 and 2019. We observed that particulate matter with aerodynamic diameter <= 10 and <= 2.5 mu m (PM10, PM2.5) and nitrogen dioxide (NO2) at cumulative lag 0-7 days of exposure were associated with percent elevations in TSH (0.88% [95% CI: 0.71, 1.05] per [interquartile range, IQR: 54.8 mu g/m3] of PM10; 0.89% [95% CI, 0.71, 1.07] per IQR [40.3 mu g/m3] of PM2.5; 2.01% [95% CI: 1.81, 2.22] per IQR [27.4 mu g/m3] of NO2). Greater associations were observed in participants living in areas with >= adequate iodine intake and those with low BMI levels and high inflammation status. Our results suggest that increased concentrations of recent ambient air pollutants at exposure ranges commonly encountered in Asia were associated with increases in TSH, supporting disturbing role of short-term air pollution exposure on the regulation of thyroid hormone homeostasis.

Journal Article Reply: The association between the pregnancy peripheral leukocyte and the risk of spontaneous abortion Get access Youhong Liu, Youhong Liu Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China Search for other works by this author on: Oxford Academic PubMed Google Scholar Ying Yang, Ying Yang National Research Institute for Family Planning, Beijing, ChinaNational Human Genetic Resources Centre, Beijing, ChinaGraduate School of Peking Union Medical College, Beijing, China National Research Institute for Family Planning, Graduate School of Peking Union Medical College, Beijing, China. E-mail: angela-yy65@hotmail.com (Y.Y.) https://orcid.org/0000-0002-9799-3293 Search for other works by this author on: Oxford Academic PubMed Google Scholar Long Wang Long Wang Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China Correspondence address. Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, No.199 Donggang West Road, Chengguan District, Lanzhou 730000, China. E-mail: wanglsph@lzu.edu.cn (L.W.) https://orcid.org/0000-0001-8516-0262 Search for other works by this author on: Oxford Academic PubMed Google Scholar Human Reproduction, deae075, https://doi.org/10.1093/humrep/deae075 Published: 12 April 2024

Importance:Previous evidence suggests that maternal hepatitis B virus (HBV) infection during prepregnancy or pregnancy is associated with congenital heart diseases (CHDs) in offspring. However, the association of paternal HBV infection with CHDs is not well examined. Objective:To explore the association of paternal preconception HBV infection with CHDs in offspring. Design, Setting, and Participants:This retrospective cohort study used propensity score matching of data from the Chinese National Free Preconception Checkup Project (NFPCP) from January 1, 2010, to December 31, 2018. Male participants whose wives were aged 20 to 49 years, were uninfected with HBV, and successfully conceived within 1 year after prepregnancy examination were enrolled. Data were analyzed from March 2023 to February 2024. Exposures:The primary exposure was paternal preconception HBV infection status, including uninfected, previous infection (both serum hepatitis B surface antigen and hepatitis B envelope antigen negative), and new infection (serum hepatitis B surface antigen positive). Maternal HBV immune status was further classified as immune or susceptible. Main Outcomes and Measures:The main outcome was CHDs, which were collected from the birth defect registration card of the NFPCP. Logistic regression with robust error variances was used to estimate the association between paternal preconception HBV infection and CHDs in offspring. Results:A total of 6 675 540 couples participated in the NFPCP service. After matching husbands with and without preconception HBV infection in a 1:4 ratio, 3 047 924 couples (median age of husbands, 27 years [IQR, 25-30 years]) were included in this study. Of these couples, 0.025% had offspring with CHDs. Previous paternal HBV infection was independently associated with CHDs in offspring (adjusted relative risk [ARR], 1.40; 95% CI, 1.11-1.76) compared with no infection. Similar results were obtained in subgroup analyses according to maternal HBV immune status. Compared with couples with uninfected husbands and susceptible wives, the risk of CHDs in offspring among couples with previously HBV-infected husbands was similar in couples with wives with susceptible immune status (ARR, 1.49; 95% CI, 1.10-2.03) and in those with wives with immunity (ARR, 1.49; 95%CI, 1.07-2.09). A significantly higher CHD risk in offspring was found among couples with newly infected husbands and immune wives (ARR, 1.38; 95% CI, 1.05-1.82), but there was no difference in risk among those with newly infected husbands and susceptible wives (ARR, 0.99; 95% CI, 0.72-1.36). No interactions were found between maternal immune status and paternal HBV infection. Conclusions and Relevance:In this cohort study using propensity score matching, previous paternal preconception HBV infection was associated with CHD risk in offspring. The findings suggest that personalized reproductive guidance regarding HBV screening and staying free of HBV infection should be provided for both wives and husbands.

STUDY QUESTION: Do prepregnancy peripheral leukocytes (PPLs) and their subsets influence the risk of spontaneous abortion (SAB)? SUMMARY ANSWER: PPLs and their subsets are associated with the risk of SAB. WHAT IS KNOWN ALREADY: Compelling studies have revealed the crucial role of maternal peripheral leukocytes in embryo implantation and pregnancy maintenance. Adaptive changes are made by PPLs and their subsets after conception.STUDY DESIGN, SIZE, DURATION: This population-based retrospective cohort study was based on data from the National Free Pre-pregnancy Check-up Project (NFPCP) in mainland China. Couples preparing for pregnancy within the next six months were provided with free prepregnancy health examinations and counseling services for reproductive health. The current study was based on 1 310 494 female NFPCP participants aged 20-49 who became pregnant in 2016. After sequentially excluding 235 456 participants lost to follow-up, with multiple births, and who failed to complete blood tests, a total of 1 075 038 participants were included in the primary analysis.PARTICIPANTS/MATERIALS, SETTING, METHODS: PPLs and their subset counts and ratios were measured. The main outcome was SAB. A multivariable logistic regression model was used to estimate the odds ratio (OR) and 95% CI of SAB associated with PPLs and their subsets, and restricted cubic spline (RCS) was used to estimate the nonlinear exposure-response relationship.MAIN RESULTS AND ROLE OF CHANCE: Of the included pregnant participants, a total of 35 529 SAB events (3.30%) were recorded. Compared to participants with reference values of PPLs, the ORs (95% CIs) of leukopenia and leukocytosis for SAB were 1.14 (1.09- 1.20) and 0.74 (0.69-0.79), respectively. The RCS result revealed a monotonous decreasing trend (Pnonlinear < 0.05). Similar relationships were observed for the neutrophil count and ratio, monocyte count, and middle-sized cell count and ratio. The lymphocyte ratio showed a positive and nonlinear relationship with the risk of SAB (Pnonlinear < 0.05). Both eosinophils and basophils showed positive relationships with the risk of SAB (eosinophil Pnonlinear > 0.05 and basophil Pnonlinear < 0.05).LIMITATIONS, REASONS FOR CAUTION: Chemical abortion events and the cause of SAB were not collected at follow-up. Whether women with abnormal PPLs had recovered during periconception was not determined.WIDER IMPLICATIONS OF THE FINDINGS: PPLs and their subsets are associated with the risk of SAB. Leukopenia and neutropenia screening in women preparing for pregnancy and developing a feasible PPL stimulation approach should be emphasized to utilize the immune window of opportunity to prevent SAB. STUDY FUNDING/COMPETING INTEREST(S): This study was approved by the Institutional Research Review Board of the National Health and Family Planning Commission. This study was supported by the National Key Research and Development Program of China (grants 2021YFC2700705 [Y.Y.] and 2016YFC100307 [X.M.]) and the National Natural Science Foundation of China (grant no. 82003472 [L.W.]). The funding source was not involved in the study design, data collection, analysis and interpretation of the data, writing the report, or the decision to submit this article for publication. No competing interests.TRIAL REGISTRATION NUMBER: N/A.

Objective To assess meteorological drivers of the second seasonal peaks in the incidence of hand,foot,mouth disease(HFMD)among children and adolescents in Gansu province.Methods Totally 83 462 records of 0-18 years old HFMD cases registered during 2010-2018 were collected from Gansu Provincial Center for Disease Control and Prevention and the data of same period on ambient temperature,relative humidity,rainfall,and wind speed were extracted from the Big Earth Data Platform for Three Poles.Weekly time series were established for the HFMD incidence and meteorological data.Local maximum filter and locally weighted scatter plot smoothing method were used in the identification of bimodal seasonal peaks of HFMD incidence.Logistic regression model analyses were performed to estimate the association of meteorological factors with the occurrence of second seasonal peaks of HFMD incidence,in which,the years with bimodal seasonal incidence peak were considered as the cases and those in years with monomodal incidence peak as the controls and the mean ambient temperature,relative humidity,rainfall and wind speed for 8 weeks before the identified second seasonal peak were considered as the exposure factors.Results Of the 83 190 HFMD cases finally included in the study,50 663(60.9％)were male and 77 346(93.0％)were aged less than 6 years,and more cases were reported in municipality/prefecture of Lanzhou(22 553,27.1％),Tianshui(9 756,11.7％),and Dingxi(7 917,9.5％).Of the 117 observation years for the 13 municipalities/prefecture during the 9 years,111(94.9％)of observation years had seasonal peaks of HFMD incidence,of which 92(78.6％)were with bimodal peak and only 19(16.2％)were with monomodal peak.The results of logistic regression analysis revealed a strong association between relative humidity of previous one week and the occurrence of second seasonal peak of HFMD,with a 4.2％increase(95％confidence interval[95％CI]:1.5％-7.3％)in the risk of second seasonal peak occurrence for every 1％increase in weekly average relative humidity;the results also indicated a 193.0％([95％CI]:21.9％-730.1％)increase in the risk of second seasonal peak occurrence of HFMD incidence for every 1m/s increased average weekly wind during 1-7 weeks before the second peak.Conclusion Weekly average relative humidity and wind speed are key meteorological factors correlated with the occurrence of the second seasonal peak of HFMD incidence.

Objective:To analyze the trend of the body mass index（BMI） value of women during the preparing pregnancy after the implementation of the two-child policy.Methods:A total of 33 335 352 Han Chinese women who wanted pregnancy and had participated in the National Free Pre-pregnancy Health Checkup Program in 2013-2019 were included in this study.The average BMI value,the overweight rate,and the obesity rate of the women were calculated monthly.The primiparae in these women were included in control group,and the pluriparae in these women were included in study group.A controlled interruption time series analysis was conducted to obtain the trend of the BMI value of women before and after the implementation of the two-child policy.Results:Compared with those of the women in the control group,the mean monthly BMI value change of the women in the study group was 10.01 × 10 -2 kg/m~2（95%CI-0.07-19.94,P=0.05）,and the change of the overweight/obesity rate of the women in the study group was 1.36%（95 % CI 0.36 %-2.35 %,P＜0.01）.The results of subgroup analysis showed that the change of overweight rate of the women with age≥35 years old,less than high school education level,or the farmer occupation in the study group was significantly higher than that of the women in the control group（P＜0.05）,and the obesity rate of the women with age≥35 years old,and the average GPT of 40 000-50 000 Yuan,or reside in the first-tier city in the study group had significantly different from that of the women in the control group.In the trend change,the trend change of obesity rate of the women with the aged of 30-35 years old,the per capita GPT 50 000-70 000 Yuan or≥70 000 Yuan,or reside in the second,the fourth,or the fifth tier cities had increased significantly（P＜0.05）,the trend change of overweight rate of the women with the aged of 30-50 years old,or reside in the third-tier city had increased significantly（P＜0.05）,and the trend change of overweight/obesity rate of the women with high school or above education level,vocational workers,or reside in the first or the third tier cities had decreased significantly（P＜0.05）.Conclusion:After the implementation of the universal two-child policy,there is little change in the overall trend of the BMI value among the women who are ready for pregnancy,and there are differences in the different social demographic characteristics and the different social development degree.The weight management of the women with planned pregnancy should be carried out to improve the health of the women of childbearing age.

Cardiovascular diseases, including hypertension, have posed a serious threat to human health in recent decades. Family-centered health promotion and disease control for the management of hypertension is gaining attention. In this study, we assessed the association between spousal educational attainment (SEA) and hypertension prevalence, awareness, and control, intending to provide new directions for family health care. A total of 71 211 191 reproductive-aged participants from the National Free NFPCP during 2013-2019 were included in the current study. Inverse probability weighting (IPW) via propensity models were used to adjust for the imbalance by SEA. Both multivariable-adjusted ORs and inverse-probability-weighted ORs were used to assess the association between SEA and the prevalence, awareness, and control of hypertension. ORs of prevalence, awareness, and control of hypertension with SEA stratified by sex, age, and residency type were also reported. Compared with participants with SEA of compulsory education, the inverse-probability-weighted ORs for hypertension were 0.97 (0.96-0.97), 0.99 (0.98-1.00), and 0.91 (0.88-0.93) for participants with SEA of senior high, college, and postgraduate, respectively. The corresponding ORs for hypertension awareness were 1.12 (1.10-1.13), 1.15 (1.13-1.16), and 1.38 (1.34-1.41). The increment of hypertension control associated with SEA was only identified in urban areas. Modification analyses revealed that urban participants were observed to have more healthy benefits associated with SEA; additional decreased prevalent hypertension and increased hypertension awareness associated with SEA were observed in wives and husbands respectively. Thus, SEA was associated with decreased prevalent hypertension and increased awareness and control of hypertension. Our findings call for increased participation of spouses in family-centered healthcare, with consideration of modified effects by gender, age, and residency type, to improve chronic disease prevention and control including hypertension.

目的 分析丈夫吸烟与妻子高血压患病风险之间的关联.方法 选取2010-2019年2次参加国家免费孕前优生健康检查项目的2 612 479例计划妊娠女性作为研究对象,以其丈夫2次参检时日均及累积吸烟量作为暴露,妻子2次参检时患高血压病为结局,利用logistic回归分析模型和限制性立方样条模型估计丈夫吸烟与妻子患高血压风险的OR值及其95％CI,使用敏感性分析检验结果的稳定性.结果 丈夫日均吸烟量5～10、＞10～15、＞15～20、＞20支者妻子患高血压风险分别是丈夫不吸烟者的 1.20(95％CI:1.12～1.28)、1.27(95％CI:1.16-1.40)、1.69(95％CI:1.54-1.86)和 2.07(95％CI:1.68～2.54)倍(均P＜0.05),丈夫吸烟累积暴露量为＞2.0～4.0、＞4.0～6.0、＞6.0(包·年)者妻子高血压患病风险分别比丈夫不吸烟者高24％(95％CI:11％～39％)、60％(95％CI:39％～84％)和 66％(95％CI:48％～87％)(均 P＜0.05),且患病风险随丈夫吸烟暴露量增加而增大(P趋势＜0.01).结论 丈夫吸烟量与妻子高血压患病风险呈正相关,提示加强以家庭为单位的烟草控制和高血压管理,提高育龄女性心脑血管健康水平.

Objective To explore the association of clinical and subclinical bacterial vaginosis before conception with the risk of spontaneous abortion. Design Retrospective cohort study. Setting Mainland China. Population This study included women who enrolled in and completed the National Free Pre-Pregnancy Checkups Project between January 1, 2014 and December 31, 2018. Methods Clinical bacterial vaginosis before conception was diagnosed according to the Amsel criteria, and subclinical bacterial vaginosis before conception was defined as any indicators in the Amsel Criteria being positive but not meeting the diagnostic criteria. Analyses were performed by multivaribale-adjusted logistic models with crude and multivaribale-adjusted odds ratios including 95% confidence interval. Main outcome measures Spontaneous abortion was defined as fetal death occurring spontaneously before the 28th week of gestation. Results Of the included participants, 0.27% and 6.97% of them had clinical and subclinical bacterial vaginosis before conception respectively. A significantly increased risk of spontaneous abortion was observed for women with preconception bacterial vaginosis (OR: 1.19, 95% CI: 1.06-1.34). After excluding participants with preconception bacterial vaginosis, subclinical bacterial vaginosis was associated with a 15% (13%-18%) increased risk of spontaneous abortion. And the corresponding multivariable-adjusted ORs of exposure to abnormal vaginal discharge characteristics, vaginal pH value ≥4.5, positive clue cell test, and positive Whiff test for spontaneous abortion were 1.20 (1.03-1.39), 1.15 (1.12-1.18), 1.08 (0.97-1.19), and 1.24 (1.11-1.38). Conclusion Both clinical and subclinical bacterial vaginosis before conception were prospectively associated with an increased risk of spontaneous abortion.