Association of psychological stress with wives' hypertension across over 10 million Chinese married female population aged 20-49 years.

BACKGROUND: Psychological stress has been reported to be a potential risk factor for hypertension among females, but it remains unclear whether spousal chronic stress levels alter the risk of hypertension among women. We examined the associations between stress within the family and hypertension among married women. METHODS: Reproductive-aged women who were planning for pregnancy and their husbands were recruited from the National Free Pre-pregnancy Checkup Projects (NFPCP) across 31 provinces in China in 2016 and 2017. Perceived stress of wives or husbands was measured with a 5-point Likert-type scale, and assessed from three domains: work/life-related stress, economic stress, and overall stress. Multivariable-adjusted logistic regression models were used to assess the associations between stress status and the prevalence of hypertension. RESULTS: Of 10,027,644 couples, 261,098 (2.60%) women had hypertension. The results showed that higher stress levels among themselves or their husbands were associated with a higher prevalence of hypertension in women ( Pfor trend <0.001). Compared with non-stressed participants, female participants with the highest stress themselves were at a greater risk of hypertension, with adjusted odds ratio (OR) of 1.31 (95% confidence interval [CI]: 1.25-1.37); and compared with participants whose husbands had no stress, those whose husbands had the highest stress level were at a higher risk of hypertension with adjusted OR of 1.24 (95% CI: 1.20-1.29). Moreover, compared with non-stressed status for both couples, only-wife-stressed, only-husband-stressed, and both-stressed couples were found to be significantly associated with increased risks of wives' hypertension, with adjusted ORs of 1.28 (95% CI: 1.25-1.31), 1.19 (95% CI: 1.17-1.21), and 1.28 (95% CI: 1.26-1.31), respectively. CONCLUSION: Moderate to severe stress in both spouses might be associated with female hypertension prevalence, which highlights the importance of paying attention to the psychological stresses of couples within the family.

Interpregnancy Interval After Healthy Live Birth and Subsequent Spontaneous Abortion.

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.

Detection method of micro and macro scale defects in silicon carbide castings.

Aiming at challenges such as low efficiency, high missing rate, difficulty in identifying contour defects, and difficulty in extracting tiny defects, a defect detection method for extracting micro and macro scale defects is proposed in this paper. After preprocessing the image, contour detection is performed to identify the contours. Subsequently, a contour complementation algorithm is employed to complement the unclosed contours. Finally, the detection of micro scale defects is conducted based on the grayscale variation of the center of the micro scale defects. The experimental results show that compared with the traditional method, the proposed algorithm can accurately detect the bubble defects of different scales in silicon carbide castings and can identify the complex defects better.

Association between fine particulate matter and fecundability in Henan, China: A prospective cohort study.

OBJECTIVE: To investigate the relationship between ambient fine particulate matter (PM2.5) exposure and fecundability. METHODS: This study included 751,270 female residents from Henan Province who participated in the National Free Pre-conception Check-up Projects during 2015-2017. Ambient cycle-specific PM2.5 exposure was assessed at the county level for each participant using satellite-based PM2.5 concentration data at 1-km resolution. Cox proportional hazards models with time-varying exposure were used to estimate the association between fecundability and PM2.5 exposure, adjusted for potential individual risk factors. RESULTS: During the study period, 568,713 participants were pregnant, monthly mean PM2.5 concentrations varied from 25.5 to 114.0 µg/m3 across study areas. For each 10 µg/m3 increase in cycle-specific PM2.5, the hazard ratio for fecundability was 0.951 (95 % confidence interval: 0.950-0.953). The association was more pronounced in women who were older, with urban household registration, history of pregnancy, higher body mass index (BMI), hypertension, without exposure to tobacco, or whose male partners were older, with higher BMI, or hypertension. CONCLUSION: In this population-based prospective cohort, ambient cycle-specific PM2.5 exposure was associated with reduced fecundability. These findings may support the adverse implications of severe air pollution on reproductive health.

Long-Term Exposure to Fine Particulate Matter and Fasting Blood Glucose and Diabetes in 20 Million Chinese Women of Reproductive Age.

OBJECTIVE: Evidence of the associations between fine particulate matter (PM2.5) and diabetes risk from women of reproductive age, in whom diabetes may have adverse long-term health effects for both themselves and future generations, remains scarce. We therefore examined the associations of long-term PM2.5 exposure with fasting blood glucose (FBG) level and diabetes risk in women of reproductive age in China. RESEARCH DESIGN AND METHODS: This study included 20,076,032 women age 20-49 years participating in the National Free Preconception Health Examination Project in China between 2010 and 2015. PM2.5 was estimated using a satellite-based model. Multivariate linear and logistic regression models were used to examine the associations of PM2.5 exposure with FBG level and diabetes risk, respectively. Diabetes burden attributable to PM2.5 was estimated using attributable fraction (AF) and attributable number. RESULTS: PM2.5 showed monotonic relationships with elevated FBG level and diabetes risk. Each interquartile range (27 µg/m3) increase in 3-year average PM2.5 concentration was associated with a 0.078-mmol/L (95% CI 0.077, 0.079) increase in FBG and 18% (95% CI 16%, 19%) higher risk of diabetes. The AF attributed to PM2.5 exposure exceeding 5 µg/m3 was 29.0% (95% CI 27.5%, 30.5%), corresponding to an additional 78.6 thousand (95% CI 74.5, 82.6) diabetes cases. Subgroup analyses showed more pronounced diabetes risks in those who were overweight or obese, age >35 years, less educated, of minority ethnicity, registered as a rural household, and residing in western China. CONCLUSIONS: We found long-term PM2.5 exposure was associated with higher diabetes risk in women of reproductive age in China.

Maternal Preconception Serum Alanine Aminotransferase Levels and Risk of Preterm Birth among Reproductive-Aged Women - China, 2013-2017.

What is already known about this topic?: The significance of maternal liver health concerning preterm birth (PTB) is well recognized; however, there is a gap in understanding the precise influence of preconception serum alanine aminotransferase (ALT) levels on the risk of PTB. What is added by this report?: In this retrospective cohort study, a J-shaped relationship between preconception serum ALT levels and risk of PTB was observed, indicating that both significantly elevated and decreased ALT levels may contribute to the risk. What are the implications for public health practice?: Maintaining optimal preconception serum ALT levels may reduce the risk of PTB, thereby informing specific preventive measures for women of reproductive age.

Role of iron oxide in retarding the graphitization of de-oiled asphaltenes for amorphous carbon.

The solvent deasphalting (SDA) process is widely recognized as a significant technology in processing inferior oil. However, de-oiled asphaltene (DOA), which accounts for about 30% of feedstocks, is not well utilized in conventional processing methods to date. Considering its complicated structure and high heteroatom and metal contents, DOA is suitable for preparing amorphous carbon. Herein, we obtained amorphous carbon from inferior de-oiled asphaltene through direct carbonization of a mixture of DOA and Fe2O3 and revealed the mechanism of iron oxide in retarding graphitization to increase the disordered structure content. After the addition of Fe2O3, XRD results showed that the content of amorphous carbon increased from 25.57% to 59.48%, and a higher defect degree could also be observed in Raman spectra, thus resulting in better electrochemical performance in Na-ion half-cells. As a coke core, Fe2O3 could accelerate the polycondensation of asphaltene molecules; meanwhile, oxygen species derived from Fe2O3 could capture excess H free radicals in the initial pyrolysis stage, which inhibited the formation of planar polycyclic aromatic molecules and weakened π-π interactions. Moreover, O atoms could embed into the carbon skeleton by reacting with DOA at higher temperatures, which could further twist and break the intact carbon layer. Both of the factors enhanced the proportion of amorphous carbon. This work not only provides a new understanding of controlling the carbonization process, but it also promotes the development of the SDA process.

Perinatal prevalence of birth defects in the Mainland of China, 2000-2021: a systematic review and meta-analysis.

BACKGROUND: Although birth defects are of great concern globally, the latest national prevalence has not yet been quantified in China. We conducted a systematic review and meta-analysis to estimate the perinatal prevalence of birth defects in the Mainland of China between 2000 and 2021. METHODS: We performed a systematic literature search of six databases for relevant articles published between January 1, 2000, and March 1, 2023. We included published studies that reported data on the perinatal prevalence of birth defects in the Mainland of China. The DerSimonian and Laird random-effects models were used to estimate the pooled prevalence and its 95% confidence interval (CI). We also conducted subgroup analyses and univariable meta-regressions to explore differences in prevalence by time period, geographic region, and other characteristics. RESULTS: We included 254 studies reporting the perinatal prevalence of birth defects and 86 studies reporting only the prevalence of specific types of birth defects. Based on 254 studies covering 74,307,037 perinatal births and 985,115 cases with birth defects, the pooled perinatal prevalence of birth defects was 122.54 (95% CI 116.20-128.89) per 10,000 perinatal births in the Mainland of China during 2000-2021. Overall, the perinatal prevalence of birth defects increased from 95.60 (86.51-104.69) per 10,000 in 2000-2004 to 208.94 (175.67-242.22) per 10,000 in 2020-2021. There were also significant disparities among different geographical regions. Congenital heart defects (33.35 per 10,000), clefts of the lip and/or palate (13.52 per 10,000), polydactyly (12.82 per 10,000), neural tube defects (12.82 per 10,000), and inborn errors of metabolism (11.41 per 10,000) were the five most common types of birth defects. The perinatal prevalence among males was significantly higher than that among females (ß = 2.44 × 10-3, P = 0.003); a higher perinatal prevalence of birth defects was observed among perinatal births whose mothers were ≥ 35 years (ß = 4.34 × 10-3, P < 0.001). CONCLUSION: Comprehensive and sustained efforts are needed to strengthen surveillance and detection of birth defects, improve prenatal and postnatal healthcare, and promote rehabilitation, especially in underdeveloped areas.

Husband smoking is associated with Wife's thyrotropin abnormality: A population-based cohort study among Chinese reproductive-aged women.

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.

Preconception folic acid supplementation for the prevention of birth defects: a prospective, population-based cohort study in mainland China.

BACKGROUND: Folic acid supplementation is recommended for reducing the risk of birth defects. We aimed to assess the protective association of periconception folic acid supplements with birth defects in real-world setting. METHODS: This prospective, population-based cohort study utilized national preconception registered data of married Chinese couples planning a pregnancy within 6 months between 2010 and 2012 in Mainland China. Participated women are freely provided folic acid starting 3 months before conception till 3 months after conception. Birth defects were self-reported at 42 days postpartumn followup. R software (v4.0.2) was applied for statistical analyses. RESULTS: Complete data of 567,547 couples with pregnancy outcomes and folic acid supplementation were extracted for final analysis. A total of 74.7% women were with folic acid supplementation, and 599 birth defects were self-reported. The odd of birth defects was lower among women taking folic acid compared to their counterparts not taking (0.102% vs 0.116%, P < 0.001). In the multiple logistic regression analyses, the odd of birth defects was lower among couples with maternal folic acid supplementation (OR = 0.78, 95%CI: 0.66-0.95, P = 0.011), especially decreased odd of neural tube defects (NTDs) (OR = 0.56, 95%CI: 0.39-0.82, P = 0.003). This association was confirmed by 1:4 and 1:10 case control analysis. Odds of birth defects were significantly lower among women with folic acid supplementation more than 3 months before pregnancy (P < 0.001), and moreover, the odds of cleft (P = 0.007) and NTDs (P = 0.007) were of notable decrease. CONCLUSION: This retrospective case cohort study provides programmatic evidence for public health strategy-making to for reducing the risk of NTDs and clefts.

Mechanistic studies of HF/BF3-catalyzed anthracene polymerization to prepare mesophase pitch.

CONTEXT: The mesophase pitch prepared by acid catalytic method typically had the advantages of low softening point and high solubility. To fully understand the mechanism of acid-catalyzed reactions and gain a deeper understanding of the microstructure of mesophase pitch, this article studied the mechanism of hydrofluoride/boron trifluoride (HF/BF3)-catalyzed anthracene using molecular simulation methods. The results showed that there might be two types of carbocations present in the system: classical and non-classical carbocations, and five reactions might occur, protonation reaction, chain elongation reaction, intramolecular cyclization reaction, deprotonation reaction, and dehydrogenation reaction. Classical carbocations acted as reactive intermediates in the chain elongation reaction and intramolecular cyclization reaction. When anthracene occurred chain elongation reactions with carbocations to form polymers, the generation of the tetramer required lager energy barriers than that of the dimer and trimer. The stiffness and flatness of molecules could be increased via intramolecular cyclization reactions. The polymers of anthracene might also occurred dehydrogenation reactions when the non-classical carbocations played the role of reactive intermediates. The dehydrogenation reactions required large energy barriers, which might be the reason for the product having a high aliphatic hydrogen content. METHOD: The Materials Studio (MS) 2020 software was used to complete the simulation. The atomic charge distribution calculation and the structure optimization of molecules were carried out using the B3LYP functional and DNP basis. The DFT-D (TS) dispersion corrections were added to calculate the dispersion interaction between aromatic molecules. The complete LST/QST method was used to search the transition states and calculate the reaction energy barrier.

An immune window of opportunity to prevent spontaneous abortion: prepregnancy peripheral leukocytes and subsets were associated with a decreased risk of spontaneous abortion.

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.

Gravidity modifies the associations of age and spousal age difference with couple's fecundability: a large cohort study from China.

STUDY QUESTION: Do couple's age ranges for optimal fecundability, and the associations with fecundability of couple's age combinations and age differences differ with gravidity? SUMMARY ANSWER: The couple's age range of optimal fecundability and age combinations differed with gravidity, and gravidity might modify the associations of age and spousal age difference with couple's fecundability. WHAT IS KNOWN ALREADY: Age is one of the strongest determinants of fecundability, but the existing studies have certain limitations in study population, couple's extreme age combinations and age differences, and have not explored whether the association between age and fecundability differs with gravidity. STUDY DESIGN, SIZE, DURATION: Retrospective cohort study. 5 407 499 general reproductive-aged couples (not diagnosed with infertility) participated in the National Free Pre-conception Check-up Projects during 2015-2017. They were followed up for pregnancy outcomes through telephone interviews every 3 months until they became pregnant or were followed up for 1 year. PARTICIPANTS/MATERIALS, SETTING, METHODS: The main outcome was time to pregnancy, and the fecundability odds ratios and 95% CIs were estimated using the Cox models for discrete survival time. The associations of age and spousal age difference with fecundability were evaluated by restricted cubic splines. MAIN RESULTS AND THE ROLE OF CHANCE: In this large cohort of general reproductive-aged population, the age of optimal fecundability of multigravida couples was older than that of nulligravida couples, but their subsequent fecundability declined more sharply with age. The decline in female fecundability was more pronounced with age, with fecundability dropping by ∼30% in both nulligravida and multigravida couples whose female partners aged ≥35 years. In the nulligravida group, the fecundability of couples who were both ≤24 years with the same age was the highest, which decreased steadily with the increase of spousal age difference, and younger male partners did not seem to contribute to improving couple's fecundability. In the multigravida group, couples with female partners aged 25-34 years and a spousal age difference of -5 to 5 years showed higher fecundability, and the effect of spousal age difference on couple's fecundability became suddenly apparent when female partners aged around 40 years. Young male partners were unable to change the decisive effect of female partner's age over 40 years on couple's reduced fecundability, regardless of gravidity. LIMITATIONS, REASONS FOR CAUTION: Lacking the time for couples to attempt pregnancy before enrollment, and some couples might suspend pregnancy plans during follow-up because of certain emergencies, which would misestimate the fecundability. Due to the lack of information on sperm quality and sexual frequency of couples, we could not adjust for these factors. Moreover, due to population characteristics, the extrapolation of our results required caution. WIDER IMPLICATIONS OF THE FINDINGS: The couple's age range of optimal fecundability, age combinations, and spousal age difference on fecundability varied with gravidity. Female age-related decline in fecundability was more dominant in couple's fecundability. Targeted fertility guidance should be provided to couples with different age combinations and gravidities. STUDY FUNDING/COMPETING INTEREST(S): This research received funding from the Project of National Research Institute for Family Planning (Grant No. 2018NRIFPJ03), the National Key Research and Development Program of China (Grant No. 2016YFC1000307), and the National Human Genetic Resources Sharing Service Platform (Grant No. 2005DKA21300), People's Republic of China. The funders had no role in study design, analysis, decision to publish, or preparation of the manuscript. The authors report no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Association between short-term air pollution exposure and perturbation in thyrotropin levels in 1.38 million Chinese women: A national longitudinal analysis, 2014-2019.

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 µm (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 µg/m3] of PM10; 0.89% [95% CI, 0.71, 1.07] per IQR [40.3 µg/m3] of PM2.5; 2.01% [95% CI: 1.81, 2.22] per IQR [27.4 µg/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.

Structural transition of parenthood among Chinese nulliparous couples with planned pregnancies, 2013-2019.

BACKGROUND: The postponement of parenthood is a global public health issue that has received attention of many public health experts. However, few studies have investigated the postponement in marriage age, marriage and conception interval, and pregnancy age in terms of demographic and regional heterogenicities. METHODS: This is a cross-sectional, registry-based study, and a total of 13 894 601 nulliparous couples who participated in the National Free Pre-Pregnancy Check-ups Project and became pregnant during 2013-2019 were included. We calculated annual percentage change and forest plots for marriage age, marriage and conception interval, and pregnancy age. RESULTS: Late marriage (marriage age ≥ 35 years), long marriage and conception interval (marriage and conception interval ≥ 2 years), and advanced pregnancy (pregnancy age ≥ 35 years) increased from 1.20%, 22.01%, and 1.88% in 2013 to 1.69%, 32.75%, and 2.79% in 2019, respectively. The corresponding annual percentage changes were 6.55%, 8.44%, and 8.17%. Participants without higher education had a higher annual percentage change, but comparable prevalence for long marriage and conception interval with participants with higher education. Participants residing in second- or new first-tier cities, and the northeast of China who had a higher prevalence of parenthood postponement also had higher corresponding annual percentage changes. CONCLUSIONS: Structural postponement of parenthood with demographic and regional heterogenicities was observed among Chinese nulliparous couples with planned pregnancies during 2013-2019. Inclusive and comprehensive parenting support should be developed and implemented in mainland China to minimize the negative health effects arising from the postponement, especially for couples without higher education and living in new first/second-tier cities or the northeast China.

Evaluating the Impact of Maternal Exposure to Ozone on Twin Fetal Growth in China.

Unlike singletons, twins require attention not only to the birth weight of the fetuses but also to discordance (i.e., the differences between weights) because twin growth discordance is a significant factor contributing to perinatal mortality and morbidity in twin pregnancies. However, the impact of maternal air pollution exposure on twin growth discordance has rarely been investigated. We examined the association of long-term ozone exposure during preconception and pregnancy with the birth weight of twins and twin growth discordance among 35,795 twins from the National Free Preconception Health Examination Project between January 2010 and December 2019. Linear mixed-effect models and random-effect logistic regression models were used to examine the associations of ozone exposure with the birth weight-related outcomes (i.e., birth weight of twins and within-pair birth weight difference) and risk of twin growth discordance, respectively, after adjustment for demographic characteristics and lifestyle. We found that an interquartile range (IQR) increase (15 µg/m3) in ozone exposure during the entire pregnancy was associated with a reduction (-28.96g, 95% confidence interval [CI]: -46.37, -11.56) in the total birth weight of twins, and ozone had a more pronounced impact on the birth weight of the smaller fetuses (-18.28 g, 95% CI: -27.22, -9.34) compared to the larger fetuses (-9.88 g, 95% CI: -18.84, -0.92) in twin pregnancies. An IQR increase in ozone exposure during the entire pregnancy was associated with a significant increase (8.41 g, 95% CI: 4.13, 12.69) in the within-pair birth weight difference; the odds ratio (OR) of twin growth discordance related to ozone exposure increased by 9% (OR = 1.09, 95% CI: 1.01, 1.18). However, no consistently significant associations were observed for ozone exposure during prepregnancy. Male-male twin pairs and those who were born prematurely appeared to be more susceptible to ozone exposure than their counterparts. Long-term ozone exposure during pregnancy was associated with twin growth discordance, and our findings provide reference data for future studies.

The association between the maternal pre-pregnancy platelet count and fecundability in mainland China: a population-based cohort study.

BACKGROUND: Currently, awareness about platelet count (PC) and its consequences for perinatal outcome have increased, but there is little reliable evidence on fecundability. METHODS: Based on the National Free Pre-conception Check-up Projects supported by the Chinese government, 5,524,886 couples met the inclusion criteria were included in this cohort study. Cox regression models were adopted to estimate fecundability ratios (FRs) and their 95% confidence intervals for pre-pregnancy PC quintiles. Restricted cubic splines were used to flexibly model and visualize the relationship of PC with FRs. Microsoft SQL server and R software were used for data management and analysis. RESULTS: The median of pre-pregnancy PC among women was 221.00×109/L. The first (<177.00 ×109/L) and second quintile (177.00-207.99 ×109/L) of PC showed slightly increased fecundability (Q1: adjusted FR 1.05, 95% CI 1.04-1.06; Q2: adjusted FR 1.04, 95% CI 1.03-1.05), while higher quintals (Q4: 236.00-271.99 ×109/L; Q5: ≥272.00 ×109/L) were related to reduction of fecundability, when compared with the third quintile of PC (208.00-235.99 ×109/L) (Q4: adjusted FR 0.96, 95% CI 0.95-0.97; Q5: adjusted FR 0.88, 95% CI 0.87-0.89). In the first quintiles (<177.00×109/L), only 20.93% women had PC below 129.94×109/L. An inverse-U shape association was consistently observed among women such that the lower PC of normal range (<118.03×109/L) and higher PC (>223.06×109/L) were associated with the risk of reduced female fecundability (P for non-linearity < 0.01). CONCLUSION: PC is associated with female fecundability. Further classification of PC levels may deepen our understanding of the early warnings and significance of female fecundability.

Declined prevalence, improved awareness and control of hypertension are associated with spousal educational attainment: A mega-data study.

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.

Effects of crystal structure and electronic properties on lithium storage performance of artificial graphite.

Graphite is nowadays commonly used as the main component of anode materials of lithium-ion batteries (LIBs). It is essential to deeply investigate the fundamentals of artificial graphite to obtain excellent anode, especially crystal structure and electronic properties. In this report, a series of graphite with different crystal structure were synthesized and used for anodes of LIBs. Meanwhile, a concise method is designed to evaluate qualitatively the conductivity of lithium ion (σLi) and a profound mechanism of lithium storage was revealed in terms of solid state theory. The conductivity analysis demonstrates that the graphite with longer crystal plane and lower stacking layers possesses higher conductivity of electron (σe). On the other hand, lower initial charge/discharge voltage indicates the graphite with lower La and higher Lc holds higher conductivity of lithium ion (σLi). According to the solid state theory, graphite is considered to be a semi-conductor with zero activation energy, while the lithium intercalated graphite is like a conductor. The conductivity of graphite mainly depends on the σe, while the conductivity of lithium intercalated graphite can be determined by the summation of σe and σLi. In lower charge/discharge rate, Li+ have enough time to insert into the graphitic layer, making the special capacity of graphite primarily determined by σe. However, with the increase of charge/discharge rate, Li+ insertion/extraction will become more difficult, making σLi become the mainly factor of the graphite special capacity. Therefore, the graphite with longer crystal plane and lower stacking layers owns higher specific capacity under slow charge/discharge rate, the graphite with shorter crystal plane and higher stacking layers shows relatively lower specific capacity under rapid charge/discharge rate. These results provide important insights into the design and improvement of graphite's electrochemical performance.

Assessment of Prior Infection With Hepatitis B Virus and Fecundability in Couples Planning Pregnancy.

IMPORTANCE: The association of hepatitis B virus (HBV) infection with reduced fecundability among reproductive-aged couples lacks large-population, in-depth study evidence. OBJECTIVE: To investigate the association of HBV infection with time to pregnancy in couples planning pregnancy, and to explore whether this association varied by gravidity, health statuses, or lifestyles. DESIGN, SETTING, AND PARTICIPANTS: This is a population-based cohort study of Chinese couples participating in the National Free Preconception Check-up Projects during 2015 to 2017. They were planning pregnancy and were followed-up every 3 months until getting pregnant, as confirmed by gynecologic ultrasonography, or were followed-up for 1 year. Data were analyzed between March 1, 2022, and September 30, 2022. MAIN OUTCOMES AND MEASURES: The main outcome was time to pregnancy, assessed using fecundability hazard ratios (HRs). The Cox proportional hazards regression models were used to estimate the association of HBV infection with fecundability. RESULTS: Among 2 419 848 couples (mean [SD] age, 27.87 [5.20] years for women and 29.58 [5.50] years for men), 126 728 women (5.24%) and 156 572 men (6.47%) were infected with HBV. Compared with the HBV-negative group, the fecundability of both women and men in the HBV-positive group decreased by 5% (HR, 0.95; 95% CI, 0.94-0.95). Compared with couples in which both partners were HBV negative, the fecundability of those in which both partners were HBV positive declined by 6% (HR, 0.94; 95% CI, 0.93-0.96) among all couples, by 3% (HR, 0.97; 95% CI, 0.95-0.99) among nulligravidas couples, and by 7% (HR, 0.93; 95% CI, 0.91-0.95) among multigravidas couples. Both the female-male and couple models suggested that the association of HBV infection with decreased fecundability was more pronounced in couples with multigravidas. The negative association was greater in people with overweight and obesity and was inconsistent in certain subgroups; in particular, it was more pronounced in women with reproductive tract infections, normal fasting plasma glucose, and no alcohol intake and in men with normal blood pressure. CONCLUSIONS AND RELEVANCE: In this population-based cohort study, HBV infection was associated with decreased fecundability in a general reproductive-aged population, especially in couples with multigravidas. For women and men with certain health statuses and lifestyles, a comprehensive consideration of this association is recommended to provide personalized fertility guidance.