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.

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.

Evaluating the progression to abnormal thyrotropin in euthyroid preconception women: a population-based study.

BACKGROUND: Abnormal preconception thyrotropin levels were associated with fecundability and adverse fetomaternal outcomes, however, little is known regarding the natural change of serum thyrotropin in euthyroid preconception women. Thus, we performed a population-based study to evaluate the progression to abnormal thyrotropin in euthyroid preconception women. METHODS: This retrospective cohort study used data from the National Free Prepregnancy Checkups Project (NFPCP) collected between 2010 and 2020. Female Han Chinese participants aged 20-49 years who had two repeated NFPCP participations with a time interval of 1.5-3.0 years, confirmed non-pregnant status within this duration, and normal thyrotropin levels during their first participation were included for the analysis of thyrotropin abnormalities during the second NFPCP examination. Data were analyzed between June 1 and October 1, 2023. RESULTS: This study included 186,095 euthyroid women of reproductive age (mean ± SD, 26.72 ± 4.70 years) whose preconception thyrotropin levels were between 0.37 and 4.87 mIU/L. The median follow-up time was 2.13 (IQR, 1.85-2.54) years. A total of 8,497 (4.57%) women developed abnormal thyrotropin, including 4,118 (2.21%) subnormal thyrotropin and 4,379 (2.35%) supranormal thyrotropin. Compared with the reference group (thyrotropin 1.01-2.00 mIU/L), the lower baseline thyrotropin group had greater risk of developing subnormal thyrotropin, and the higher baseline thyrotropin group had greater risk of developing supranormal thyrotropin. Moreover, the restricted cubic spline analysis revealed a U-shaped dose-response association of baseline thyrotropin levels or thyrotropin multiples of the median (MOM) levels against risk of subnormal thyrotropin in the follow-up, and a J-shaped dose-response association against risk of supranormal thyrotropin levels in the follow-up. We further found that baseline thyrotropin outside of 1.43-1.93 mIU/L or baseline thyrotropin MOM outside 0.59-1.36 would hava a higher risk of developing of abnormal thyrotropin. CONCLUSIONS: Both low and high baseline thyrotropin were associated with a significantly increased risk of developing abnormal thyrotropin outcomes. The optimal preconception baseline thyrotropin levels may be between 1.43 mIU/L and 1.93 mIU/L or baseline thyrotropin MoM between 0.59 and 1.36 to minimize progression toward abnormal thyrotropin after 1.5-3.0 years. These findings may help with counseling of preconception thyroid function monitoring.

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.

Green space modified the association between air pollutants and hypertension in China.

Evidence regarding the combined effects of green space and air pollutants on hypertension remains limited and complex. This study aims to investigate the varying effects of greenness under different air pollution levels in China, using data from the wave 2018 China Health and Retirement Longitudinal Study (CHARLS) involving 17 468 adults (aged ≥ 45 years). As a result, the prevalence rate of hypertension was 42.04%. Logistic regression analyses revealed the positive associations between air pollution concentrations at the city level and prevalent hypertension and the negative associations between NDVI and prevalent hypertension, all of which were more prominent in the populations of the eastern and rural regions. Notably, the negative effect of green space was greater at the lowest quartiles of each air pollutant (OR for PM2.5 quartiles = 0.724, 0.792, 0.740, and 0.931) . Improving air quality and greenness could potentially reduce hypertension risk, and minimizing air pollution might optimize the protective effects of greenness.

Maternal fasting serum C-peptide concentrations in the first and second trimesters and subsequent risk of gestational diabetes mellitus: A nested case-control study among Chinese women.

OBJECTIVE: To examine the association of serum connecting peptide (C-peptide) concentrations with gestational diabetes mellitus (GDM) risk among Chinese women. METHODS: A nested case-control study was conducted on 436 reproductive-aged women, involving 218 GDM cases and 218 controls matched at 1:1 by maternal age, in Beijing, China between January 2016 and December 2017. Fasting serum C-peptide were successively determined at 10-14 and 15-20 weeks of gestation. Restricted cubic spline and logistic regression analyses were utilized, and receiver operating characteristic (ROC) curves were generated to evaluate the predictive capacity of C-peptide for GDM. RESULTS: Fasting serum C-peptide concentrations exhibited a significant decrease from the initial to the subsequent trimester in females with normal glucose tolerance (NGT). For each 1 log ng/mL increase of fasting serum C-peptide during the first and second trimesters, GDM risk increased by 2.38-fold [odds ratio (OR): 2.38, 95% confidence intervals (95%CI): 1.33-4.40] and 3.07-fold (OR: 3.07, 95%CI: 1.49-6.62), respectively. The areas under the ROC curves for the first- and second-trimester C-peptide were 80.4% and 82.4%. CONCLUSION: Our findings revealed a positive correlation between fasting serum C-peptide during the first and second trimesters and the risk of GDM or its subtypes, underscoring the potential of C-peptide as a predictor for GDM development.

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.

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.

Hematological Parameters in the First Trimester and the Risk of Gestational Diabetes Mellitus - Beijing, China, 2017-2020.

What is already known about this topic?: Hematological parameters may indicate the presence of chronic low-grade inflammation and increasing viscosity, which are involved in the pathological processes of gestational diabetes mellitus (GDM). However, the association between several hematological parameters in early pregnancy and GDM has yet to be elucidated. What is added by this report?: Hematological parameters in the first trimester, particularly red blood cell (RBC) count and systematic immune index, have a significant impact on GDM incidence. The neutrophils (NEU) count in the first trimester was particularly pronounced for GDM. The upward trend of RBC, white blood cell (WBC), and NEU counts was consistent across all GDM subtypes. What are the implications for public health practice?: Early pregnancy hematological parameters are associated with the risk of GDM.

Does the Digital Economy Increase Green TFP in Cities?

COVID-19 accelerated the growth of the digital economy and digital transformation across the globe. Meanwhile, it also created a higher demand for productivity in the real economy. Hence, the correlation between the digital economy and green productivity is worth studying as COVID-19 prevention becomes the norm. The digital economy overcomes the limitations imposed by traditional factors of production on economic growth and empowers innovative R&D and resource allocation in all aspects. This study delved into the digital economy by focusing on its green value at different levels of development. The study gathered the green-productivity indices and the principal components of the digital economy for each prefecture-level city in China from 2011 to 2019 and meticulously portrayed their trends in spatial and temporal figures. Meanwhile, regression models were used to verify the mechanism through which digital-economy development influences the changes in green productivity. The results showed that: (1) a higher level of digital economy helps to increase urban green total-factor productivity (GTFP) and that the conclusions of this paper still held after potential endogeneity problems were solved through the instrumental-variables approach; (2) the digital economy will drive an increase in urban GTFP by upgrading firms' production technologies and that digital-economy development encourages green patent applications from firms; and (3) as the digital economy develops, it will also drive urban GTFP increases by removing polluting enterprises from the market and that the higher the level of digital-economy development, the greater the number and probability of polluting enterprises exiting the market. In view of this study's results, the government should increase the importance of the digital economy, strengthen the role of the digital economy in promoting urban green development, and provide more guidance on regional green development with the help of the digital economy.

Effects of green spaces on alleviating mortality attributable to PM2.5 in China.

Increasing research suggested that green spaces are associated with many health benefits, but evidence for the quantitative relationship between green spaces and mortality attributable to particulate matter with an aerodynamic diameter of 2.5 µm or less (PM2.5) is limited. We collected disease-specific mortality and PM2.5 data for a period of 4 years (2015-2018) along with green space data for an 8-year duration (2010-2017) in 31 provincial-level administrative regions of China. First, this study used the Integrated Exposure-Response model to estimate the mortality of four diseases attributable to PM2.5, including chronic obstructive pulmonary diseases (COPD), lung cancer (LC), ischemic heart disease (IHD), and cerebrovascular disease (CBVD). Then we performed linear regression and mixed-effects model to investigate the counteracting effect of green spaces on death caused by PM2.5 exposure. The differences in impacts among the Eastern, Central, and Western regions were explored using stratified analysis. The most significant results from linear regression analysis indicated that per 100 km2 of green spaces increase, there was a decreased total mortality (10-5) (COPD, LC, IHD, and CBVD) attributable to PM2.5 by - 4.012 [95% confidence interval (CI): - 5.535, - 2.488], while the reduction by mixed-linear regression analysis was - 2.702/105 (95% CI = - 3.645, - 1.759). Of all hysteresis analyses, the effect estimates (ß) at lag3 and lag4 were the largest. The effect of green spaces was more advantageous when targeting CBVD and the Eastern region. We found a negative correlation between green space exposure and mortality attributable to PM2.5, which can provide further support for city planners, government personnel, and others to build a healthier city and achieve national health goals.

Dynamics of Photoexcited Small Polarons in Transition-Metal Oxides.

The dynamics of photoexcited polarons in transition-metal oxides (TMOs), including their formation, migration, and quenching, plays an important role in photocatalysis and photovoltaics. Taking rutile TiO2 as a prototypical system, we use ab initio nonadiabatic molecular dynamics simulation to investigate the dynamics of small polarons induced by photoexcitation at different temperatures. The photoexcited electron is trapped by the distortion of the surrounding lattice and forms a small polaron within tens of femtoseconds. Polaron migration among Ti atoms is strongly correlated with quenching through an electron-hole (e-h) recombination process. At low temperature, the polaron is localized on a single Ti atom and polaron quenching occurs within several nanoseconds. At increased temperature, as under solar cell operating conditions, thermal phonon excitation stimulates the hopping and delocalization of polarons, which induces fast polaron quenching through the e-h recombination within 200 ps. Our study proves that e-h recombination centers can be formed by photoexcited polarons, which provides new insights to understand the efficiency bottleneck of photocatalysis and photovoltaics in TMOs.

Superatom Molecular Orbital as an Interfacial Charge Separation State.

Hot electron cooling by energy loss to heat through electron-phonon (e-ph) interaction is an important mechanism that can limit the efficiency of solar energy conversion. To avoid such energy loss, sufficient charge separation needs to be realized by extracting hot carriers from the photoconverter before they cool, which requires fast interfacial charge transfer and slow internal hot carrier relaxation. Using ab initio time-dependent nonadiabatic molecular dynamics and taking C60/MoS2 as a prototype system, we show that the superatom molecular orbitals (SAMOs) of fullerenes, which are bound by the central potential of the whole molecule induced by the charge screening, are ideal media for charge separation. The diffuse character of SAMOs results in extremely weak e-ph interaction and therefore acts as a "phonon bottleneck" for hot electron cooling. Furthermore, it also leads to significant hybridization with other atoms at the interface that induces fast charge transfer. The interfacial charge-transfer rate at the C60/MoS2 interface is found to be 2 orders of magnitude faster than the hot electron cooling from s-SAMO in C60. This conclusion is generally applicable for different carbon nanostructures that have SAMOs. The proposed SAMO-induced charge separation provides unique and essential insights into the material design and function for solar energy conversion.