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AIM: To compare the efficacy of intravitreal injection of ranibizumab(IVR)and intravitreal injection of conbercept(IVC)in children with retinopathy of prematurity(ROP).METHODS: Retrospective study. A total of 1 100 eyes with ROP treated with intravitreal anti-VEGF at our hospital from January 2015 to June 2023 were included. According to the different therapeutic drugs, the children were divided into two groups: IVR group and IVC group. According to the degree of ROP, the patients were divided into three groups: aggressive ROP(A-ROP), Zone Ⅰ type 1 ROP and Zone Ⅱ type 1 ROP. The reactivation and retreatment between the two groups were compared after propensity score matching(PSM)analysis, and they were followed-up for at least 3 mo after surgery.RESULTS: In Zone Ⅱ type 1 ROP, there was a statistically significant difference in the rates of reactivation and retreatment between the IVR and IVC groups(P0.05). The risk of reactivation and retreatment of Zone I type 1 ROP was higher than the Zone II type 1 ROP. Furthermore, the use of drugs and corrected gestational age of first treatment were influencing factors of lesion recurrence and retreatment.CONCLUSION: There is a significant difference in the initial cure effect between the two drugs in Zone II type 1 ROP, with the reactivation and retreatment rates of the IVC group being much lower than those of the IVR group.

Poverty in the long run, as the long-term source of pressures, has strengthened the vulnerability of juveniles and has increased the incidence of psychological or behavioral problems during their growth. Therefore, it is necessary to strengthen preventive intervention for adolescents to avoid poverty's "scar effect" upon their physical and mental health. Explore the effect of group counseling using the Achieving Success Everyday (ASE) model on improving the resilience of junior high school students in impoverished areas. This single-blind, randomized controlled study adopted a within-subject experimental design of 2 (intervention group/control group) x 3 (pre- and post-treatment, subsequent follow-ups) and conducted group counseling intervention on seventh- to eighth-grade students in poor areas of southern Xinjiang Uyghur Autonomous Region (the group counseling lasted 8 weeks, with one session every week, 60 [approximately] 90 min for each session). The intervention effect was then evaluated using the Resilience Scale of Chinese Adolescent (RSCA), Core Self-evaluations Scale (CSES), and Simplified Coping Style Questionnaire (SCSQ). Before the intervention, there was no significant difference between RSCA, CSES, and SCSQ in the intervention group and the control group. After the intervention, the program significantly improved overall resilience scores, including three dimensions (goal focusing, positive cognition, and interpersonal assistance). And at the same time, the level of core self-evaluation and coping style has been improved, and the effect can last up to 3 months after the end of the intervention. Group counseling based on the ASE (Achieving Success Everyday) model can effectively improve students' resilience and has significant effects on improving the core self-evaluation and coping styles of the subjects.

Objective. To investigate the differences in uric acid (UA), interleukin-6 (IL-6), and free prostatic-specific antigen (fPSA)/total prostatic-specific antigen (tPSA) (F/T) between patients with and without prostate cancer (PCa) in order to discover the value of the three indicators in improving PCa diagnostic accuracy. Methods. Patients with pathologically diagnosed PCa (PCa group, n = 25), patients with other benign prostate diseases (benign group, n = 25), and men who underwent normal physical examination (control group, n = 25) at the First Affiliated Hospital of Guangzhou University of Chinese Medicine between October 2020 and January 2021 were included. The serum UA, IL-6, and F/T levels of participants in the three groups were measured, and the measured data were statistically analyzed. Results. There were statistically significant differences in IL-6 and F/T among the three groups (all P < 0.05), but there were no statistically significant differences in UA (P > 0.05). The area under the receiver operating characteristic (ROC) curve (AUC) for the three indicators was, respectively, as follows: PCa group-benign group 0.5416, 0.6776, and 0.6832; PCa group-control group 0.5432, 0.9536, and 0.9887; and benign group-control group 0.5000, 0.8784, and 0.9456. Logistic regression analysis indicated that IL-6 and F/T were independent predictors of PCa, with AUCs of 0.6776 and 0.6832, respectively, and a combined accuracy of 72.0%. Conclusion. These results suggest that IL-6 and F/T have a good detection effect for PCa screening. Compared with the detection of F/T alone, the combined detection of IL-6 and F/T can improve the diagnosis rate of PCa to a certain extent, providing effective guidance for the clinical diagnosis and treatment of patients. The value of UA needs to be further studied, and its feasibility in the diagnosis of PCa needs to be further explored. [ABSTRACT FROM AUTHOR]

Constructing a confidence interval for the ratio of bivariate normal means is a classical problem in statistics. Several methods have been proposed in the literature. The Fieller method is known as an exact method, but can produce an unbounded confidence interval if the denominator of the ratio is not significantly deviated from 0; while the delta and some numeric methods are all bounded, they are only first‐order correct. Motivated by a real‐world problem, we propose the penalized Fieller method, which employs the same principle as the Fieller method, but adopts a penalized likelihood approach to estimate the denominator. The proposed method has a simple closed form, and can always produce a bounded confidence interval by selecting a suitable penalty parameter. Moreover, the new method is shown to be second‐order correct under the bivariate normality assumption, that is, its coverage probability will converge to the nominal level faster than other bounded methods. Simulation results show that our proposed method generally outperforms the existing methods in terms of controlling the coverage probability and the confidence width and is particularly useful when the denominator does not have adequate power to reject being 0. Finally, we apply the proposed approach to the interval estimation of the median response dose in pharmacology studies to show its practical usefulness. [ABSTRACT FROM AUTHOR]

Abstract Background Over the last decade, a few studies have investigated the possible adverse effects of ambient air pollution on preterm birth. However, the correlation between them still remains unclear, due to insufficient evidences. Methods The correlation between air pollution and preterm birth in Guangzhou city was examined by using the Generalized Additive Model (GAM) extended Poisson regression model in which we controlled the confounding factors such as meteorological factors, time trends, weather and day of the week (DOW). We also adjusted the co linearity of air pollutants by using Principal Component Analysis. The meteorological data and air pollution data were obtained from the Meteorological Bureau and the Environmental Monitoring Centre, while the medical records of newborns were collected from the perinatal health database of all obstetric institutions in Guangzhou, China in 2007. Results In 2007, the average daily concentrations of NO2, PM10 and SO2 in Guangzhou, were 61.04, 82.51 and 51.67 μg/m3 respectively, where each day an average of 21.47 preterm babies were delivered. Pearson correlation analysis suggested a negative correlation between the concentrations of NO2, PM10, SO2, and temperature as well as relative humidity. As for the time-series GAM analysis, the results of single air pollutant model suggested that the cumulative effects of NO2, PM10 and SO2 reached its peak on day 3, day 4 and day 3 respectively. An increase of 100 μg/m3 of air pollutants corresponded to relative risks (RRs) of 1.0542 (95%CI: 1.0080 ~1.1003), 1.0688 (95%CI: 1.0074 ~1.1301) and 1.1298 (95%CI: 1.0480 ~1.2116) respectively. After adjusting co linearity by using the Principal Component Analysis, the GAM model of the three air pollutants suggested that an increase of 100 μg/m3 of air pollutants corresponded to RRs of 1.0185 (95%CI: 1.0056~1.0313), 1.0215 (95%CI: 1.0066 ~1.0365) and 1.0326 (95%CI: 1.0101 ~1.0552) on day 0; and RRs of the three air pollutants, at their strongest cumulative effects, were 1.0219 (95%CI: 1.0053~1.0386), 1.0274 (95%CI: 1.0066~1.0482) and 1.0388 (95%CI: 1.0096 ~1.0681) respectively. Conclusions This study indicates that the daily concentrations of air pollutants such as NO2, PM10 and SO2 have a positive correlation with the preterm births in Guangzhou, China.

Background: Studies have reported that exposure to air pollution during pregnancy was associated with preterm birth (PTB). However, it remains unknown whether this association differs between local residents and migrants.Objective: This study aimed to differentiate the associations between maternal air pollution exposure and PTB between local residents and migrants.Methods: We established a retrospective birth cohort in seven Chinese cities in Pearl River Delta (PRD) region during 2015-2017. The mothers were included in the cohort at their first time of hospital visit for pregnancy, and the endpoint events were identified using the birth registry. The air pollution exposure was estimated based on the daily air pollution concentrations in the nearby air monitoring stations during different pregnancy periods. Cox proportional hazards models were utilized to estimate the associations between each air pollutant and PTB for different pregnancy periods.Results: Our cohort included a total of 628,439 mother-and-live-birth pairs. Among them, 308,201 women were local residents, and 320,238 were migrants. We observed stronger effects of air pollutants among the migrants than the local residents. For the exposure during the entire pregnancy, the hazard ratio (HR) among the migrants and local residents were 1.56 (95% CI: 1.50, 1.63) and 0.98 (95% CI: 0.93, 1.02) for each 10 μg/m3 increase in PM2.5, 1.32 (95% CI: 1.27, 1.39) and 1.18 (95% CI: 1.12, 1.23) for each 10 ppb increase in O3, and 1.48 (95% CI: 1.40, 1.57) and 0.99 (95% CI: 0.93, 1.05) for each 10 μg/m3 increase in SO2, respectively. Similarly higher effects were observed among the migrants for the exposures in different trimesters of pregnancy. However, the effects of NO2 were comparable between the two groups.Conclusion: Our study suggests that maternal PM2.5, O3 and SO2 exposures might be important risk factors of preterm birth, particularly among the migrants. More specific protective and education measures should be considered for the migrant pregnant women. [ABSTRACT FROM AUTHOR]

Abstract Background Previous studies have reported that maternal exposure to particles with aerodynamic diameter <2.5 μm (PM 2.5) is associated with birth outcomes. However, a multicity birth cohort study has not been conducted in China, and the attributable fraction of adverse birth outcomes due to PM 2.5 exposure remains unknown. Methods We examined associations in a birth cohort of 1,455,026 mother-and-live-birth pairs who were followed up from the first hospital visit for pregnancy until the birth of the baby during 2014–2017 in nine cites of the Pearl River Delta (PRD) region, China. The PM 2.5 exposures were estimated based on the air pollution concentrations of the nearby monitors. Cox proportional hazards regressions were employed to examine the associations. Results We found 1% (HR = 1.01; 95% CI: 1.00, 1.02), 6% (HR = 1.06; 95% CI: 1.05, 1.07), and 7% (HR = 1.07; 95% CI: 1.06, 1.08) increases in risk of PTB and 20% (HR = 1.20; 95% CI: 1.18, 1.22), 18% (HR = 1.18; 95% CI: 1.15, 1.20), and 20% (HR = 1.20; 95% CI: 1.17, 1.23) increases in risk of LBW, with each 10 μg/m3 increase in PM 2.5 from trimester 1 to trimester 3, respectively. For PTB, highest HRs were observed during trimester 3, as for LBW, stronger effect were observed during trimester 1 and trimester 3. We further estimated that 7.84% (95% CI: 6.21%, 9.50%) of PTB and 14.85% (95% CI: 13.00%, 16.61%) of the LBW cases could be attributable to PM 2.5 exposure during the third trimester. Conclusion The results indicate that maternal PM 2.5 exposure is a risk factor for both LBW and PTB, and responsible for considerable burdens of PTB and LBW in the Pearl River Delta region. Highlights • We examined the effects of PM 2.5 on preterm birth and low birth weight. • PM 2.5 exposure was found to be associated with increased risk of preterm birth. • PM 2.5 exposure was observed to be associated with increased risk of low birth weight. • Substantial burden of preterm birth and low birth weight could be attributable to PM2.5 exposure. [ABSTRACT FROM AUTHOR]

Background A few studies have reported that low temperatures were associated with an increased risk of preterm birth. However, the effect of extreme weather events, such as cold spell, on preterm birth has not been studied in China. Objective This study was conducted to evaluate the impact of the 2008 cold spell on preterm birth in two subtropical cities of Guangdong Province. Methods Data of daily preterm birth, air pollution and meteorological variables from 2006 to 2010 were collected in Dongguan and Shenzhen. A Poisson regression with a distributed lag nonlinear model was used to investigate the association between the 2008 cold spell and daily rate of preterm birth for each city. Results During the 2008 cold spell, total vaginal preterm births were increased by 22.44% and 21.25% in Dongguan and Shenzhen, respectively. The effect of the cold spell on preterm births lasted for more than 1 week, the lag0–6 days cumulative relative risk (RR) is 1.32 (95% CI: 1.10–1.58) and 1.40 (95% CI: 1.18–1.68) in Dongguan and Shenzhen, respectively. The effects were found to be more pronounced for the pregnant women with 34–36 gestation weeks, maternal age < 35 years group. Conclusion This study demonstrates that cold spell could increase the risk of preterm births in Dongguan and Shenzhen, and the effect lasts for more than 1 week. Specific measures should be considered to protect the pregnant women, especially the vulnerable subgroups. [ABSTRACT FROM AUTHOR]

Background: To identify the prevention situation, the main factors influencing prevention effects and to develop control measures over retinopathy of prematurity in China.Methods: Using stratified random sampling method, we randomly selected 23 provincial and ministerial hospitals (8 in Guangdong province, 5 in Hunan province and 10 in Shaanxi province), 81 municipal hospitals (38 in Guangdong province, 19 in Hunan province and 24 in Shaanxi province), 180 district and county hospitals (76 in Guangdong province, 57 in Hunan province and 47 in Shaanxi province) in China. A total of 284 hospitals were enrolled in the study, with questionnaires distributed investigating the status and constrain factors of ROP presentation. Significant outcomes were analyzed thereafter by SPSS 19.0.Results: The screening rate of ROP in medical institutions from eastern, central and western China were 84.6%, 35.0% and 56.7%, respectively. The screening rate of tertiary and secondary medical institutions were 84.6% and 25.7% in the eastern, 35.0% and 4.9% in the central, 56.7% and 5.9% in the western region. Screening was carried out better in the tertiary than that in the secondary and primary institutions. Treatment for ROP was available in 15.7% of all the tertiary hospitals surveyed. Lack of professionals, equipments and technologies were considered to be major restrain factors for screening.Conclusions: The ROP screening and treatment status have demonstrated significant regional diversity due to uneven distribution of medical resources in China. Developed areas had established intraregional cooperation models, whereas less-developed areas should consider set up a large-scale, three-level ROP prevention network. It is of paramount importance that education and training towards ophthalmologists should be vigorously strengthened. It is strongly recommended that implement ROP telemedicine and integrated ROP prevention and management platforms through the Internet should be established. [ABSTRACT FROM AUTHOR]

Background: A few studies have examined the association between ambient temperature and preterm birth (PTB), and the results have been inconsistent. This study explored the association between ambient temperature and PTB in Shenzhen, China.Methods: Data of daily singleton PTB, air pollution and meteorological variables from 2005 to 2011 were collected in Shenzhen. A distributed lag non-linear model (DLNM) was used to investigate the association of the low and high temperatures (1st, 5th, 95th, and 99th percentiles) with PTB.Results: The median temperature was 24.5 °C and the 1st, 5th, 95th, and 99th percentiles of daily mean temperatures were 9, 12.5, 29.9 and 30.7 °C, respectively. The prevalence of singleton PTB was 5.61 % in Shenzhen. The association between temperature and PTB was not linear. There was an immediate positive association of low temperature (1st and 5th percentiles) and a negative association of high temperature (95th and 99th percentiles) with PTB. The effect of low temperature 9 °C (1st) on PTB on the current day was stronger than that of 12.5 °C (5th), with a relative risk (RR) of 1.54 (95 % CI: 1.36-1.75) and 1.49 (95 % CI: 1.35-1.63), respectively. The cumulative RR (up to 30 days) of 9 and 12.5 °C was 1.72 (95 % CI: 1.28-2.33) and 1.96 (95 % CI: 1.60-2.39), respectively. The cumulative effects (up to 30 days) of high temperature (95th and 99th percentiles) on PTB were 0.69 (95 % CI: 0.60-0.80) and 0.62 (95 % CI: 0.52-0.74), respectively. The cumulative effect (up to 30 days) of low temperatures on vaginal delivery PTB was lower than that of the cesarean section PTB with an RR of 1.58 (95 % CI: 1.12-2.22) and 1.93 (95 % CI: 1.21-3.08), respectively.Conclusions: This study suggests that low temperature might be a risk factor, while high temperature might be a protective factor of PTB in Shenzhen. [ABSTRACT FROM AUTHOR]

Previous studies have indicated maternal exposure to particles with aerodynamic diameter <2.5 μm (PM 2.5) is associated with preterm birth (PTB). However, no study has investigated this effect in pre-pregnancy impaired fasting glucose (IFG) women. This study aimed to differentiate the effects of maternal PM 2.5 exposure on PTB between pre-pregnancy IFG and normoglycemia women, and to further identify the susceptible window. This cohort study was conducted between January 2014 and December 2017 in 21 Chinese cities. All the recruited women received pre-pregnancy fasting serum glucose (FSG) tests and were followed up for their delivery outcomes. The PM 2.5 exposures were estimated by the daily air pollution concentrations of the nearby monitors. Women with FSG below 7.0 mmol/L were included in the analysis. We employed the Cox proportional hazards models to examine whether PM 2.5 exposure was associated with PTB. 237957 women were included and 7055 (3.0%) of them were pre-pregnancy IFG. During the entire pregnancy, we found 24.1% (HR = 1.241; 95% CI: 1.069, 1.439), 61.8% (HR = 1.618; 95% CI: 1.311, 1.997) and 18.6% (HR = 1.186; 95% CI: 1.004, 1.402) of increases in risk for all PTB, early PTB (20–33 gestational weeks) and late PTB (34–36 gestational weeks) among the pre-pregnancy IFG women, and 15.9% (HR = 1.159; 95% CI: 1.127, 1.192), 33.9% (HR = 1.339; 95% CI: 1.255, 1.430) and 13.2% (HR = 1.132; 95% CI: 1.098, 1.168) of increases in risk for all PTB, early PTB and late PTB among the normoglycemia women, with each 10 μg/m3 increment of PM 2.5 exposure, respectively. Furthermore, PM 2.5 exposure had the strongest effect on all PTB during trimester 1 (0–12 gestational weeks) among the pre-pregnancy IFG women, compared with the less strong effect during trimester 1 among the normoglycemia women. In conclusion, pre-pregnancy IFG increases the risk of PTB attributed to PM 2.5 , especially during trimester 1. Moreover, the effects of PM 2.5 are greater on early PTB than late PTB for both pre-pregnancy IFG and normoglycemia women. • The first study on association of PTB with PM2.5 in pre-pregnancy IFG women. • Pre-pregnancy IFG increases the risk of PTB attributed to ambient PM2.5. • Susceptible exposure windows for pre-pregnancy IFG women is the trimester 1. • Effects of PM2.5 are greater on early PTB than late PTB for pregnancy women. [ABSTRACT FROM AUTHOR]

Background: Maternal exposure to fine particulate matter (PM2.5) has been associated with a few adverse birth outcomes. However, its effect on stillbirth remains unknown in China, especially the susceptible windows and potential modifiers.Objective: This study aimed to evaluate the associations between maternal PM2.5 exposure and stillbirth in seven Chinese cities.Methods: We used birth cohort data of 1,273,924 mother-and-birth pairs in seven cities in southern China between 2014 and 2017 to examine these associations. Pregnant women were recruited in the cohort at their first visit to a doctor for pregnancy, and stillbirths were recorded at the time of birth. Air pollution exposures were assessed through linking daily air pollutant concentrations from nearby monitoring stations to the mother's residential community. Cox regression models were applied to determine the associations between PM2.5 and stillbirth for different gestational periods.Results: Among the participants, 3150 (2.47‰) were identified as stillbirth cases. The hazard ratio (HR) of stillbirths was 1.52 (95% CI: 1.42, 1.62) for each 10 μg/m3 increase in PM2.5 during the entire pregnancy after controlling for some important covariates. Relatively stronger associations were observed during the second trimester [adjusted HR = 1.67 (95% CI: 1.57, 1.77)] than trimesters 1 [HR = 1.44 (95% CI: 1.37, 1.52)] and trimester 3 [HR = 1.23 (95% CI: 1.16, 1.30)]. Stratified analyses also showed a stronger association among pregnant women without previous pregnancy and previous delivery experiences.Conclusion: The study indicates that maternal exposure to PM2.5, especially during the midpoint period of pregnancy, might increase the risk of stillbirths. Maternal previous pregnancy and delivery may modify this association. [ABSTRACT FROM AUTHOR]

Background: To achieve the goal of United Nations of elimination of new HIV infections, a program of prevention of mother-to-child transmission (PMTCT) was launched in Guangdong province. The objective of this study is to evaluate the effectiveness of the PMTCT program.Methods: The retrospective cross-section analysis was conducted using the data of case reported cards of HIV positive mothers and their infants from 2007 to 2010 in Guangdong province, and 108 pairs of eligible subjects were obtained. We described the data and compared the rates of MTCT by various PMTCT interventions respectively.Results: The overall rate of HIV MTCT was 13.89% (15) among 108 pairs of HIV positive mothers and their infants; 60.19% (65) of the mothers ever received ARVs, 80.56% (87) of infants born to HIV positive mothers ever received ARVs, but 16.67% (18) of the mothers and infants neither received ARVs. Among all the mothers and infants, who both received ARVs, received triple ARVs, mother received ARVs during pregnancy, and both received ARVs and formula feeding showed the lower rates of HIV MTCT, and the rates were 8.06%, 2.50%, 5.77%, and 6.67% respectively. In infants born to HIV positive mother, who received mixed feeding had a higher HIV MTCT up to 60.00%. Delivery mode might not relative to HIV MTCT.Conclusions: The interventions of PMTCT program in Guangdong could effectively reduce the rate of HIV MTCT, but the effectiveness of the PMTCT program were heavily cut down by the lower availability of the PMTCT interventions. [ABSTRACT FROM AUTHOR]

Background: Prior literature has found that extreme temperature exposure is associated with preterm birth (PTB). However, current evidence provides heterogeneous conclusions, and data on extreme cold and across different pre-pregnancy body mass index (BMI) statuses are limited., Methods: We conducted a population-based retrospective cohort of 251,257 women between 2014 and 2017 in Guangdong, China, to evaluate whether the association between extreme temperature exposure and PTB varied in pre-pregnancy BMI status. Participants were divided into three categories based on pre-pregnancy BMI: underweight (BMI < 18.5 kg/m 2 ), normal weight (18.5-23.9 kg/m 2 ), overweight or obesity (≥ 24.0 kg/m 2 ). We fitted Cox proportional hazards models to assess the association between daily mean temperature and PTB at each trimester for each BMI category separately. The hazard ratios (HRs) at the 5th and 95th percentiles of temperature (defined as low and high temperatures respectively) were provided using the median temperature at each trimester as a reference., Results: 58,220 (23.2%) were underweight, and 27,865 (11.1%) were overweight or obese. Of the 251,257 women, 18,612 (7.41%) had PTB delivery. Both low-and high-temperature exposure increased the risk of PTB in the third trimester, while cold exposure mostly mitigated the risk for the first and second trimesters. The association with low temperature was the strongest in the third trimester, especially for underweight women (HR: 1.825; 95%CI: 1.529 ~ 2.179), while the association with high temperature was the strongest also in the third trimester, especially for obese or overweight women (HR:1.825; 95%CI:1.502 ~ 2.218). Furthermore, the attributable fractions of PTB risk in the third trimester were estimated as 5.59% (95% CI: 3.58, 7.98%) for cold exposure among underweight women and 3.31% (95% CI: 2.01, 4.88%) for hot exposure among overweight or obese women., Conclusion: Exposure to either low temperature in the third trimester or high temperature during pregnancy was associated with a higher risk of PTB. Moreover, pre-pregnancy BMI status might affect the susceptibility of pregnant women. Such findings would be useful to develop targeted measures for vulnerable populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Qiu, Liang, Yi, Xie, Xiang, Luo and Zhao.)

Objectives: Hepatitis B virus (HBV) infection is a global public health threat, and couples of reproductive age comprise a key population in aiming to reduce both the vertical and horizontal transmission of HBV. We aimed to update knowledge on the seroepidemiology status of HBV in Guangdong, China among a large number of couples planning conception, and to identify high-risk subgroups., Design: A cross-sectional study was performed in Guangdong, China from 2014 to 2017., Setting: The data were collected from 641 642 couples (1 283 284 individuals) participating in the National Free Preconception Health Examination Project in Guangdong, China from 1 January 2014 to 31 December 2017. For each participant, sociodemographic data were obtained and a serum sample was tested for HBV infection status., Results: 161 204 individuals (12.56%) were positive for hepatitis B surface antigen (HBsAg+), and 47 318 (3.69%) were positive for both HBsAg and hepatitis B e antigen (HBsAg+ and HBeAg+). There was a higher prevalence of HBsAg+ (12.77% vs 9.42%, p<0.05) and HBsAg+ and HBeAg+ (3.77% vs 2.45%, p<0.05) among the participants with a Guangdong household registration than a non-Guangdong household registration. Similarly, the prevalence of HBsAg (13.26% vs 11.72%, p<0.05) and HBsAg+ and HBeAg+ (4.31% vs 2.94%, p<0.05) was higher among participants not living in the Pearl River Delta than those living in the Pearl River Delta. At the couple level, 12 446 couples (1.94%) were both positive; in 51 849 (8.08%), only the wife was positive; in 84 463 (13.16%), only the husband was positive. Moreover, HBsAg+ prevalence was lowest in couples where both individuals were vaccinated (18.63%) and highest in couples where neither the wife or husband was vaccinated (24.46%)., Conclusion: There was a relatively high HBsAg+ prevalence in married couples in this high-epidemic region and urgent prevention strategies are required, such as ensuring access to health services for those not living in the Pearl River Delta, and expanding vaccine programmes to high-risk adults., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Studies on the associations between maternal complications during pregnancy and childhood asthma are exclusively conducted in Western countries. The findings are mixed and may not be translated to other populations. We aimed to investigate the associations among the Chinese population and to determine whether the associations were mediated through pre-term birth, caesarean delivery, low birthweight and not breastfeeding in the first 6 months., Methods: We conducted a retrospective cohort study of 166 772 children in Guangzhou, China. Information on maternal gestational hypertension, gestational diabetes and gestational anaemia during pregnancy was extracted from medical records. Ever-diagnosis of asthma in children aged 6-12 years was obtained by questionnaire. Logistic regression models and mediation analyses were used to estimate the adjusted odds ratios (aORs) and 95% confidence intervals for childhood asthma., Results: Gestational hypertension, gestational diabetes and gestational anaemia during pregnancy were associated with an increased risk of ever-diagnosed childhood asthma: aOR 1.48 (95% CI 1.37-1.60), 1.71 (95% CI 1.65-1.78) and 1.34 (95% CI 1.26-1.45), respectively. A stronger association was observed for two or three gestational complications (aOR 2.02 (95% CI 1.93-2.16)) than one gestational complication (aOR 1.64 (95% CI 1.52-1.77)). The aOR for the three gestational complications was 1.35 (95% CI 1.26-1.45), 1.63 (95% CI 1.58-1.70) and 1.32 (95% CI 1.24-1.43), respectively, after controlling for the mediators, including pre-term birth, caesarean delivery, low birthweight and not breastfeeding in the first 6 months., Conclusions: Gestational hypertension, gestational diabetes and gestational anaemia were associated with childhood asthma, and the associations were partially explained by the mediation effects., Competing Interests: Conflict of interest: None declared., (Copyright ©The authors 2023.)

Background: Maternal exposure to fine particulate matter (PM 2.5 ) has been associated with a few adverse birth outcomes. However, its effect on stillbirth remains unknown in China, especially the susceptible windows and potential modifiers., Objective: This study aimed to evaluate the associations between maternal PM 2.5 exposure and stillbirth in seven Chinese cities., Methods: We used birth cohort data of 1,273,924 mother-and-birth pairs in seven cities in southern China between 2014 and 2017 to examine these associations. Pregnant women were recruited in the cohort at their first visit to a doctor for pregnancy, and stillbirths were recorded at the time of birth. Air pollution exposures were assessed through linking daily air pollutant concentrations from nearby monitoring stations to the mother's residential community. Cox regression models were applied to determine the associations between PM 2.5 and stillbirth for different gestational periods., Results: Among the participants, 3150 (2.47‰) were identified as stillbirth cases. The hazard ratio (HR) of stillbirths was 1.52 (95% CI: 1.42, 1.62) for each 10 μg/m 3 increase in PM 2.5 during the entire pregnancy after controlling for some important covariates. Relatively stronger associations were observed during the second trimester [adjusted HR = 1.67 (95% CI: 1.57, 1.77)] than trimesters 1 [HR = 1.44 (95% CI: 1.37, 1.52)] and trimester 3 [HR = 1.23 (95% CI: 1.16, 1.30)]. Stratified analyses also showed a stronger association among pregnant women without previous pregnancy and previous delivery experiences., Conclusion: The study indicates that maternal exposure to PM 2.5 , especially during the midpoint period of pregnancy, might increase the risk of stillbirths. Maternal previous pregnancy and delivery may modify this association., (Copyright © 2021. Published by Elsevier GmbH.)

Background: A few studies have examined the association between ambient temperature and preterm birth (PTB), and the results have been inconsistent. This study explored the association between ambient temperature and PTB in Shenzhen, China., Methods: Data of daily singleton PTB, air pollution and meteorological variables from 2005 to 2011 were collected in Shenzhen. A distributed lag non-linear model (DLNM) was used to investigate the association of the low and high temperatures (1st, 5th, 95th, and 99th percentiles) with PTB., Results: The median temperature was 24.5 °C and the 1st, 5th, 95th, and 99th percentiles of daily mean temperatures were 9, 12.5, 29.9 and 30.7 °C, respectively. The prevalence of singleton PTB was 5.61 % in Shenzhen. The association between temperature and PTB was not linear. There was an immediate positive association of low temperature (1st and 5th percentiles) and a negative association of high temperature (95th and 99th percentiles) with PTB. The effect of low temperature 9 °C (1st) on PTB on the current day was stronger than that of 12.5 °C (5th), with a relative risk (RR) of 1.54 (95 % CI: 1.36-1.75) and 1.49 (95 % CI: 1.35-1.63), respectively. The cumulative RR (up to 30 days) of 9 and 12.5 °C was 1.72 (95 % CI: 1.28-2.33) and 1.96 (95 % CI: 1.60-2.39), respectively. The cumulative effects (up to 30 days) of high temperature (95th and 99th percentiles) on PTB were 0.69 (95 % CI: 0.60-0.80) and 0.62 (95 % CI: 0.52-0.74), respectively. The cumulative effect (up to 30 days) of low temperatures on vaginal delivery PTB was lower than that of the cesarean section PTB with an RR of 1.58 (95 % CI: 1.12-2.22) and 1.93 (95 % CI: 1.21-3.08), respectively., Conclusions: This study suggests that low temperature might be a risk factor, while high temperature might be a protective factor of PTB in Shenzhen.

Background: Evidence shows exposure to ambient air pollution during pregnancy was associated with an increased risk of adverse birth outcomes, such as preterm birth, low birth weight and intrauterine growth retardation, but the results for birth defects have been inconsistent., Methods: The data on birth defects was collected from the Birth Defects Monitoring Network of Haikou city. Air pollution data for PM10, SO2 and NO2 were obtained from Haikou Environmental Monitoring Center. Logistic regression analysis was used to evaluate these associations., Results: The risk of birth defects was related to PM10 levels (adjusted OR = 1.039; 95% CI = 1.016-1.063) and SO2 levels (adjusted OR = 0.843; 95% CI = 0.733-0.969) for the second month of pregnancy. In the third month of pregnancy, the risk of birth defects was also related to PM10 levels (adjusted OR = 1.066; 95% CI = 1.043-1.090) and SO2 levels (adjusted OR = 0.740; 95% CI = 0.645-0.850)., Conclusion: The study provides evidence that exposure to PM10 and SO2 during the second and third month of pregnancy may associated with the risk of birth defects.

Background: Congenital heart defect (CHD) is the most common major malformations in infants. Little is known about the main epidemiologic characteristics of CHD prevalence in Guangdong province, China. Our study was undertaken to investigate the time trends in the prevalence of CHD in Guangdong province from 2008 to 2012., Methods: Data were retrieved from the Guangdong Hospital-Based Birth Defects Monitoring System during 2008-2012. All infants more than 28 weeks of gestation and infants up to 7 days of age in monitoring hospitals were monitored. We used prevalence rate to describe the difference in prevalence of CHD between rural and urban areas. Odds ratio (OR) and 95% confidence interval (CI) for CHD were calculated for the rural and urban areas. The CHD rate was calculated on the basis of birth defects per 10,000 births., Results: A total of 1,005,052 births were reported to the Birth Defects Monitoring Network of Guangdong Province, of which 5268 cases were diagnosed as CHD. The overall prevalence of CHD was 52.41 per 10,000 births (95% CI: 51.00 ~ 53.83) in provincial-wide, 66.08 per 10,000 births (95% CI: 63.77 ~ 68.39) in urban areas, and 40.23 per 10,000 births (95% CI: 38.52 ~ 41.93) in rural areas. The prevalence of CHD increased with maternal age both in urban areas (P < 0.01) and in rural areas (P < 0.01)., Conclusion: The increasing trends of CHD prevalence suggest that maternal age and the improvement of diagnosis ability might play a critical role.

Background: Over the last decade, a few studies have investigated the possible adverse effects of ambient air pollution on preterm birth. However, the correlation between them still remains unclear, due to insufficient evidences., Methods: The correlation between air pollution and preterm birth in Guangzhou city was examined by using the Generalized Additive Model (GAM) extended Poisson regression model in which we controlled the confounding factors such as meteorological factors, time trends, weather and day of the week (DOW). We also adjusted the co linearity of air pollutants by using Principal Component Analysis. The meteorological data and air pollution data were obtained from the Meteorological Bureau and the Environmental Monitoring Centre, while the medical records of newborns were collected from the perinatal health database of all obstetric institutions in Guangzhou, China in 2007., Results: In 2007, the average daily concentrations of NO₂, PM₁₀ and SO₂ in Guangzhou, were 61.04, 82.51 and 51.67 μg/m³ respectively, where each day an average of 21.47 preterm babies were delivered. Pearson correlation analysis suggested a negative correlation between the concentrations of NO₂, PM₁₀, SO₂, and temperature as well as relative humidity. As for the time-series GAM analysis, the results of single air pollutant model suggested that the cumulative effects of NO₂, PM₁₀ and SO₂ reached its peak on day 3, day 4 and day 3 respectively. An increase of 100 μg/m³ of air pollutants corresponded to relative risks (RRs) of 1.0542 (95%CI: 1.0080 ~1.1003), 1.0688 (95%CI: 1.0074 ~1.1301) and 1.1298 (95%CI: 1.0480 ~1.2116) respectively. After adjusting co linearity by using the Principal Component Analysis, the GAM model of the three air pollutants suggested that an increase of 100 μg/m³ of air pollutants corresponded to RRs of 1.0185 (95%CI: 1.0056~1.0313), 1.0215 (95%CI: 1.0066 ~1.0365) and 1.0326 (95%CI: 1.0101 ~1.0552) on day 0; and RRs of the three air pollutants, at their strongest cumulative effects, were 1.0219 (95%CI: 1.0053~1.0386), 1.0274 (95%CI: 1.0066~1.0482) and 1.0388 (95%CI: 1.0096 ~1.0681) respectively., Conclusions: This study indicates that the daily concentrations of air pollutants such as NO₂, PM₁₀ and SO₂ have a positive correlation with the preterm births in Guangzhou, China.