The prevalence of preterm and low birth weight infants among migrant women in the Pearl River Delta region, China: a population-based birth cohort study.

BACKGROUND: The existing literature evaluating the association between neonatal morbidity and migrant status presents contradictory results. The purpose of this study was to compare the risk of preterm birth (PTB) and low birth weight (LBW) among newborns from local and migrant women in China's Pearl River Delta (PRD) region. METHODS: In this observational population-based study, we included all live singleton deliveries from PRD region local women and migrant women. Data were sourced from the Guangdong Medical Birth Registry Information System between Jan 1, 2014, and Dec 31, 2020. Women were categorized into three groups by maternal migrant status: local women from PRD region, migrant women from Guangdong province or from other provinces. The outcome variables that were examined included two adverse birth outcomes: PTB and LBW. The association between the risk of PTB and LBW and maternal migrant status was assessed using logistic regression. RESULTS: During 2014-2020, 5,219,133 single live deliveries were recorded, corresponding 13.22% to local women and the rest to migrant women coming from Guangdong (53.51%) and other provinces (33.26%). PTB prevalence was highest among local women (5.79%), followed by migrant women from Guangdong (5.29%), and the lowest among migrants from other provinces (4.95%). This association did not change after including maternal age, infant sex, delivery mode, and birth season in the models. Compared to local women, migrant women from other provinces had a lower risk of LBW (4.00% vs. 4.98%, P < 0.001). The prevalence of PTB and LBW was higher among local women than migrants. The odds of delivery PTB and LBW were higher for women who were age ≥ 35. Among the three maternal migration groups, the age-LBW association displayed a typical U-shaped pattern, with those in the youngest (16-24 years) and oldest (≥ 35) age categories exhibiting the higher odds of delivering a LBW neonate. With respect to infant sex, the prevalence of PTB was significantly higher in males than females among the three maternal migration groups. An opposite trend was found for LBW, and the prevalence of LBW was higher in females among the three maternal migration groups. CONCLUSION: The findings of this study contribute to the understanding of the epidemiology of PTB and LBW among migrant women. Our study suggests that it is the health and robust nature of migrant mothers that predisposes them to better birth outcomes. It is important to recognize that the results of this study, while supportive of the healthy migrant effect, cannot be considered definitive without some exploration of motivation for moving and changes in lifestyle postmigration.

Co-occurrence of Spondyloepiphyseal Dysplasia and X-Linked Hypophosphatemia in a Three-Generation Chinese Family.

Rare genetic skeletal disorders (GSDs) remain the major problem in orthopedics and result in significant morbidity in patients, but the causes are highly diverse. Precise molecular diagnosis will benefit management and genetic counseling. This study aims to share the diagnostic experience on a three-generation Chinese family with co-occurrence of spondyloepiphyseal dysplasia (SED) and X-linked hypophosphatemia (XLH), and evaluate the therapeutic effects of two third-generation siblings. The proband, his younger brother, and mother presented with short stature, skeletal problems, and hypophosphatemia. His father, paternal grandfather, and aunt also manifested short stature and skeletal deformities. Whole exome sequencing (WES) of proband-brother-parents initially only found the proband and his younger brother had a pathogenic c.2833G > A(p.G945S) variant in the COL2A1 gene inherited from their father. Re-analysis of WES uncovered the proband and his younger brother also harbored a pathogenic ex.12 del variant in the PHEX gene transmitted from their mother. Sanger sequencing, agarose gel electrophoresis, and quantitative polymerase chain reaction proved these results. The proband and his younger brother were confirmed to have a paternally inherited SED and a maternally inherited XLH. During a 2.8-year follow-up, these two siblings remained short stature and hypophosphatemia, but their radiographic signs and serum bone alkaline phosphatase levels were improved with treatment of oral phosphate and calcitriol. Our study presents the first report of co-occurrence of SED and XLH, shows the possibility that two different rare GSDs co-exist in a single patient, and alerts clinicians and geneticists to be cautious about this condition. Our study also suggests that next-generation sequencing has limit in detecting exon-level large deletions.

PM2.5 exposure increases the risk of preterm birth in pre-pregnancy impaired fasting glucose women: A cohort study in a Southern province of China.

Previous studies have indicated maternal exposure to particles with aerodynamic diameter <2.5 µm (PM2.5) 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 PM2.5 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 PM2.5 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 PM2.5 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 PM2.5 exposure, respectively. Furthermore, PM2.5 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 PM2.5, especially during trimester 1. Moreover, the effects of PM2.5 are greater on early PTB than late PTB for both pre-pregnancy IFG and normoglycemia women.

Penalized Fieller's confidence interval for the ratio of bivariate normal means.

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.

A systematic study on the prevention and treatment of retinopathy of prematurity in China.

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.

Temporal trends of preterm birth in Shenzhen, China: a retrospective study.

BACKGROUND: Preterm birth is the leading cause of child mortality under 5 years of age. Temporal trends in preterm birth rates are highly heterogeneous among countries and little information exists for China. To address this data gap, we investigated annual changes in preterm birth incidence rate and explored potential determinants of these changes in Shenzhen, China. METHODS: A total of 1.4 million live births, during 2003-2012, were included from the Shenzhen birth registry. Negative-binominal regression models were used to estimate the annual percent changes in incidence. To identify the potential determinants behind temporal trends, we estimated the contribution of each changing risk factor to changes in rate by calculating the difference in population-attributable risk fraction. RESULTS: Annual preterm birth incidence rates increased by 0.94% (95% CI 0.30%, 1.58%) overall, 3.60% (95% CI 2.73%, 4.48%) for medically induced, and 3.13% (95% CI 1.01%, 5.31%) for preterm premature rupture of membranes, but decreased by 2.34% (95% CI 1.62%, 3.06%) for spontaneous preterm labor. Higher maternal educational attainment (0.20 rate increase), lower proportion of inadequate prenatal care (0.15 rate reduction), more multipara (0.08 rate reduction), decreased proportion of preeclampsia or eclampsia (0.05 rate reduction), and larger proportion of young and older pregnant women (0.04 rate increase) were significant contributors to the overall change over time. Contributions of changing risk factors were different between preterm birth subtypes. CONCLUSIONS: Preterm birth rate in Shenzhen, China increased overall during 2003-2012, although trends varied across three preterm birth subtypes. The rising rates were associated with changes in maternal education and age.

The association between ambient temperature and preterm birth in Shenzhen, China: a distributed lag non-linear time series analysis.

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.

Prevalence of congenital heart defect in Guangdong province, 2008-2012.

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.

Ambient air pollution and birth defects in Haikou city, Hainan province.

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.

Effectiveness of a prevention of mother-to-child HIV transmission program in Guangdong province from 2007 to 2010.

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.

Epidemiology of hepatitis B virus infection among preconception couples in South China: a cross-sectional study.

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.

Extreme temperature exposure increases the risk of preterm birth in women with abnormal pre-pregnancy body mass index: a cohort study in a southern province of China.

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/m2), normal weight (18.5-23.9 kg/m2), overweight or obesity (≥ 24.0 kg/m2). 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.

Associations between maternal complications during pregnancy and childhood asthma: a retrospective cohort study.

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.

Exploration of the Value of Combined UA, IL-6, and fPSA/tPSA in the Diagnosis of Prostate Cancer.

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.

The Asian Games, air pollution and birth outcomes in South China: An instrumental variable approach.

We estimate the effects of air-pollution exposure on low birthweight, birthweight, and prematurity risk in South China, for all expectant mothers and by maternal age group and child sex. We do so by exploiting exogenous improvement in air quality during the 2010 Guangzhou Asian Games, when strict regulations were mandated to assure better air quality. We use daily air-pollution levels collected from monitoring stations in Guangzhou, the Asian Games host city, and Shenzhen, a nearby control city, between 2009 and 2011. We first show that air quality during the Asian Games significantly improved in Guangzhou, relative to Shenzhen. Next, using birth-certificate data for both cities for 2009-2011 and using expected pregnancy overlap with the Asian Games as an instrumental variable, we study the effects of three pollutants (PM10, SO2, and NO2) on birth outcomes. Four main conclusions emerge: 1) air pollutants significantly reduce average birthweight and increase preterm risk; 2) for birthweight, late pregnancy is most sensitive to PM10 exposure, but there is not consistent evidence of a sensitive period for other pollutants and outcomes; 3) for birthweight, babies of mothers who are at least 35 years old show more vulnerability to all three air pollutants; and 4) male babies show more vulnerability than female babies to PM10 and SO2, but birthweights of female babies are more sensitive than those of male babies to NO2.

Effects of air pollution on neonatal prematurity in Guangzhou of China: a time-series study.

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.

Prevalence of small for gestational age infants in 21 cities in China, 2014-2019.

Infants who are small for gestational age (SGA) are at increased risk of neonatal and infant death, non-communicable diseases and growth retardation. However, the epidemiological characteristics of SGA remain unclear. We aim to explore the prevalence of SGA and to examine its socioeconomic associations by using data from 21 cities. 10,515,494 single live birth records between 2014 and 2019 from the Guangdong Women and Children Health Information System were included in the study. Descriptive statistical methods were used to analyze the prevalence trend of SGA and its distribution. We also analyze the associations between the prevalence of SGA and per-capita GDP. The prevalence of SGA in Guangdong Province from the years 2014-2019 was 13.17%, 12.96%, 11.96%, 12.72%, 11.45%, 11.30% respectively, and the overall prevalence was 12.28%. The prevalence of term SGA infants in Guangdong Province was 12.50%, which was much higher than that of preterm SGA (7.71%). There was a significant negative correlation between the SGA prevalence and per-capita GDP in 21 cities of Guangdong Province. The level of economic development may affect the prevalence of SGA. The prevalence of SGA in full term infants is significantly higher than in premature infants, suggesting that most SGA infants may be born at a later gestational age.

Maternal PM2.5 exposure associated with stillbirth: A large birth cohort study in seven Chinese cities.

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.

Exosomal miR-486-5p derived from human placental microvascular endothelial cells regulates proliferation and invasion of trophoblasts via targeting IGF1.

Preeclampsia (PE) is a serious complication of pregnancy. Exosomes are known to be upregulated in PE. In this study, we sought to investigate the effect of miR-486-5p from human placental microvascular endothelial cells, on the function of trophoblast cells. To investigate the function of human placental microvascular endothelial cell (HPVEC)-derived exosomes on trophoblast cells, HPVECs were treated with hypoxia/reoxygenation (H/R). The separation efficiency of exosomes was determined by transmission electron microscopy, nanosight and Western blot. Cell Counting Kit-8, EdU staining, wound-healing, and transwell assay were performed to detect the effect of exosomally transferred miR-486-5p inhibitor on proliferation, migration and invasion of trophoblast cells. MiRDB and dual-luciferase report assay were used to find the target of miR-486-5p. Our data revealed that miR-486-5p was significantly upregulated in H/R-treated HPVEC-Exo, and miR-486-5p was enriched in HPVEC-Exo. miR-486-5p inhibitor carried by HPVEC-Exo significantly inhibited the proliferation, migration and invasion of trophoblast cells. Insulin-like growth factor 1 (IGF1) was found to be the target of miR-486-5p, and IGF1 overexpression notably reversed the effect of miR-486-5p inhibitor from HPVEC-Exo on trophoblast cell function. In summary, H/R-treated HPVEC-derived exosomally expressing miR-486-5p inhibitor significantly inhibited the proliferation, migration and invasion of trophoblast cells via downregulation of IGF1. The findings from the present study may be useful in the development of treatments for PE.

Proteomics analysis of potential serum biomarkers for insulin resistance in patients with polycystic ovary syndrome.

The aim of the present study was to identify potential serum biomarkers for insulin resistance (IR) in patients with polycystic ovary syndrome (PCOS) by comparing the differences in serum protein expression levels between PCOS patients with and without IR. PCOS patients aged from 18 to 35 years were recruited at Guangdong Women and Children's Hospital from January, 2013 to February, 2014. A total of 218 PCOS patients were enrolled and divided into the insulin resistance (PCOS­IR) and non­insulin resistance (PCOS­NIR) groups according to their homeostasis model assessment of insulin resistance. Two­dimensional difference gel electrophoresis (2D­DIGE) and matrix­assisted laser desorption/ionization time­of­flight mass spectrometry (MALDI­TOF­MS/MS) techniques were used to identify differences in protein expression levels between the PCOS­IR and PCOS­NIR groups. The present study demonstrated that the total cholesterol (TCH), triglycerides (TG), low­density lipoprotein (LDL), fasting plasma glucose (FPG), 3­h blood glucose (3hBG) and uric acid (UA) levels in the PCOS­IR group were higher than those in the PCOS­NIR group (P<0.05). Between the PCOS­IR and PCOS­NIR groups, a total of 20 differentially expressed protein spots were detected by 2D­DIGE. Among these, 4 proteins, namely afamin, serotransferrin, complement C3 and apolipoprotein C3 (APOC3), were also identified by MALDI­TOF­MS/MS. The alteration of APOC3 was further confirmed by western blot analysis and enzyme­linked immunosorbent assay (ELISA). The present study also confirmed that the expression level of APOC3 was positively associated with the homeostasis model assessment of insulin resistance (HOMA­IR). On the whole, the data indicate that APOC3 may be a potential diagnostic marker for PCOS­IR patients.