Secular variation and risk factors of preterm birth in Hainan, the Free Trade Port in China from 2010 to 2021.

OBJECTIVES: Preterm delivery rates have increased obviously worldwide over the past decade, yet reliable epidemiological studies on the incidence of preterm birth and temporal trends are not available in Hainan, The Free Trade Port in China. We aimed to describe the rate of preterm birth and trends between 2010 and 2021 and to primarily explore risk factors associated with preterm birth in Hainan, China. METHODS: This was an observational study was based on data from the Hainan Provincial Birth Certificate System (HPBCS) for live births between 1 January 2010 and 31 December 2021. We included pregnancies resulting in at least one live birth, with newborns born at a gestational age of 28 weeks or greater, or with a birth weight of 1000 g or more. The outcome were preterm birth rates and their trends over time. Potential risk factors were collected, including infant gender, maternal age, paternal age, maternal ethnicity, paternal ethnicity, home address, and single or multiple pregnancies. The logistic regression model was used to assess the relationship between preterm birth and potential risk factors. RESULTS: A total of 1,537,239 live births and 86,328 preterm births were investigated, giving a total preterm birth rate of 5.62%. The overall preterm birth rate increased from 4.47% in 2010 to 7.12% in 2021 (compound annual growth rate [CAGR] 4.32). The CAGR of late preterm birth is consistent with the overall preterm birth rate (4.32%). The fastest growth is observed in the rate of very preterm births (5.53%), while the rate of moderate preterm births exhibits the slowest growth (3.87%). Infant gender, multiple pregnancy, home address, parental age, and ethnicity had significant effects on preterm birth. CONCLUSION: The preterm birth rate was increasing year by year from 2010 to 2021 in Hainan, The Free Trade Port in China. Incidence of preterm births in Hainan Province in relation to multiple pregnancies, infant sex, parental age, parental race and residential address.

The reference curves of percentile for the length and head circumference of infants aged 0-1 year in Hainan Province, China.

We first established percentile reference curves for infant length and head circumference in Hainan Province based on gender and age in months and compared them with the 2022 national standards and World Health Organization (WHO) standards. This cross-sectional survey involved 2736 infants (1471 boys and 1265 girls) in 18 cities and counties in Hainan Province. Standardized instruments were used to measure head circumference and length. Reference values for Hainan infants' length and head circumference were determined using the LMS method. Curves were generated using the LMS Chart Maker software. According to the newly established reference curves, the length and head circumference of Hainan infants exhibited a consistent trend of steady growth. However, the average head circumference was below the 2022 national reference values and WHO standards. The mean length was lower than the new national reference values but roughly consistent with the WHO standards. Differences exist in infant length and head circumference in Hainan compared to national and global averages. To enhance infant length and head circumference growth, the health department should encourage exclusive breastfeeding for the first 6 months, ensure infants' sleep needs at night, and promote the regularity of vitamin D supplementation during the perinatal period.

Epidemiology of obesity and influential factors in China: a multicenter cross-sectional study of children and adolescents.

OBJECTIVE: To determine the prevalence of and risk factors for overweight and obese among Chinese children and adolescents. METHODS: This analytical cross-sectional study included 16,640 children and adolescents aged 6-18 years across four provinces of China in 2016. Physical characteristics and responses to questionnaires were analyzed. Body Mass Index (BMI) and the prevalence of overweight and obesity were calculated. RESULTS: Among children and adolescents, the overall prevalence of overweight and obesity in 2016 in four regions of China was 27.2% and 29.6%, respectively. Among different stages and sexes, the highest prevalence of obesity (15.8%) was observed in adolescent boys. From childhood to adolescence, the obesity rate among boys increased by 0.7% (from 15.1% to 15.8%), while the obesity rate among girls decreased by 0.9% (from 10.8% to 9.9%). Children and adolescents who were overweight or obese had significantly higher systolic blood pressures, larger waist circumferences and larger hip sizes than those with a normal BMI. Logistic regression analyses identified thirteen factors associated with overweight or obesity in children and adolescents. CONCLUSIONS: Our results indicate that the prevalence of overweight and obesity is high among children and adolescents, especially among male adolescents in four regions of China. A suitable intervention program should not only help parents understand the serious risk of childhood obesity but also, more importantly, help to encourage a healthy lifestyle among children and adolescents.

Prevalence and factors associated with pentavalent vaccination: a cross-sectional study in Southern China.

BACKGROUND: Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives. A complex immunization schedule, however, may be burdensome to parents and lead to reduced vaccine compliance and completion. Thus, it is critical to develop combination vaccines to reduce the number of injections and simplify the immunization schedule. This study aimed to investigate the current status of the pentavalent diphtheria-tetanus-acellular pertussis inactivated poliomyelitis and Haemophilus influenzae type B conjugate (DTaP-IPV/Hib) vaccination in Southern China as well as explore the factors in the general population associated with uptake and the differences between urban and rural populations. METHODS: A cross-sectional study was conducted with recently enrolled kindergarten students in Hainan Province between December 2022 and January 2023. The study employed a stratified multistage cluster random sampling method. Information regarding the demographic characteristics and factors that influence decisions were collected from the caregivers of children via an online questionnaire. Multivariate logistic regression was used to determine the factors associated with the status of DTap-IPV/Hib vaccinations. RESULTS: Of the 4818 valid responses, 95.3% of children were aged 3-4 years, and 2856 (59.3%) held rural hukou. Coverage rates of the DTaP-IPV/Hib vaccine, from 1 to 4 doses, were 24.4%, 20.7%, 18.5%, and 16.0%, respectively. Caregivers who are concerned about vaccine efficacy [adjusted odds ratio (aOR) = 1.53, 95% confidence interval (CI): 1.30-1.79], the manufacturer (aOR = 2.05, 95% CI: 1.69-2.49), and a simple immunization schedule (aOR = 1.26, 95% CI: 1.04-1.54) are factors associated with a higher likelihood of vaccinating children against DTaP-IPV/Hib. In addition, caregivers in urban areas showed more concern about the vaccine price (P = 0.010) and immunization schedule (P = 0.022) in regard to vaccinating children. CONCLUSIONS: The DTaP-IPV/Hib vaccine coverage rate in Hainan Province remains low. Factors such as lower socioeconomic status, cultural beliefs, concerns about vaccine safety, and cost may hinder caregivers from vaccinating their children. Further measures, such as health education campaigns to raise knowledge and awareness, and encouragement of domestic vaccine innovation, which would reduce out-of-pocket costs, could be implemented to improve the coverage of DTap-IPV/Hib vaccination.

Extreme Temperature Exposure and Risks of Preterm Birth Subtypes Based on a Nationwide Survey in China.

BACKGROUND: Previous studies have reported that ambient temperature may affect perinatal outcomes. However, whether extreme temperature affects the risk of preterm birth (PTB) remains controversial. Studies on the associations of extreme temperature with PTB subtypes are lacking. OBJECTIVES: We aimed to investigate the associations of extreme climate events with the risks of PTB and its subtypes, discerning possible modifiers. METHODS: Data on all singleton deliveries were obtained from the China Labor and Delivery Survey (CLDS), a nationwide investigation implemented in 2015 and 2016. PTB was defined as gestational weeks <37 and then categorized as early (24-34 wk) and late PTBs (35-36 wk), and clinical subtypes [spontaneous PTB, preterm premature rupture of the fetal membranes (PPROM), iatrogenic PTB]. Ambient temperature data were provided by the China National Weather Data Sharing System. Five heat indexes and five cold indexes were used to define heat waves and cold spells. Generalized linear mixed models with a random term by hospital unit were used to assess the associations of short-term prenatal extreme temperature exposure. The Cox proportional hazard regression model was applied to assess the nonlinear associations of low- or high-temperature exposure at the whole and different trimesters of pregnancy with the risk of PTB. Stratified analyses were conducted to assess the possible modification by geographic region and fetal sex. RESULTS: A total of 70,818 singleton births from 96 hospitals in China were included, among which 4,965 (7.01%) were PTBs. Exposure to extreme cold events 1 wk before delivery was associated with an increased PTB risk, with an adjusted odds ratio (aOR) [95% confidence intervals (CIs)] of 1.07 (95% CI: 1.04, 1.10) and 1.06 (1.04, 1.09) for the total days when the daily average temperature below the fifth percentile (fifth-days) and the 10th percentile (10th-days), 1.18 (1.04, 1.34) for the cold spells when the daily average temperature below the fifth percentile for two consecutive days (fifth-2D), 1.09 (1.03, 1.16) and 1.12 (1.06, 1.19) for the cold spells when the daily average temperature below the 10th percentile for three and two consecutive days (10th-3D and 10th-2D), respectively. Results of extreme temperature exposure during 2 weeks before delivery showed similarly significant associations. The association between cold spells and PTB tended to be stronger for late PTB than for early PTB. Cold spells were mainly associated with spontaneous PTB and late PPROM. A stratified analysis indicated that pregnant women in western and northern regions tended to be more sensitive to cold spells, and pregnant women with a female fetus appeared to be at a higher risk of PTB when exposed to cold spells. Pregnant women in late pregnancy were more susceptible to extreme temperatures. No significant or stable association was found between heat waves and preterm birth. DISCUSSION: Exposure to cold spells was associated with an increased risk of PTB, especially late, spontaneous PTB and PPROM. The associations appeared to be more pronounced in the north and west regions and in pregnancies with female fetuses. https://doi.org/10.1289/EHP10831.

Prenatal exposure to fine particulate matter and newborn anogenital distance: a prospective cohort study.

BACKGROUND: Considerable attention has been paid to reproductive toxicity of fine particulate matter (PM2.5). However, the relationship between prenatal PM2.5 exposure and anogenital distance (AGD) has not been well studied. We aim to investigate the potential effects of prenatal exposure to PM2.5 on newborn AGD. METHODS: Prenatal PM2.5 exposure of 2332 participates in Shanghai (2013-2016) was estimated using high-performance machine learning models. Anoscrotal distance (AGDas) in male infants and anofourchette distance (AGDaf) in female infants were measured by well-trained examiners within 3 days after birth. We applied multiple linear regression models and multiple informant models to estimate the association between prenatal PM2.5 exposure and AGD. RESULTS: Multiple linear regression models showed that a 10 µg/m3 increase in PM2.5 exposure during full pregnancy, the second and third trimesters was inversely associated with AGDas (adjusted beta = - 1.76, 95% CI: - 2.21, - 1.31; - 0.73, 95% CI: - 1.06, - 0.40; and - 0.52; 95% CI: - 0.87, - 0.18, respectively) in males. A 10 µg/m3 increase in PM2.5 exposure during the full pregnancy, the first, second, and third trimesters was inversely associated with AGDaf (adjusted beta = - 4.55; 95% CI: - 5.18, - 3.92; - 0.78; 95% CI: - 1.10, - 0.46; - 1.11; 95% CI: - 1.46, - 0.77; - 1.45; 95% CI: - 1.78, - 1.12, respectively) in females after adjusting for potential confounders. Multiple informant models showed consistent but slightly attenuated associations. CONCLUSION: Our study observed a significant association between gestational PM2.5 exposure during pregnancy and shortened AGD in newborns, and provided new evidence on potential reproductive toxicity of prenatal PM2.5 exposure.

Effects of a Smartphone-Based Out-of-Hospital Screening App for Neonatal Hyperbilirubinemia on Neonatal Readmission Rates and Maternal Anxiety: Randomized Controlled Trial.

BACKGROUND: Neonatal hyperbilirubinemia is one of the leading causes of neonatal readmission-especially severe hyperbilirubinemia and its complications-and it influences disease burden as well as neonatal and maternal health. Smartphones have been shown to have satisfactory accuracy in screening neonatal bilirubin levels, but the impact of this technology on neonatal health care service and maternal health outcomes is still unknown. OBJECTIVE: The aim of this study was to evaluate the impact of a smartphone-based out-of-hospital neonatal jaundice screening program on neonatal readmission rates for jaundice and related maternal anxiety. METHODS: This was a 2-arm, unblinded, randomized controlled trial with 30 days of intervention and follow-up periods. From August 2019 to August 2020, healthy mother-infant dyads were recruited on-site from 3 public hospitals in Hainan, China. Intervention group mothers used the smartphone app to routinely monitor neonatal jaundice at home under the web-based guidance of pediatricians. Control group participants received routine care. The primary study outcome was the neonatal readmission rate due to jaundice within 30 days of the first hospital discharge. The secondary outcome was the maternal anxiety score associated with neonatal jaundice. The data were collected through a self-assessed questionnaire. All participants were included in the analysis (intention-to-treat). RESULTS: In this study, 1424 mother-infant dyads were recruited, comprising 1424 mothers and 1424 newborns. The median age of the mothers was 29 (IQR 26-32) years, and there were 714 (50.1%) male neonates. These mother-infant dyads were randomly assigned to the intervention group and the control group, with 712 dyads in each group; only 1187 of these dyads completed the follow-up. We found that the adjusted 30-day neonatal readmission rate due to jaundice reduced by 10.5% (71/605, 11.7% vs 141/582, 24.2%; 95% CI 5%-15.9%; odds ratio 0.4, 95% CI 0.3-0.5; P<.001) and the relevant maternal anxiety mean score decreased by 3.6 (95% CI -4.4 to -2.8; ß=-3.6, 95% CI -4.5 to -2.8; P<.001) in the intervention group compared to those in the routine care group. CONCLUSIONS: Our study shows that the smartphone-based out-of-hospital screening method for neonatal hyperbilirubinemia decreased the neonatal readmission rate within 30 days from the first discharge and improved maternal mental health to some degree, thus demonstrating the usefulness of this screening app for follow-up in pediatric care. TRIAL REGISTRATION: China Clinical Trial Registration Center, ChiCTR2100049567; http://www.chictr.org.cn/showproj.aspx?proj=64245.

The role of individual service and team-based service price in the online environment: A view from the price difference.

Different from the traditional medical market, the online medical market allows physicians considerable discretion in setting prices of their services, which is beginning to be paid close attention to. Physicians face a challenge with the introduction of various service styles. Guided by transaction utility theory and price fairness, this study aims to investigate the influence of pricing strategy on service demands from the price difference perspective by focusing on two typical service models: individual service and team-based service. Moreover, team characteristics (response speed and team size) are also considered. The data collection was done in March 2018 and repeated in May 2018, and physicians who provide both individual service and team-based services are included in our study. Finally, a dataset consisting of 1,100 teams with 1,100 physician leaders from 14 departments such as obstetrics and gynecology department were collected from an online medical platform in China. Empirical results support most of our hypotheses. A negative influence of team-based price was observed. As a substitute service, a higher individual service price will make patients turn to team-based service. Moreover, individual service prices negatively moderated the relationship between team-based service prices and demands. By calculating the price difference between the individual service price and the team-based service price, we found a negative role of the price difference affecting patient purchase decisions. Although we did not find a significant effect of team size, a quick response can attract more patients. Price fairness provides a proper framework for understanding pricing strategy in individual and team-based service in an online environment. Understanding the effects of prices from a price difference perspective has both theoretical and practical contributions. Specifically, this study contributes to knowledge on price fairness, online medical platforms, and virtual teams, and provides management suggestions.

Development and validation of a maternal anxiety for neonatal jaundice scale in China.

BACKGROUND: Maternal anxiety induced by neonatal jaundice has adverse effects on maternal and infant health, but there was no specific tool to identify the anxiety level of mothers. This study aims to develop a Maternal Anxiety for Neonatal Jaundice Scale (MANJS) and to validate it in the target population. METHODS: An initial 11-items MANJS was developed through literature review, expert panel consultation, and a pilot-test. Subsequently, mothers of neonates with jaundice were recruited from the Maternal and Child Health Hospital of Hainan Province, China, from June to December 2018, for a formal questionnaire survey. Based on the data collected, the scale was validated for construct validity, convergent validity, discriminant validity, content validity, and internal consistency reliability after the items screening. RESULTS: The reliability and validity of MANJS were validated in 1127 mothers of jaundiced neonates. After the item with cross-loadings was removed using exploratory factor analysis, MANJS consisted of two dimensions and 10 items, with a cumulative variance contribution of 74.36% and factor loadings above 0.6 for all items. The confirmatory factor analysis identified three items with cross-factor loading or error correlation and then they were removed orderly. The further confirmatory factor analysis showed a good construct validity for the 7-item MANJS, with standardized root mean square residual (SRMR) = 0.029, root mean square error of approximation (RMSEA) = 0.068, comparative fit index (CFI) = 0.961, Tucker-Lewis index (TLI) = 0.937, incremental fit index (IFI) = 0.961, normed fit index (NFI) = 0.954, goodness of fit index (GFI) = 0.998, adjusted goodness of fit index (AGFI) = 0.996, respectively. The average variance extracted values (AVE) of the two factors were 0.80 and 0.72, and the combined reliability (CR) were 0.94 and 0.88, respectively. Cronbach's alpha was 0.90 for the MANJS, and split-half reliability was 0.72. CONCLUSIONS: MANJS was demonstrated to have satisfactory reliability and validity in evaluating maternal anxiety caused by neonatal jaundice among Chinese postpartum women.

Serum vitamin D status among healthy children in Hainan, South China: a multi-center analysis of 10,262 children.

Background: There are limited data regarding the prevalence and risk factors relating to vitamin D deficiency (VDD) in children of Hainan, a tropical city with abundant sunlight in China. To gather and analyze the serum VD levels of healthy children in Hainan, so as to understand their VD nutritional status and improve the representative data of VD nutritional status in south China. Methods: Children who presented to the outpatient clinic for physical examination at 4 hospitals in the Hainan Province from 2012 to 2020 were enrolled in this study. The serum 25-hydroxyvitamin D (25-OHD) levels was analyzed. 25-OHD levels <50 nmol/L is considered VDD, 50-75 nmol/L is vitamin D insufficiency (VDI), and ≥75 nmol/L is VD sufficient (VDS). Results: The average serum 25-OHD level was 94.63±49.99 nmol/L [95% confidence interval (CI): 93.67-95.60]. VDD was detected in 13.98% of participants (1,435 cases), VDI was detected in 30.60% of participants (3,140 cases), and 55.42% presented with VDS (5,687 cases). The average 25-OHD level of boys was significantly higher than that of girls (t=3.67, P<0.001). The average serum 25-OHD levels in the following age groups 0-1, 1-3, 3-7, 7-14, and 14-18 years were 105.92±57.39, 100.55±53.22, 86.35±39.19, 73.61±34.21, and 54.97±19.19 nmol/L, respectively. These results suggested that with an increase in age, the 25-OHD levels decreased. The average 25-OHD levels of children with a body mass index (BMI) <85th percentile were significantly higher than that of children in the overweight and obese group (F=7.393, P=0.001). Conclusions: A certain proportion of all age groups showed vitamin D deficiency and insufficiency in Hainan. A formal recommendation for vitamin D supplementation should be considered, especially in autumn and winter seasons for children over 7 years old, and in those with BMI ≥85th percentile or BMI ≥95th percentile.

Associations between prenatal exposure to polybrominated diphenyl ethers and physical growth in a seven year cohort study.

Although evidence suggests that prenatal exposure to polybrominated diphenyl ethers (PBDEs) alter offspring's physical growth, most studies rely upon physical growth at a single timepoint, and little is known regarding their longitudinal effects over time. In the current study, we determined the associations between prenatal PBDEs exposure and child physical growth by following up 207 mother-child pairs from the Laizhou Wan Birth Cohort (LWBC) from pregnancy until the children were seven years old. Child physical growth including weight, height, and body mass index (BMI) was assessed at birth, and at one, two and seven years of age. Prenatal exposure to PBDEs was quantified by measuring eight PBDE congeners (BDE-28, BDE-47, BDE-85, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) in maternal serum samples collected upon hospital admission for delivery. Linear mixed models were applied to examine the associations between prenatal PBDEs exposure and repeated measures of child physical growth, and to determine whether these associations were modified by child's sex. Our findings indicated that BDE-28, BDE-85, BDE-153, BDE-183, and Σ7PBDEs were positively associated with child weight z-score; and that BDE-28, BDE-47, BDE-85, BDE-99, BDE-153, and Σ7PBDEs were positively associated with child height z-score. In addition, these associations were modified by the child's sex as reflected by pronounced positive associations among boys, while negative associations were noted among girls. In conclusion, our findings indicated the sex-specific associations between prenatal PBDE exposures and child physical growth during the first seven years of life.

Surveys of Drosophila suzukii (Diptera: Drosophilidae) and Its Host Fruits and Associated Parasitoids in Northeastern China.

Spotted-wing drosophila, Drosophila suzukii (Matsumura), is a worldwide quarantine pest that is currently undergoing a rapid range expansion in the Americas, Europe, and parts of Africa. It feeds and breeds on soft-skinned fruits such as raspberries, blueberries, and cherries, and can cause significant economic losses to fruit production. This study investigated the occurrence of D. suzukii and its wild host fruits and parasitoids in Liaoning, Northeast China for the first time. Sentinel traps were used to monitor D. suzukii adults, and suspected fruits were collected weekly in four different locations (Wafangdian, Faku, Fengcheng, and Shenyang). The results showed that D. suzukii were distributed in the sweet soft-skinned fruit-production areas of Liaoning, and raspberry was the most infested fruit. During the field survey, four species of wild berries from non-crop habitats were found infested by D. suzukii, and two species of parasitoids (Leptopilina japonica and Asobara japonica) were collected. D. suzukii adult-population dynamics throughout the survey period (June to October) were similar in different survey locations; adult fly populations increased and peaked in August, and then declined until the fly was no longer detectable in October.

Exosomal miR-122 promotes adipogenesis and aggravates obesity through the VDR/SREBF1 axis.

OBJECTIVE: This study examined the effects of miR-122-enriched exosomes on the expression of vitamin D3 receptor (VDR) and sterol regulatory element-binding transcription factor 1 (SREBF1) and their roles during adipogenesis. METHODS: The roles of miR-122, SREBF1, and VDR were investigated during adipogenesis. The relationships between VDR and miR-122 or SREBF1 were assessed by dual-luciferase reporter and chromatin immunoprecipitation assays. The potential role of miR-122/VDR/SREBF1 was evaluated in high-fat diet-induced obese male mice. RESULTS: High levels of miR-122 were found only in adipose tissue-derived exosomes (Exo-AT) and Exo-AT-treated cells. Overexpression of miR-122 promoted adipogenesis, and inhibition of miR-122 prevented adipogenesis by regulating VDR, SREBF1, peroxisome proliferator-activated receptor gamma, lipoprotein lipase, and adiponectin. Knockdown of Srebf1 or overexpression of VDR could inhibit adipogenesis. However, exosomal miR-122 could reverse their inhibitory effects. The dual-luciferase reporter assay and chromatin immunoprecipitation assays confirmed that VDR was a direct target of miR-122. It could bind to the BS1 region of the SREBF1 promoter and inhibit SREBF1 expression. Moreover, miR-122 inhibition could alleviate obesity in high-fat diet-induced obese male mice, possibly through upregulating the VDR/SREBF1 axis. CONCLUSION: MiR-122-enriched Exo-AT promoted adipogenesis by regulating the VDR/SREBF1 axis.

Mediastinal and subglottic hemangioma in an infant: a case report and literature review.

We performed a retrospective analysis of the clinical manifestations, laboratory and imaging examinations, treatment, and prognosis of a male infant who was diagnosed with mediastinal and subglottic hemangioma in our hospital. The clinical features of this patient were coughing, wheezing, and dyspnea. Enhanced computed tomography of the neck and chest showed a diffuse abnormality in the right-upper mediastinum. He was diagnosed with a hemangioma after a physical examination combined with bronchoscopy. The clinical symptoms were relieved by oral propranolol. We also investigated the clinical characteristics, treatment, and prognosis of mediastinal and subglottic hemangioma in infants in the previous literature, and searched for case reports of this disease in China and in other countries. We only identified three previous cases of mediastinal and subglottic hemangioma in infants, indicating that this condition is rare. In the proliferative stage, surrounding organs and tissues are compressed, which can be life-threatening. Most of these children develop wheezing, shortness of breath, dyspnea, cyanosis, and other symptoms within 2 months. Enhanced computed tomography and magnetic resonance imaging combined with soft bronchoscopy can confirm the diagnosis of this disease, and oral propranolol achieves a favorable effect.

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.

Epidemiologic characteristics of birth defects in the Hainan Province from 2000 to 2010, China.

BACKGROUND: Although the prevalence of congenital malformations is high in China, little information is available on the Hainan Province. METHODS: Data used in this study were collected from 2000 to 2010 by monitoring newborns (including both live births and stillbirths) in the Hainan Province. Comparison analyses were conducted by performing χ(2) tests. RESULTS: The data showed an increasing temporal trend of the birth defect prevalence in the Hainan Province; however, the rate of birth defects changed over time. CONCLUSION: The Hainan Province is confronted with the challenge to reduce the prevalence of birth defects. Interventions should focus on the rural areas where a higher prevalence of birth defects is observed.

Hepatitis B surface antigen prevalence among 12,393 rural women of childbearing age in Hainan Province, China: a cross-sectional study.

BACKGROUND: Hepatitis B virus (HBV) infection is highly endemic in China and it threats human health seriously. The hepatitis B surface antigen (HBsAg) prevalence among women of childbearing age plays an important role in mother to child transmission of HBV, as 30%~50% of chronic carriers can be attributed to maternal-infantile transmission. However, there are few studies which have reported on the prevalence of HBsAg among women of childbearing age in China. This study aimed to determine the prevalence of HBsAg and its associated risk factors among rural women of childbearing age in Hainan, which is the highest hepatitis B virus endemic province in China. METHODS: A cross-sectional, population-based study, which included 12,393 rural women aged 15~49 years, enrolled by a multistage stratified cluster sampling, was carried out in Hainan province, China, from November 2007 to December 2008. Blood samples were obtained from each study participant, and screened for HBsAg. RESULTS: The overall HBsAg prevalence of childbearing age women was 9.51%. Risk factors for HBsAg positivity among rural women were: lower education level (OR=1.206), lower family monthly income (OR=1.233), having an HBsAg-positive family member (OR=1.300), without an immunization history (OR=1.243), tattooing (OR=1.190), body piercing (OR=1.293), vaginoscopy history (OR=1.103) and history of induced abortion (OR=1.142). CONCLUSIONS: There is a high HBsAg seroprevalence rate among rural women of childbearing age in Hainan province. Hence, it is necessary to take preventive measures to reduce the seroprevalence of HBsAg and to control its associated risk factors.