There is growing scientific evidence supports a link between increased childhood adiposity and early onset of puberty in girls worldwide in recent decades. However, the data from Chinese girls remain ...ambiguous. The aims of this study were to estimate the puberty milestones and examine attainment of puberty associated with obesity and central obesity in Chinese Han schoolgirls.
The cross-sectional school-based study examined 2996 Han schoolgirls aged 9 to 19 years from 6 provinces in China. Trained clinicians assessed the girls for height, weight, waist circumference, Tanner stages of breast and pubic hair development, and menarcheal status. We classified girls as normal weight, overweight, or obese based on BMI, and as normal weight or central obese based on the waist-height ratio, then estimated and compared median age at a given Tanner stage or greater by weight class using Probit models.
The median age at menarche was 12.36 years. The median ages at breast stages(B) 2 through 5 were 10.03, 11.38, 13.39, and 15.79 years, respectively, and at pubic hair stages(PH) 2 through 5 were 11.62, 12.70, 14.38, and 16.92 years, respectively. Girls from urban areas experienced menarche, B3 and B4 stages, and PH3 through PH5 stages earlier. Girls with central obesity and overweight/obesity reached puberty earlier at almost every Tanner stage of breast and pubic hair than normal girls. Girls with obesity developed PH2 and PH3 earlier than their overweight peers. However, we did not find any significant differences between girls with overweight and obesity at all stages of breast development.
Childhood obesity, including both overweight/obesity and central obesity, is associated with earlier attainment of puberty in Chinese Han schoolgirls.
Extreme pre-pregnancy body mass index (BMI) values have been associated with reduced fecundability and prolonged time to pregnancy in previous studies. However, the effect in fertile couples is ...unclear.
This study aimed to evaluate the association between pre-pregnancy BMI and fecundability, measured as time to pregnancy (TTP), among couples that achieved pregnancy within 1 year.
This was a retrospective cohort study of 50,927 couples wishing to conceive, enrolled in the National Free Preconception Health Examination Project (NFPHEP) in Chongqing, China, during 2012-2016. Participants' weight and height were measured by NFPHEP-trained preconception guidance physicians. TTP measured in months was used to determine subfecundity (TTP >6 months). The strength of association between BMI and TTP/subfecundity was measured with fecundability odds ratios (FOR)/odds ratios (OR) and their corresponding 95% confidence intervals (CI), calculated with Cox and logistic regression analysis. We used restricted cubic spline regression (RCS) to test the observed FOR trends.
Compared to women with normal BMI, women with pre-pregnancy overweight/obesity had longer TTP (FOR = 0.96, 95% CI: 0.94-0.99) and increased risk of subfecundity (OR = 1.08, 95% CI: 1.00-1.17). There was no association between TTP and male BMI. RCS trends varied when data were stratified by male pre-pregnancy BMI, with the greatest change detected in pre-pregnancy underweight men.
Pre-pregnancy overweight/obesity was associated with longer TTP and subfecundity among women who became pregnant within 1 year; this effect was likely mediated by their partners' pre-pregnancy BMI. These findings indicate that BMI could affect fecundability, independently of affecting the risk of sterility. Advice on weight management and maintaining healthy weight should be included in couples' preconception guidance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
Little is known on the co-occurrence and heterogeneity of child sexual abuse (CSA) or health risk behavior (HRB) prevalence nor the associations among the victims.
Objectives
To ...detect the prevalence and subgroups of adolescents reporting CSAs or HRBs, and to examine the association between the subgroups.
Methods
Participants were secondary school students in a national survey in China (
N
= 8746). Self-reported CSA and HRB experiences were collected through a computer assisted questionnaire. Prevalence and confidence intervals were calculated. Multigroup latent class analysis (LCA) was used to examine latent subgroups of CSA and HRB. Dual latent class regression analysis was used to examine the association between CSA and HRB classes.
Results
A total of 8746 students participated in our study. The prevalence of having ever experienced any of the reported seven CSA items was 12.9%. The preferred LCA model consisted of a three-class CSA latent variable, i.e. “Low CSAs”(95.7% of the total respondents), “Verbal or exhibitionism CSAs”(3.3%), and “high multiple CSAs” (1.1%); and a three-class HRB latent variable, i.e. “Low HRBs”(70.5%), “externalizing HRBs” (20.7%), and “internalizing HRBs” (8.7%). Students in the “Verbal or exhibitionism CSAs” or “high multiple CSAs” classes had higher probabilities of being in “externalizing HRBs” or “internalizing HRBs” classes. The probabilities were higher in “high multiple CSAs” class(male externalizing OR 4.05, 95%CI 1.71–9.57; internalizing OR 11.77, 95%CI 4.76–29.13; female externalizing OR 4.97, 95%CI 1.99–12.44; internalizing OR 9.87, 95%CI 3.71–26.25) than those in “Verbal or exhibitionism CSA”(male externalizing OR 2.51, 95%CI 1.50–4.20; internalizing OR 3.08, 95%CI 1.48–6.40; female externalizing OR 2.53, 95%CI 1.63–3.95; internalizing OR 6.05, 95%CI 3.73–9.80).
Conclusions
Prevalence of CSA items varies. Non-contact CSAs are the most common forms of child sexual abuse among Chinese school students. There are different latent class co-occurrence patterns of CSA items or HRB items among the respondents. CSA experiences are in association with HRB experiences and the associations between latent classes are dose-responded. Multi-victimization has more significantly negative effects. The results could help identify high-risk subgroups and promote more nuanced interventions addressing adverse experiences and risk behaviors among at-risk adolescents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
Reproductive tract infections can cause serious adverse outcomes for pregnant women such as spontaneous abortion and preterm birth. However, it is unclear whether maternal ...reproductive tract infection before pregnancy would also be related to any adverse pregnancy outcomes. This study aims to investigate the association of maternal preconception reproductive tract infections with subsequent adverse pregnancy outcomes.
Methods
A retrospective cohort study was conducted in the Chongqing Municipality of China between April 2010 and December 2016. A total of 57,586 women (57,708 pregnancies) from all 39 counties of Chongqing who participated in the National Free Preconception Health Examination Project were included. They all took preconception examinations for gonorrhea, chlamydia, trichomoniasis, syphilis, bacterial vaginosis and candidiasis before pregnancy within one year. Primary outcomes included spontaneous abortion (< 28 weeks gestation), preterm birth (< 37 weeks gestation), macrosomia and low birthweight.
Results
Of the 57,708 pregnancies, 2438 (4.22%) had at least one type of reproductive tract infections. Compared with women who were not infected with any reproductive tract infection before pregnancy, women with reproductive tract infections had a higher rate of spontaneous abortion (7.88% vs. 5.62%, p < 0.001). After analyzing by each infection, there were few significant associations between pre-pregnancy infections and adverse outcomes. Preconception syphilis infection was significantly associated with increased odds of spontaneous abortion (aOR = 2.07, 95%CI 1.50–2.85), induced abortion/labour due to medical reasons (aOR = 1.60, 95%CI 1.01–2.54) and preterm birth (aOR = 1.60, 95%CI 1.12–2.30) after adjusting for potential confounders. Preconception trichomoniasis was intended to relate to a higher risk of spontaneous abortion (aOR = 1.65, 95%CI 1.01–2.71), but its impact seemed to be attributed to its co-infection with other RTIs. Women who were chlamydia or bacterial vaginosis positive before pregnancy showed higher odds of macrosomia (aOR = 2.00, 95% CI 1.07–3.74 for chlamydia; aOR = 1.58, 95% CI 1.06–2.34 for bacterial vaginosis). Preconception bacterial vaginosis might also be associated with higher risks of very preterm birth (aOR = 2.16, 95%CI 1.23–3.78) and large for gestational age (aOR = 1.36, 95%CI 1.02–1.81).
Conclusions
Women with infections of the genital tract before pregnancy might also have increased risks of subsequent adverse outcomes including spontaneous abortion, preterm birth and macrosomia.
The rockburst phenomenon occurs in dry red sandstone under high
in situ
stress, and the rockburst effect is weaker for a water-bearing rock. The rockburst effect on red sandstone with different water ...contents is analyzed in this paper. A true triaxial testing machine is used to conduct the loading, and acoustic emission recording equipment and a high-speed camera are used to monitor the acoustic signal inside the rock and the rock-caving situation throughout the entire process in order to analyze the characteristics of the acoustic emissions and the ejection form of the rockburst. The results show that rockburst occurs in dry red sandstone and 50% saturated red sandstone but not in saturated red sandstone. The phrase characteristics of the stress–strain curve of the dry rock vary more significantly than those of the water-bearing rock, and the elastic strain energy inside the rock decreases gradually as the water content increases. The double peak of the acoustic emissions curve occurs during the failure process of the dry rock and gradually transitions to a stepped pattern as the water content increases. The ejected fragments of dry red sandstone during the rockburst are abundant and large. The true triaxial test results illustrate the characteristic effect of the rockburst on red sandstone with different water contents, reveal the failure mode and ejection characteristics of red sandstone with different water contents, and demonstrate the influence of the water content on the rockburst characteristics of red sandstone. The results of this study provide a theoretical reference for the study of the rockburst mechanisms of similar hard rocks.
Maternal folate may not reach an optimal level to prevent neural tube defects if supplementation commenced post-conception or took place pre-conception only. Our study aimed to investigate the ...continuation of folic acid (FA) supplementation from pre-conception to post-conception during peri-conceptional period and to examine its differences in FA supplementation between the subgroups taking the initiation timing into consideration.
This study was conducted in two community health service centers in Jing-an District of Shanghai. Women accompanying their children to pediatric health clinics of the centers were recruited and asked to recall information concerning their socioeconomic and previous obstetric characteristics, utilization of healthcare and FA supplementation before and/or during pregnancy. The continuation of FA supplementation during peri-conceptional period were categorized into three subgroups: Supplementing with FA pre- and post-conception; supplementing with FA preconception only or post-conception only; no FA supplements pre-conception and post-conception. The relationship between FA continuation and couples' characteristics were examined as setting the first subgroup as the base reference.
Three hundred and ninety-six women were recruited. Over 40% of the women started FA supplementation after conception and 30.3% of them supplemented with FA from pre-conception to the first trimester of their pregnancy. Compared to this one-third of participants, women who didn't supplemented with any FA during peri-conceptional period were more likely to have no utilization of pre-conception healthcare (Formula: see text= 2.47, 95% Formula: see text: 1.33-4.61) or antenatal care (Formula: see text= 4.05, 95% Formula: see text: 1.76-9.34), or who had a lower family socioeconomic status (Formula: see text= 4.36, 95% Formula: see text: 1.79-10.64). Women who supplemented with FA pre-conception only or post-conception only were more likely to have no utilization of pre-conception healthcare (Formula: see text= 2.94, 95% Formula: see text: 1.79-4.82), or to have no previous pregnancy complication (Formula: see text=1.80, 95% Formula: see text: 0.99-3.28).
Over two-fifth of the women started FA supplementation and only one-third of them had an optimal supplementation from pre-conception to the first trimester. Maternal utilization of healthcare before or during pregnancy together with maternal and paternal socioeconomic status may play a role in the continuation to FA supplementation pre- and post-conception.
In this study, we investigated the association between altered methylation in the maternal placenta and hyperglycaemia and explored the epigenetic mechanisms underlying gestational diabetes mellitus ...(GDM). Reduced representation bisulphite sequencing (RRBS) and RNA sequencing (RNA-seq) were performed on placental tissues obtained from women with GDM and healthy controls. Further, pyrosequencing, correlation analyses, and linear regression analyses were performed to valuate relationships between aberrantly methylated-differentially expressed genes and clinical parameters. The EMBOSS and JASPAR databases were used for a computational analysis of CpG islands and transcription factor-binding sites in the TRIM67 promoter region. A CpG island with a length of 264 bp in the placental TRIM67 promoter region in the GDM group exhibited significant hypermethylation at four CpG sites. The hypermethylation of the TRIM67 promoter region in the maternal placenta showed a significant, positive correlation with the 1 h and 2 h oral glucose tolerance test (OGTT) values and a negative correlation with lipoprotein(a). Placental DNA methylation levels in the TRIM67 promoter region were markedly elevated in GDM and were associated with blood glucose and lipid levels during healthy pregnancy.
Manganese (Mn) is an essential element in humans but its effect on semen quality is unclear. This study therefore aimed to assess the effects of Mn on semen quality in healthy men with no ...occupational exposure to Mn.
Semen samples were obtained from healthy Chinese men 20-59 years old who were recruited from six provinces in China. Individuals with urogenital tract diseases, tuberculosis, or occupational exposure to heavy metals were excluded. A questionnaire survey was conducted, and the external genitalia, semen quality, and serum Mn levels were examined.
A total of 1,179 volunteers were enrolled in this study. The median serum Mn concentration was 8.2 μg/L (25th percentile (P25)=3.7 μg/L, P75=16.2 μg/L). After adjusted area (six provinces), abstinence interval, season, registered residence, age of subjects, education level, income, smoking, and drinking, the risk of teratospermia was increased at serum Mn concentrations >19.40 μg/L (P80) group, with an adjusted odds ratio of 2.27 (95% confidence interval: 1.18-4.37).
High serum Mn levels appeared to have harmful effects on sperm morphology and motility among healthy men with no occupational exposure to Mn.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
Reproductive tract infection has become a major public health issue all over the world for its high and growing prevalence. It can cause adverse pregnancy outcomes in pregnant ...women and their foetuses. This study aimed to investigate the trends and risk factors of the prevalence of reproductive tract infections among women who prepared to conceive in the Chongqing Municipality (China) from 2012 to 2016.
Methods
A multi-center cross-sectional study was conducted between January 2012 and December 2016. Women aged 20–49 years who intended to get pregnant were recruited for this study. All participants underwent preconception examination, which included testing for
Neisseria gonorrhoeae
,
Chlamydia trachomatis
,
Trichomonas vaginalis
, syphilis, bacterial vaginosis and candidiasis according to the national diagnostic standard. A total of 439,372 women with testing results for all six types of reproductive tract infections were included in our final analyses. Logistic regression and factor analysis were used to determine the possible sociodemographic factors associated with prevalence trends.
Results
In our study, the overall positive rate of RTIs among the 439,372 women of reproductive age was 5.03%. Candidiasis was the most common infection in our population (2.47%), followed by bacterial vaginosis (1.28%), syphilis (0.73%),
T. vaginalis
(0.49%),
C. trachomatis
(0.20%) and
N. gonorrhoeae
(0.06%). The prevalence of reproductive tract infections was highest among women aged 35 years and above, with a primary or lower education level, history of pregnancy, delivery, induced abortion, or spontaneous abortion. From 2012 to 2016, the trend of the overall prevalence of reproductive tract infections was V-shaped, decreasing steadily from 2012 to 2015, with a slight rise in 2016. Our results suggest that the distribution change of age, education level, gravidity, parity, and history of induced abortion influenced this trend.
Conclusion
Since the number of high-risk women who intend to become pregnant is growing in the Chongqing Municipality, pre-conception positive preventions including health education, regular screening, and timely treatment of reproductive tract infections are needed to prevent the impact of reproductive tract infections on maternal health and infant safety.
ObjectiveTo investigate the association between maternal pregestational blood glucose level and adverse pregnancy outcomes.DesignRetrospective cohort study.SettingThis study was conducted in the ...Chongqing Municipality of China between April 2010 and December 2016.ParticipantsA total of 60 222 women (60 360 pregnancies) from all 39 counties of Chongqing who participated in the National Free Preconception Health Examination Project and had pregnancy outcomes were included.Primary outcome measuresAdverse pregnancy outcomes included spontaneous abortion, induced abortion or labour due to medical reasons, stillbirth, preterm birth (PTB), macrosomia, large for gestational age, low birth weight (LBW) and small for gestational age.ResultsOf the 60 360 pregnancies, rates of hypoglycaemic, normoglycaemia, impaired fasting glycaemia (IFG) and diabetic hyperglycaemic before conception were 5.06%, 89.30%, 4.59% and 1.05%, respectively. Compared with women with normoglycaemia, women with pregestational glucose at the diabetic level (≥7.0 mmol/L) might have a higher rate of macrosomia (6.18% vs 4.16%), whereas pregestational IFG seemed to be associated with reduced risks of many adverse outcomes, including spontaneous abortion, induced abortion due to medical reasons, PTB and LBW. After adjusting for potential confounders, pregestational diabetic hyperglycaemic was remained to be significantly associated with an increased risk of macrosomia (adjusted risk ratio 1.49, 95% CI 1.07 to 2.09). Abnormal maternal glucose levels before pregnancy (either hypoglycaemic or hyperglycaemic) seemed to have no significant negative effect on spontaneous abortion or induced abortion due to medical reasons.ConclusionAlthough without overt diabetes mellitus, women with once diabetic fasting glucose level during their preconception examinations could be associated with an increased risk for macrosomia. Uniform guidelines are needed for maternal blood glucose management during pre-pregnancy care to improve pregnancy outcomes.
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