[Current status of pubertal sexual characteristics development of 2 704 girls aged 6-18 years in Tongzhou District of Beijing].

Objective: To understand the current status of pubertal sexual characteristics development of girls aged 6-18 years in Tongzhou District of Beijing and to compare the differences in sexual characteristics development among girls characterized as thin, normal, overweight, and obese. Methods: A cross-sectional survey was conducted among 2 844 girls aged 6-18 years in Tongzhou District of Beijing from September 2022 to July 2023. The developmental stages of breast and pubic hair were assessed on site, and menarche status was inquired. Weight and height were measured. The girls were subsequently characterized into thin, normal, overweight and obese groups. Basic information (including family and personal history) was obtained through questionnaires. Probit probability unit regression was applied to calculate the age of each Tanner stage of sexual characteristics development and the age of menarche. The χ2 test was applied to compare the counting data between two or multiple groups. Results: A total of 2 844 girls were surveyed and 2 704 girls met the inclusion criteria, resulting in a valid response rate of 95.1%. Among these girls, 1 105 (40.9%) were aged 6-9 years, 1 053 (38.9%) were aged 10-13 years, and 546 (20.2%) were aged 14-18 years. The of height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and body mass index-for-age Z-score (BAZ) were 0.46(-0.23,1.16), 0.69(-0.16,1.67), and 0.67(-0.27,1.73) respectively. The prevalences of thin, overweight, and obesity were respectively 1.7% (45/2 704), 17.3% (467/2 704), and 19.9% (538/2 704), respectively. There were 45 girls in the thin group, 1 654 girls in the normal weight group, 1 005 girls in the overweight and obesity group. The age of Tanner stage breast 2 (B2), Tanner stage pubic hair 2 (P2), and menarche was 9.0 (95%CI 8.9-9.1), 10.5 (95%CI 10.4-10.6), and 11.4 (95%CI 11.3-1.5) years, respectively. The current status of breast and pubic hair maturity in girls with pubertal development shows that 64.6% (1 211/1 874) of these girls had breast development preceding pubic hair development, 32.4% (607/1 874) had concurrent breast and pubic hair development, and 3.0% (56/1 874) had pubic hairs development preceding breast development. The interval age between B2 and B5 was 4.7 (95%CI 4.6-4.8) years, between P2 and P5 was 4.5 (95%CI 4.4-4.6) years, and between B2 and menarche was 2.4 (95%CI 2.3-2.5) years. The ages of sexual characteristics development in overweight and obese groups were earlier than that in normal and thin groups. The ages of B2 in thin, normal, overweight, and obese groups were 10.0 (95%CI 9.5-10.6), 9.3 (95%CI 9.2-9.4), and 8.6 (95%CI 8.4-8.7) years, respectively. The age of menarche in thin, normal, overweight, and obese groups were 13.1 (95%CI 12.4-13.7), 11.6 (95%CI 11.4-11.7), and 11.1 (95%CI 11.0-11.2) years, respectively. The interval ages between B2 and B5 and between P2 and P5 was 4.5 and 4.1 years, respectively in the overweight and obese groups, and those in normal group and thin group was 4.7 and 4.5 years, 4.6 and 4.7 years, respectively. Conclusions: The ages of sexual characteristics development and menarche tend in Tongzhou District of Beijing to be earlier than that being reported of Beijing's survey 20 years ago. Girls characterized as overweight and obese not only start puberty at an earlier age than girls of normal weight, but also have a shorter developmental process.

[Updated growth standards for Chinese children under 7 years of age].

Objective: To construct growth standards for Chinese children under 7 years of age. Methods: Cross-sectional study design based on national representative data on children's growth and development in 2015 was used. Stratified cluster sampling method was used. A total of 83 628 healthy children aged 0-<7 years from 9 cities, including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, and Kunming, were investigated from June to November 2015, excluding those with adverse conditions that may impact the establishment of the growth standards. Weight, length (height) and head circumference were measured using unified measurement tools and measurement methods. The Lambda-Mu-Sigma method was employed to establish percentile and standard deviation score reference values of weight-for-age, length (height)-for-age, head circumference-for-age, weight-for-length (height) and body mass index (BMI)-for-age of the study population. The standard deviation score curves of the new-established growth standards were compared with the 2009 reference standards. Results: Reference values of percentile (P3, P10, P25, P50, P75, P90, P97) and standard deviation score (-3, -2, -1, 0,+1,+2,+3) of weight-for-age, length (height)-for-age, head circumference-for-age, weight-for-length (height) and BMI-for-age were obtained. Compared with the 2009 growth standards, the difference of weight at P50 was -0.1-0.4 kg, the difference of length (height) at P50 was 0.1-1.3 cm, the difference of head circumference at P50 was -0.2-0.2 cm, the difference of weight for length (height) at P50 was -0.2-0.5 kg, and the difference of BMI at P50 was -0.2-0.2 kg/m2. The main differences were as follows: weight for girls aged 5.0-<7.0 years was 0.4-0.6 kg higher at +2 s, height for boys and girls aged 2.0-<7.0 years was 0.4-1.4 cm higher at -2 s, and BMI for boys and girls aged 5.0-<7.0 years was 0.1-0.3 kg/m2 higher at +2 s than the 2009 reference standards. Conclusion: The newly established growth standards for Chinese children under 7 years of age that have achieved a minor revision to the 2009 reference standards, are recommended for nationwide use in growth monitoring and nutritional assessment.

[Reference values and growth curves of length for weight and head circumference for weight among Chinese newborns].

Objective: To establish the reference values and growth curves of length for weight and head circumference for weight among Chinese newborns in order to provide a reference for the assessment of body proportionality at birth. Methods: A cross-sectional design was applied. A total of 24 375 singleton live birth newborns with gestational ages at birth of 24+0 to 42+6 weeks were recruited from June 2015 to November 2018 from 13 cities including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, Kunming, Tianjin, Shenyang, Changsha, and Shenzhen, excluding those with maternal or newborn conditions that may impact the establishment of the reference values. The generalized additive model for location, scale, and shape was employed to establish reference values in terms of percentile and growth curves of length for weight and head circumference for weight for male and female newborns. The random forest machine learning method was employed to analyze the importance of variables between the established reference values in this study and the previous published weight/length, body mass index (BMI), ponderal index (PI), weight/head circumference, length/head circumference in the assessment of symmetrical and asymmetrical small for gestational age (SGA) newborns. Results: A total of 24 375 newborns with 13 197 male infants (preterm birth 7 042 infants and term birth 6 155 infants) and 11 178 female infants (preterm birth 5 222 infants and term birth 5 956 infants) were included in this study. The reference values in terms of percentile (P3, P10, P25, P50, P75, P90, P97) and growth curves of length for weight and head circumference for weight were obtained for male and female newborns with gestational ages of 24+0 to 42+6 weeks. The median birth lengths corresponding to the birth weights of 1 500, 2 500, 3 000, and 4 000 g were 40.4, 47.0, 49.3 and 52.1 cm for males and 40.4, 47.0, 49.2, and 51.8 cm for females, respectively; the median birth head circumferences were 28.4, 32.0, 33.2 and 35.2 cm for males and 28.4, 32.0, 33.1, and 35.1 cm for females, respectively. The differences of length for weight between males and females were minimum, with the difference range of -0.3 to 0.3 cm at P50; the differences of head circumference for weight between males and females were minimum, with the difference range of 0 to 0.2 cm at P50. Based on the match between birth length and birth weight for classifying symmetrical and asymmetrical SGA, length for weight and PI contributed the most, accounting for 0.32 and 0.25, respectively; based on the match between birth head circumference and birth weight, head circumference for weight and weight/head circumference contributed the most, accounting for 0.55 and 0.12, respectively; based on the match between birth length or head circumference with birth weight, head circumference for weight and length for weight contributed the most, accounting for 0.26 and 0.21, respectively. Conclusion: The establishment of the new standardized growth reference values and growth curves of length for weight and head circumference for weight among Chinese newborns are useful for clinical practice and scientific research.

[Analysis of vaginal microecology in 23 181 cases of the gynecological female outpatients].

Objective: To analyze the vaginal microecological status of vaginitis population and non-vaginitis population of gynecological female outpatients. Methods: A total of 30 265 women who visited the gynecological outpatient clinic of Beijing Obstetrics and Gynecology Hospital from December 2018 to December 2020 completed vaginal microecological examination. After removing the follow-up patients, 23 181 women were divided into group with symptoms and signs of vaginitis (6 697 cases) and group without symptoms and signs of vaginitis (16 484 cases), according to whether the women with symptoms and signs of vaginitis or not. And the vaginal microecological status of the two groups was compared and analyzed. Results: (1) The total detection rate of vaginitis in the initial women was 34.87% (8 083/23 181), of which 46.10% (3 087/6 697) in group with symptoms and signs of vaginitis and 30.31% (4 996/16 484) in group without symptoms and signs of vaginitis, nearly 1/3 of the gynecological outpatients without signs and symptoms of vaginitis had vaginitis. (2) Among the types of simple vaginitis, vulvovaginal candidiasis (VVC) was the most frequent in group with symptoms and signs of vaginitis (16.01%, 1 072/6 697), followed by aerobic vaginitis (AV; 12.83%, 859/6 697), with significant differences compared with group without symptoms and signs of vaginitis (all P<0.001). There were no statistical differences between the two groups of bacterial vaginosis (BV) and trichomonal vaginitis (TV), indicating that BV and TV were more likely to be neglected (all P>0.05). (3) The proportion of various combinations of vaginitis among 2 632 cases of mixed vaginitis were, in descending order: BV+AV, VVC+AV, BV+AV+VVC, AV+TV, AV+TV+BV, BV+VVC. (4) Microecological analysis of 15 098 cases diagnosed with non-vaginitis had normal flora (including those with normal flora and those with normal flora but decreased function) in 14 013 cases (92.81%, 14 013/15 098), abnormal flora in 429 cases (2.84%, 429/15 098) and the BV intermediate in 656 cases (4.34%, 656/15 098); this indicated that the vast majority of the microecological tests were normal in the vaginal microbiota of those without vaginitis. Conclusions: Microecological examination could diagnose multiple pathogenic infections at once, and is especially important as a guide for the definitive diagnosis of mixed vaginitis and vaginitis with atypical clinical symptoms. Vaginal infections such as BV and TV that are easily overlooked should be concerned.

[Dynamics of vaginal microbiota in women of reproductive age during the menstrual cycle].

Objective: To investigate the dynamic changes of vaginal microbiota in different phases of menstrual cycle in healthy Chinese women of childbearing age. Methods: A total of 11 healthy women of childbearing age with regular menstruation, who had physical examination in the Gynecology Clinic of Beijing Obstetrics and Gynecology Hospital from September to December 2020 were randomly selected as research subjects. Vaginal secretions were collected during menstrual phase (2nd-3rd day), mid-follicular phase (7th-8th day), and mid-luteal phase (21st-22nd day) for microbiota analysis through metagenomic sequencing. Results: (1) Vaginal microbiota species were the most diverse in menstrual phase and the least in follicular phase, observing dominant vaginal bacteria gradually changing to Lactobacillus from menstrual phase to follicular phase and then to luteal phase. (2) The dynamic evolution of vaginal microbiota from menstrual phase to follicular phase and then to luteal phase was divided into: no change in dominant bacteria, replacement of dominant bacteria, changes in the proportion of dominant bacteria, and recurrence of dominant bacteria (non-Lactobacillus-dominance appeared again in luteal phase after returning to normal Lactobacillus-dominance in follicular phase). (3) Prevotella, especially Prevotella_bivia, was significantly higher during menstrual phase. Conclusions: Healthy vaginal microbiota should be relatively stable, but also have the ability of dynamic change and self-recovery. Prevotella plays a central role among opportunistic pathogens in the vagina, whose function remains to be investigated.

[Risk factors of simple obesity in preschool children in nine cities of China].

Objective: To examine risk factors of simple obesity and their interaction in preschool children in China. Methods: A total of 63 292 preschool children aged 3-7 years selected by cluster random sampling in 9 cities of China, including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou and Kunming, were investigated from June to November in 2016. Based on the BMI-for-age cut off points of overweight and obesity for Chinese children aged 2-18 years, a total of 1 522 obese children (1 006 boys and 516 girls) were screened. By population-based matched case-control design, a normal weight child was randomly selected to match with an obese child by sex, age (difference ≤6 months) and body height (difference ≤5 cm) from the survey area. Conditional logistic regression model was used to analyze association of risk factors with obesity and the interaction of risk factors. Results: ① Univariate conditional logistic regression model showed that 17 risk factors of simple obesity had statistical significance (P<0.001), including high birth weight, cesarean section, gestational diabetes, gestational hypertension, formula feeding in the first 6 months after birth, strong appetite, fast or slow eating speed, low intensity of outdoor activities, daily outdoor activity time <1 hour, daily screen viewing time < 1 hour or ≥2 hours, daily night sleep time <9 hours, mother overweight, father overweight, mother's low educational level, father's low educational level, non-nuclear family structure, and parents not being the primary caregivers of children. ②Multivariate conditional logistic regression model showed that 12 risk factors had statistical significance, including high birth weight (OR=1.83, 95%CI:1.29-2.61, P<0.001), cesarean section (OR=1.22, 95%CI:1.07-1.39, P=0.003), gestational diabetes (OR=4.57, 95%CI:2.13-9.79, P<0.001), mother's low educational level (OR=1.52, 95%CI:1.11-2.07, P=0.008), single parent family (OR=4.79, 95%CI:1.44-15.88, P=0.010), mother overweight (OR=2.58, 95%CI:1.93-3.46, P<0.001), father overweight (OR=2.40, 95%CI:1.86-3.10, P<0.001), strong appetite (OR=7.78, 95%CI:5.38-11.27, P<0.001), fast eating speed (OR=6.59, 95%CI:4.86-8.94, P<0.001), daily outdoor activity time <1 hour (OR=1.42, 95%CI: 1.09-1.85, P=0.009), daily night sleep time <9 hours (OR=1.59, 95%CI: 1.13-2.23, P=0.007), daily screen viewing time ≥2 hours (OR=1.69, 95%CI:1.27-2.24, P<0.001). ③ Interaction of the four groups of risk factors had statistical significance, including interaction between mother overweight and father overweight (OR=5.53, 95%CI: 3.76-8.13, P<0.001), interaction between strong appetite and fast eating speed (OR=54.48, 95%CI: 32.95-90.06, P<0.001), interaction between low intensity of outdoor activity and daily outdoor activity time <1 hour (OR=2.12, 95%CI: 1.29-3.48, P=0.002), interaction between daily night sleep time <9 hours and daily screen viewing time ≥2 hours (OR=2.83, 95%CI: 1.71-4.68, P<0.001). Conclusions: This study identified 12 risk factors of childhood obesity, including high birth weight, cesarean section, gestational diabetes, mother's low educational level, single parent family, mother overweight, father overweight, strong appetite, fast eating speed, daily short outdoor activity time, daily short night sleep time, daily long screen viewing time, and interaction of the four groups of risk factors had statistical significance, including strong interaction between mother overweight and father overweight, interaction between strong appetite and fast eating speed, interaction between low intensity of outdoor activity and daily short outdoor activity time, interaction between daily short night sleep time and daily long screen viewing time.

[Survey on the influential factors of stunting among children under seven years of age in nine cities of China].

Objective: To analyze the influential factors of stunting among children under 7 years of age in nine cities of China in order to provide empirical data for early prevention and intervention for stunting. Methods: The survey was carried out with 1∶1 case-control study design in the communities and kindergartens of nine cities (Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, and Kunming) from June to November in 2016. Children of heights lower than the 3rd percentile according to the 2009 children's height standard in China were included as the stunting case group (n=1 281), and those with normal height matched for geolocation, gender, and age were recruited as the control group (n=1 281). The height and weight were measured on site, and the information related to family, perinatal status, diet and feeding, lifestyle, and medical history was collected by questionnaire. Continuous variables were compared by paired samples t test and Wilcoxon matched-pair signed ranks test, and proportions were compared by paired Chi square test. Multivariate analysis were carried out using conditional Logistic regression model. Results: Among 1 281 pairs of stunting and control group, there were 677 pairs of boys and 604 pairs of girls, with 238 pairs of children under age 3 years and 1 043 pairs of children aged 3 to 7 years. The Z scores for height and weight of stunting group were lower than that of control group (-2.27 (-2.54, -2.08) vs. -0.59 (-1.04, -0.10), -1.85 (-2.35, -1.38) vs. -0.69 (-1.20, -0.21), Z=30.982, 25.580, both P<0.01). Among family related factors, parental education level, height, weight, and height of grandparents in stunting children were all lower than those in control group (all P<0.05). Among individual related factors, proportion of preterm birth, low birth weight, shorter birth length, mother's pregnancy complications, difficulties adding milk or complementary feeding, poor appetite, slow eating, picky and partial eating, passive eating, more snack intake, shorter sleep duration, difficulty falling asleep, disturbed sleep, and recurrent infectious diseases in infant in stunting children were all higher than those in control group (all P<0.05). Multivariate Logistic regression analysis results illustrate that the lower the parental education level and the parental height, the higher the risk of stunting. For example, the risk of stunting in children whose fathers had short stature was 6.46 times (95%CI: 2.73-15.30) of those children whose fathers' height were medium and the risk of stunting in children whose mothers were short stature was 10.56 times (95%CI: 4.92-22.69) of those children whose mothers' height were medium. The risks of stunting increase significantly among preterm children or those with low birth weight (OR=2.27, 95%CI: 1.33-3.88), birth length<45 cm (OR=3.56, 95%CI: 1.41-8.98), difficulties adding milk or complementary feeding (OR=2.04, 95%CI: 1.32-3.15), poor appetite (OR=3.20, 95%CI: 1.74-5.89), slow eating (OR=1.85, 95%CI: 1.31-2.63), and food allergy (OR=1.80, 95%CI: 1.02-3.16). Conclusion: Parental short stature, preterm birth or low birth weight, shorter birth length, feeding difficulty in infant, poor appetite, slow eating, and food allergy are the main risk factors for stunting in infants and children.

[Reference values and growth curves of weight/length, body mass index, and ponderal index of Chinese newborns of different gestational ages].

Objective: To establish the reference values and growth curves of weight/length, body mass index, and ponderal index for Chinese newborns with gestational ages of 24 to 42 weeks, in order to provide a reference for the assessment of body proportionality and nutritional status at birth. Methods: Cross-sectional study design was applied. From June 2015 to November 2018, a total of 24 375 singleton live birth newborns with gestational ages of 24 to 42 weeks from 13 cities including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, Kunming, Tianjin, Shenyang, Changsha, and Shenzhen were selected, excluding those impacting the establishment of the reference values. The generalized additive model for location, scale, and shape (GAMLSS) was employed to establish percentile (P3, P10, P25, P50, P75, P90, P97) reference values and growth curves of weight/length, body mass index, and ponderal index for male and female newborns with gestational ages of 24 to 42 weeks. The established growth standards in this study were compared with the standards from the 1988 Chinese data, the INTERGROWTH project, and the USA reference values. Results: A total of 24 375 newborns with 12 264 preterm newborns (7 042 males and 5 222 females) and 12 111 full-term newborns (6 155 males and 5 956 females) were included in this study. The percentile reference values and growth curves of weight/length, body mass index, and ponderal index were obtained for male and female newborns with gestational ages of 24 to 42 weeks. Weight/length of males in all gestational ages at P10, P50 and P90 was 0 to 0.2 kg/m higher than that of females, and body mass index of males in all gestational ages at the P10, P50 and P90 was 0.1 to 0.3 kg/m2 higher than that of females. The established growth curves of weight/length and body mass index at the upper percentile and ponderal index at both upper and lower percentiles were greatly different from those of the 1988 Chinese data, which, for example, reported the difference ranges at P90 as -1.09 to 0.40 kg/m for weight/length, -1.19 to 0.92 kg/m2 for body mass index, and -0.64 to 0.81 kg/m3 for ponderal index. The established weight/length curves were generally consistent with the reference values from the INTERGROWTH project with a difference of -0.17 to 0.20 kg/m at P50, while being 0.02 to 0.40 kg/m lower at P90 and 0.13 to 0.41 kg/m higher at P10 than that of the INTERGROWTH reference values at gestational ages of ≤32 weeks. The established body mass index curves differed from that of the USA reference values with a difference of -0.47 to 0.17 kg/m2 at P50, while being 0.53 to 1.10 kg/m2 lower at gestational ages of ≥37 weeks but 0.17 to 0.45 kg/m2 higher at gestational ages of ≤28 weeks than that of the USA reference values at P90. Conclusion: The establishment of the new standardized growth reference values of weight/length, body mass index, and ponderal index for Chinese newborns by different gestational ages are useful for clinical practice and scientific research.

[Percentile reference value of waist circumference for Chinese children aged 3-7 years].

Objective: To study and establish the percentile reference values of waist circumference (WC) for Chinese children aged 3-7 years. Methods: A total of 26 480 children aged 3-7 years were collected as part of the National Survey on Physical Growth and Development of Children in nine cities (Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou and Kunming) in China from June to November 2015. Sex- and age-specific smoothed percentile reference values of WC were established using the Lambda Mu Sigma method. The P(75) and P(90) curves of WC for children aged 3-7 years in this study were linked with the published P(75) and P(90) cut-off points for Chinese children and adolescents aged 7-18 years. The P(50) percentile of WC in this study was compared with the corresponding percentiles of several foreign studies. Results: The P(5), P(10), P(15), P(20), P(25), P(50), P(75), P(80), P(85), P(90) and P(95) reference values of WC were obtained for boys and girls aged 3-7 years biannually, at the interval of every six months. Results showed that WC at the P(50) had significantly increased from 47.5 cm at the age of 3 to 54.2 cm at the age of 7 for boys and from 47.0 cm at the age of 3 to 52.2 cm for girls at the age of 7. The corresponding WC percentile values appeared a bit higher in boys than those in girls at the same age, with the differences from 0.4 to 3.6 cm. The differences between measured and fitted WC at each empirical percentile ranged from -0.3 to 0.5 cm for both boys and girls aged 3-7 years. The P(75) and P(90) values of WC for boys and girls aged 3-7 years in this study presented a consistent, continuous tendency on age with the published WC cut-off points (P(75) and P(90)) for Chinese children and adolescent aged 7-18. The increasing trend of WC by age in Chinese children aged 3-7 years was consistent with those of foreign studies, at the middle level for boys and lower middle level for girls. Conclusions: Through this study, we established the WC percentile values for Chinese children aged 3-7 years and achieved the continuity in age with the published WC cut-off points for Chinese children and adolescents aged 7-18. These established WC percentile values can be used as reference for clinical practice, health care and scientific research.

[Analysis of homology and drug sensitivity of vaginal isolates of 10 patients with recurrent vulvovaginal candidiasis in recurrent episodes].

Objective: To detect karyotype homology of vaginal isolates from patients with recurrent vulvovaginal candidiasis (RVVC) in recurrent episodes, and to discuss changes of susceptibility of Candida strains to antifungal drugs with clinical progress. Method: s Ten patients were recruited from Beijing Obstetrics and Gynecology Hospital, Capital Medical University from September 2018 to June 2019, who were firstly diagnosed with RVVC. Vaginal discharges were collected before first treatment and after first relapse. Vaginal strains were isolated, purificated and identificated. Then karyotype of 20 strains isolated from 10 patients were detected by restriction endonuclease analysis of genomic DNA (REAG) using enzyme BssHⅡand pulsed field gel electrophoresis (PFGE) methods, and sensitivity of clinical isolates to 5 antifungal drugs (clostridium, fluconazole, miconazole, itraconazole and nystatin) was also detected using disk diffusion method. Result: s (1) All 20 strains of 10 patients with RVVC were Candida albicans, and their chromosomes were extremely similar after BssHⅡ enzyme digestion. The gene bands of isolated strains from the same patient were completely identical. (2) After clinical medication, the sensitivity of vaginal isolates to azoles was generally decreased, but remained highly sensitive to nystatin, nystatin (first and second clinical isolates: 100% sensitivity and 100% sensitivity)>clotrimazole (100% sensitivity and 90% sensitivity)>fluconazole (80% sensitivity and 70% sensitivity)>itraconazole (60% sensitivity and 50% sensitivity)>miconazole (30% sensitivity and 20% sensitivity). Conclusions: (1) The latency of the same colonized strain in the vagina may be the cause of repeated RVVC episodes. (2) Antifungal agents could selectively induce drug resistance to Candidas, and Candidas show cross-resistance to antifungal agents. Repeated fungal culture and drug sensitivity test in patients with RVVC are very necessary for correct selection of antifungals.

[Survey on the stunting of children under seven years of age in nine cities of China].

Objective: To survey the children under 7 years of age in nine cities of China for a better understanding of the current situation of childhood stunting. Methods: According to a stratified cluster sampling design, a cross-sectional survey on children under 7 years of age was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to November in 2016. A total of 110 499 children were recruited. Height of children was evaluated using the growth standards for Chinese children (2009 edition) .Children with height less than the 3rd percentile of the growth standards were considered as stunting, and children with height between the 3rd and 10th percentiles of the growth standards were considered as relatively short stature. Chi-square test was used for comparison between data of boys and girls, urban and suburban, as well as among different ages and regions. Results: Totally 113 084 children under 7 years of age should be investigated and actually 110 499 children were investigated, with a rate of 97.7%. The prevalence of stunting was 1.9% (2 141/110 499) among all the children. The prevalence of stunting in urban children (1.6%, 904/55 524) was lower than that in suburban children (2.3%, 1 237/54 975, χ(2)=56.246, P<0.01). The gender difference in stunting prevalence was not statistically significant (1.9% (1 121/57 921) in boys and 1.9% (1 020/52 578) in girls, χ(2)=0.003, P=0.965). The prevalence of stunting decreased with age for children younger than 3 years, from 1.8% (312/17 080) in 0-<1 year of age group to 1.2% (168/13 740) in 2-<3 years of age group, but increased to 2.2% (240/11 073) at 6-<7 years group. Comparison among different regions showed that the stunting prevalence in southern region was higher than those in the central and northern regions (0.9% (193/20 374) in northern urban, 0.8% (154/18 486) in central urban, and 3.3% (557/16 664) in southern urban children), showing a statistical significance (χ(2)=437.736, P<0.01); 1.1% (241/21 924) in northern suburban, 1.4% (227/16 775) in central suburban and 4.7% (769/16 276) in southern suburban children, showing a statistical significance (χ(2)=646.533, P<0.01). In urban areas, the difference between the central and northern regions showed no statistical significance (χ(2)=1.429, P=0.232) and the stunting prevalence of central Chinese children was slightly higher than that of northern Chinese children in suburban areas (χ(2)=5.130, P=0.024). Among the nine cities, the stunting prevalence of Guangzhou (6.1%, 613/10 019) was higher than those of other cities (χ(2)=1 559.64, P<0.01). Among the stunting children, 78.4% (1 679/2 141) were classified as borderline or mild and only 7.2% (154/2 141) were classified as severe. The prevalence of relatively short stature was 5.2% (5 721/110 499). Conclusions: The prevalence of stunting among children under 7 years of age in nine cities of China is low and most of the stunting children were classified as mild; the prevalence of stunting in suburban children is higher than that in urban children; the gender difference show no statistical significance; and the prevalence of stunting in southern Chinese children is higher than those in central and northern Chinese children.

[Timing of permanent tooth emergence and its association with physical growth among children aged from four to seven years in nine cities of China].

Objective: To investigate the timing of permanent tooth emergence and its association with physical growth among children aged 4-7 years in 9 cities of China, and to analyze the trend of permanent teeth development. Methods: According to a stratified cluster sampling design, a cross-sectional survey on the timing of permanent tooth emergence children aged 4-7 years was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; Guangzhou, Fuzhou and Kunming in southern China) from June to October in 2015. A total of 37 973 children (19 035 boys and 18 938 girls) were recruited and were divided into different age groups (4.0-<4.5, 4.5-5.0, 5.0-5.5 and 6.0-<7.0 years of age). The situation of the exfoliation of primary teeth and the eruption of permanent teeth were investigated. Height and weight were measured using the standardized methods. Z-scores of physical growth indicators were calculated using the growth standards for Chinese children in 2009. Probit regression analysis was used to determine the median and percentile age of transition from deciduous to permanent teeth. Chi-square test was used for comparison of categorical data and t test was used for comparison of measurement data between boys and girls, urban and suburban as well as among different ages and regions. Meanwhile, the data from the national survey on physical growth and development of children under 7 years of age in 9 cities of China in 1995 were used to analyze the trends of the permanent teeth development. Results: The rate of transition from deciduous to permanent teeth in 37 973 children aged 4-7 years was higher with age, which was 0.6% (42/7 568) in 4.0-<4.5 years of age group, 30.3% (2 295/7 583) in 5.5-<6.0 years of age group, and 74.5% (5 680/7 627) in 6.0-<7.0 years of age group. The rates of transition from deciduous to permanent teeth in boys were all lower than those of girls except for children aged 4.0-<4.5 years (all P<0.01). The rate of transition from deciduous to permanent teeth in urban children was higher than that in suburban children for older than 5.5-6.0 years of age group in boys and older than 4.5-5.0 years of age group in girls, which was 74.2% (1 427/1 924) in urban boys aged 6.0-<7.0 years and 69.2% (1 305/1 885) in suburban boys aged 6.0-<7.0 years (χ(2)=11.446, P<0.01). The age of transition from deciduous to permanent teeth was 6.00 (95%CI: 5.98-6.01) years and the range of the 3-97 percentile was 4.88-7.11 years of age. The median permanent tooth emergence age of girls was lower than that of boys (5.94 vs. 6.06 years) and the median age of urban children was lower than that of suburban children (5.94 vs. 6.05 years). The median permanent tooth emergence age of southern Chinese children (6.05 years) was higher than that of northern (5.97 years) and central Chinese children (5.97 years). The weight for age Z-scores (WAZ), height for age Z-scores (HAZ) and body mass index for age Z-scores (BMIZ) of children with transition from deciduous to permanent teeth (0.35±1.17, 0.32±1.00, 0.23±1.16) were significantly higher than those of children without transition from deciduous to permanent teeth (0.03±1.13, 0.03±1.02, 0.04±1.13, t=20.81,21.67,12.09, all P<0.05). In comparison with the data in 1995, data in 2015 showed that the rate of transition from deciduous to permanent teeth was higher, for example, the rate of urban boys aged 6.0-<7.0 years group was 63.8% (1 146/1 796) in 1995, and increased to 74.2% (1 427/1 924) in 2015 (χ(2)=46.748, P<0.01). The median permanent tooth emergence age decreased by 0.24 years in 2015 as compared with that in 1995. Conclusions: The development of permanent teeth is earlier in girls than in boys, earlier in urban children than in suburban children and slightly delay in southern children than in central and northern Chinese children. In addition, the development of permanent teeth, which is related to the physical growth, slightly accelerate in China during the past 20 years.

[Development of primary teeth among infants and toddlers in nine cities of China in 2015].

Objective: To investigate the status of the development of primary teeth and to identify the development patterns among infants and toddlers in nine cities of China in 2015. Methods: Healthy children aged 1-<36 months were investigated by across-sectional survey and retrospective studies, which was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to October in 2015. Subjects (n=103 995) were divided into 14 age groups (1-<2, 2-<3, 3-<4, 4-<5, 5-<6, 6-<8, 8-<10, 10-<12, 12-<15, 15-<18, 18-<21, 21-<24, 24-<30, 30-<36 months). There were 150-200 boys and girls respectively in each group of urban and suburb areas in each city. The eruption status and the number of primary teeth were examined by the trained child health care physician or pediatrician on the spot. The timing of primary teeth eruption of children was retrospectively surveyed using a questionnaire. The prevalence of primary teeth was calculated and χ(2) test was used for comparison of categorical data. Probit regression analysis was used to determine the median and percentile age of eruption of primary teeth. Results: Totally 103 995 children aged 1-<36 months were investigated. There were 52 346 children in urban areas (boys 26 228, girls 26 118) and 51 649 children in suburb areas (boys 25 912, girls 25 737). The eruption rate of primary teeth in children under 2 years became higher with age and the difference among each age group was statistically significant (χ(2)=85 913.868, P<0.01), which was 0.3% (22/7 450) in 3-<4 months group, 43.0% (3 227/7 503) in 6-<8 months group and 99.9% (7 441/7 446) in 15-<18 months group. The eruption age of primary teeth was 6.6 months (95%CI: 6.5-6.7 months), and the range of the 3rd to 97th percentile was 4.1-10.6 months. The eruption ages of primary teeth in urban and suburb areas children were 6.6 months (95%CI: 6.5-6.7 months) and 6.6 months (95%CI: 6.5-6.7 months) respectively. The eruption age of primary teeth was earlier in boys (6.4 months, 95%CI: 6.3-6.5 months) than that in girls (6.7 months, 95%CI: 6.6-6.8 months). The median eruption age of primary teeth was earlier in northern China (6.2 months) than that in central (6.7 months) and southern China (6.9 months). The eruption rate of primary teeth became higher with age, showing that the median number of primary teeth was 2 in 8-<10 months group, 8 in 12-<15 months group and 20 in 30-<36 months group. Conclusions: The timing of eruption of primary teeth was similar between urban and suburb areas children and that of the boys was slightly earlier than that of the girls. There were slight differences among different regions in the eruption timing of primary teeth. The range of the 3rd to 97th percentile in the eruption age of primary teeth was 4.1-10.6 months and the number of primary teeth followed the regular development pattern with age.

[The preliminary development of reference values of carotid artery intima-media thickness in children aged 6-11 years].

Objective: To develop the reference values of carotid intima-media thickness (cIMT) in Chinese children aged 6-11 years. Methods: A convenient cluster sampling method was used to conduct a cross-sectional survey from November 2017 to January 2018 in a primary school in Huantai County, Zibo City, Shandong Province. A total of 1 033 children aged 6-11 years (excluding children with obesity or hypertension) were included. Percentile curves for cIMT were drawn using the lambda, mu and sigma (LMS) method. Results: This study developed the cIMT reference values (P(90) and P(95)) for sex and age aged 6-11 years, including P(90) and P(95) reference values of mean cIMT, left cIMT and right cIMT, respectively. With the increase of age, the cIMT percentile values also increased. For the same age and the same percentile, the cIMT values of boys were higher than those of girls. Conclusion: This study developed sex-specific and age-specific cIMT percentile reference values in children aged 6-11 years.

[Development and validation of a simplified height-specific blood pressure cutoffs table for screening hypertension in Chinese children and adolescents].

Objective: To develop and validate a simplified height-specific blood pressure cutoffs table for screening hypertension in Chinese children and adolescents. Methods: We developed a simplified height-specific blood pressure cut offs table according to Chinese Blood Pressure Reference for Children and Adolescents aged 7-18 years (WS/T 610-2018) (hereafter referred to as "complex definition"). Populations from Early Warning, Diagnosis and Treatment of Children Cardiovascular Disease Project ("Ji'nan sample") and Shandong Children Cardiovascular Cohort Study Project ("Zibo sample") were used as validation populations for evaluating the screening effect of the simplified table for elevated blood pressure and hypertension in children and adolescents. Results: We developed simplified height-specific blood pressure cutoffs table including 7 height groups and 28 cutoffs. Both Ji'nan and Zibo samples were selected by convenient sampling method, and the former included 7 233 participants aged 7 to 17 years, among whom 3 790 (52.4%) were boys. Latter population included 1 277 participants aged 7 to 11 years, among whom 681 (53.3%) were boys. The simplified table performed well for identifying elevated blood pressure in Ji'nan sample, with values of area under the receiver operating curve (AUC) (95%CI), sensitivity, specificity, and Kappa statistic as 0.96 (0.95-0.97), 93.0%, 98.5% and 0.91, respectively, which were similar with results in Zibo sample [the values were 0.92 (0.90-0.95), 87.0%, 98.0% and 0.85, respectively]. The simplified table also performed well for identifying hypertension in Ji'nan sample with values of AUC (95%CI), sensitivity, specificity, and Kappa statistic as 0.92 (0.91-0.94), 86.9%, 98.1% and 0.85, respectively, which were similar with results in Zibo sample [the values were 0.94 (0.91-0.96), 88.2%, 98.9% and 0.88, respectively]. Conclusion: Screening for elevated and high blood pressure based on simplified height-specific blood pressure cutoffs table is easy to use and it shows satisfying effect.

[Survey on gross motor development of infants in nine cities of China in 2015].

Objective: To analyze the current situation of gross motor development of infants in nine cities of China and their relationship with physical growth. Methods: Healthy full-term infants aged 1-24 months were investigated by cross-sectional survey, which was carried out in nine cities (Beijing, Harbin, Xi'an in northern, Shanghai, Nanjing, Wuhan in central, and Guangzhou, Fuzhou, Kunming in southern regions of China) from June to October in 2015. Subjects were grouped into 12 age groups (1-<2, 2-<3, 3-<4, 4-<5, 5-<6, 6-<8, 8-<10, 10-<12, 12-<15, 15-<18, 18-<21, 21-<24 months). Gross motor development of infants was examined by fieldworkers and the information on parental education, family income and birth status were obtained by questionnaire. Weight, length and head circumference was measured by fieldworkers according to standard methods in the fields and their Z scores were calculated by using WHO growth standard. Z scores of weight (WZ), length (LZ) and head circumference (HCZ) <-2 s was considered as lower group, -2 s-<-1 s as medium-lower group, -1 s-1 s as medium group, 1 s-<2 s as medium-higher group and ≥2 s as higher group. The age of gross motor development was calculated by Probit regression analysis and χ(2) test was used for comparison of categorical data. Results: (1) The number of infants whose gross motor development was examined were 88 968 in the nine cities. The proportion of achievement of motor development became larger with the chronological age, i.e. it was 11.1% (800/7 236) at 5-<6 months, 65.2% (4 921/7 545) at 6-<8 months and 98.5% (7 417/7 531) at 8-<10 months for sitting alone without support. There was no gender difference in the proportion of achievement of sitting alone without support, hand-knee crawl, stand alone and walk alone (χ(2)=2.873, 0.275, 0.250, 0.576, all P>0.05). (2) The median age of achievement of sitting alone without support, hand-knee crawl, stand alone, walk alone was respectively 5.9, 7.8, 10.8, 13.0 months, and their ranges from 1(st) to 99(th) percentile were respectively 4.2-8.3 months, 4.9-12.6 months, 7.6-15.4 months, 9.8-17.4 months. The gender difference of median age of gross motor development was 0.0-0.1 months and their regional difference was 0.0-0.7 months. (3) In the lower weight group, their median age of sitting alone without support and walk alone were 0.2-0.6 months later than the medium weight group, while their median age of hand-knee crawl and stand alone were similar to those of the medium weight group. In higher weight group, the median age of sitting alone without support and stand alone were similar to that of the medium weight group, while their median age of hand-knee crawl was 0.3 later months and their median age of walk alone was 0.3 months earlier than that of the medium weight group. There was no significant relationship between length and the age of sitting alone or standing alone (the difference was 0.0-0.2 months in each group). The median age of hand-knee crawl and walk alone was 0.4-0.7 months later in lower length group than in other length groups. The median age of gross motor development was similar among different head circumference groups (0.0-0.2 months). The relationship between weight/length and motor development was similar to that between weight and motor development. Conclusions: There were no gender difference and slightly regional difference in the age of achievement of gross motor skills. The percentile age of gross motor skills helps to understand the population variation in healthy infants. The gross motor development is related with weight, length and body proportion.

[Development of anterior fontanelle in Chinese children in 2015].

Objective: To observe the development of the anterior fontanel (AF) in healthy Chinese children from 1 to 36 months, and to assess the relationship between the closure of the AF and physical development in Chinese children. Method: This was a cross-sectional evaluation of the AF in a series of 104 147 healthy children between June 2015 and October 2015 from nine cities in China. The size and closure of AF of the children were measured and recorded, and the age for the closure of AF was calculated using probit analysis. The data in 2015 were compared with the data from the same surveys in 1985, 1995 and 2005 respectively. Result: (1) Totally, 104 147 healthy children (52 216 boys and 51 931 girls; range 1 month to 36 months) from nine cities enrolled in this cross-sectional study. (2)The size of AF gradually decreased with age, and the mean size of AF was 2.0(95% confidence interval (CI)2.0-2.1) cm at the age of 1 month, 0.6(95% CI 0.5-0.6) cm at the ages of 12-14 months, and 0.0(95% CI 0.0-0.0) cm at the ages of 21-23 months, respectively. (3) The percentage for the closure of AF was 0.1% at the age of 3 months, 67.5% at the ages of 15-17 months. The oldestt age for closure was 35 months. The mean age for the closure of AF was 14.5 months (95% CI 14.4-14.6), and the 3rd and 97th centiles of the age for the closure of AF were 6.6 and 22.4 months. (4) Over the past 30 years from 1985 to 2015, no significant change was found regarding the mean age for the closure of AF in children from urban area, contrarily, the mean age was 1.1 months earlier in suburban area. (5) The height and weight of children in the closed AF group were significantly higher than those of children in unclosed AF group(all P<0.01), but no significant difference was found regarding the head circumference between the two groups. Conclusion: The size of AF at 1 month was maximum, then decreases gradually with age, and the mean age for the closure of AF was 14.5 (95% CI 14.4-14.6) months. No significant correlation was found between the development of AF and the head circumference, but there was a positive correlation between the development of AF and the height and weight. There was no significant change regarding the secular trend of the age for the closure of AF.