Development and validation of a novel food exchange system for Chinese pregnant women.

BACKGROUND: The dietary nutritional status of pregnant women is critical for maintaining the health of both mothers and infants. Food exchange systems have been employed in the nutritional guidance of patients in China, although their application in the dietary guidance of healthy pregnant women is quite limited. This study aimed to develop a novel food exchange system for Chinese pregnant women (NFES-CPW) and evaluate the relative validation of its application. METHODS: NFES-CPW covers approximately 500 types of food from ten categories and has more elaborate food portion sizes. It established a recommendation index for guiding food selection and used energy, water content, and protein as the exchange basis to balance the supply of energy and important nutrients throughout pregnancy. Furthermore, dietitians used the NFES-CPW and traditional food exchange system to generate new recipes based on the sample recipe. There were 40 derived recipes for each of the two food exchange methods. The food consumption, energy, and key nutrients of each recipe were calculated, and the differences between the two food exchange systems were compared using the Wilcoxon rank sum test or the Chi-square test. RESULTS: The results revealed that compared to those derived from traditional food exchange system, the NFES-CPW derived recipes had a better dietary structure, as evidenced by the intakes of whole-grain cereals, beans excluding soybeans, potatoes, fruits, fish, shrimp and shellfish, as well as eggs (P < 0.05), which were more conducive to reaching the recommended range of balanced dietary pagoda. After calculating energy and nutrients, although these two food exchange systems have similar effects on the dietary energy and macronutrient intake of pregnant women, the intake of micronutrients in NFES-CPW derived recipes was significantly higher than that from the traditional food exchange system, which was more conducive to meeting the dietary requirements of pregnant women. The outstanding improvement are primarily vitamin A, vitamin B2, folic acid, vitamin B12, vitamin C, calcium, iron, and iodine (P < 0.05). Moreover, when compared to recipes obtained from the traditional food exchange system, the error ranges of energy and most nutrients were significantly reduced after employing the NFES-CPW. CONCLUSIONS: Therefore, NFES-CPW is an appropriate tool that adheres to Chinese dietary characteristics and can provide suitable dietary guidance to pregnant women.

Investigation of optimal gestational weight gain based on the occurrence of adverse pregnancy outcomes for Chinese women: a prospective cohort study.

OBJECTIVE: To investigate recommendations for appropriate gestational weight gain (GWG) of Chinese females. METHODS: In total of 3,172 eligible women in the first trimester were recruited into the Chinese Pregnant Women Cohort Study (CPWCS) project. Pregnancy complications and outcomes were collated using the hospital medical records system. The method of occurrence of participants with adverse pregnancy outcomes (Occurrence Method) was conducted to calculate the recommended total GWG for each participant's pre-pregnancy BMI. Occurrence Method data were judged against the Institute of Medicine (IOM) and Japanese recommended criteria in terms of the total occurrence of adverse pregnancy outcomes of pregnant women with appropriate weight gain. RESULTS: The most frequent GWG was ≥ 14 kg and < 16 kg (19.4%), followed by ≥ 10 kg and < 12 kg (15.5%) and ≥ 12 kg and < 14 kg (15.2%). The most frequently occurring adverse pregnancy outcomes were cesarean sections for underweight (30.0%), normal weight (40.4%), overweight (53.6%) and obese (53.7%) women. A large for gestational age (LGA) accounted for 18.0% of the overweight and 20.9% of the obesity group. Gestational diabetes mellitus (GDM) occurred in 16.9% of overweight and 23.1% of obese women. The recommended total GWG in a Chinese women population is ≥ 8 and < 12 kg if underweight, ≥ 12 and < 14 kg for normal weight, ≥ 8.0 and < 10.0 kg if overweight, and < 8 kg for women with obesity. CONCLUSIONS: Current Chinese recommendations provide the optimal ranges of GWG to minimize the occurrence of undesirable pregnancy outcomes for each group of pre-pregnancy BMIs in a Chinese population. TRIAL REGISTRATION: Registered with ClinicalTrials ( NCT03403543 ).

Changes in levels of coagulation parameters in different trimesters among Chinese pregnant women.

BACKGROUND: This article is to explore changes in levels of coagulation parameters in different trimesters among healthy pregnant women in China. METHODS: A total of 760 eligible women were enrolled (first-trimester group: n = 183, second-trimester group: n = 183, third-trimester group: n = 263, non-pregnant group: n = 131). Seven parameters including prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), D-dimer (DD), fibrinogen degradation products (FDP), and antithrombin III (ATIII), of all participants were collected. The non-parametric 2.5th-97.5th percentiles reference intervals were calculated for each parameter. RESULTS: The reference intervals for FIB, PT, APTT, TT, FDP, DD, and ATIII at first trimester were 2.11-4.32 g/L, 10.90-13.85 s, 24.60-39.28 s, 12.95-15.88 s, 0.04-2.55 µg/mL, 0.03-1.15 µg/mL, and 75.57%-125.31%, respectively. The reference intervals at second trimester were 2.31-4.77 g/L, 9.70-12.64 s, 24.16-35.43 s, 12.95-15.88 s, 0.15-7.40 µg/mL, 0.08-2.13 µg/mL, and 74.35%-119.28%, respectively. For the third-trimester, the intervals were 2.39-4.96 g/L, 9.20-11.95 s, 23.90-35.51 s, 13.41-18.00 s, 0.55-13.43 µg/mL, 0.15-3.60 µg/mL, and 71.61%-118.29%, respectively. The third-trimester group showed decreased PT, APTT, and ATIII and increased FIB, TT, DD and FDP as compared with the other groups. CONCLUSION: In this study, level changes of coagulation parameters in different trimesters were observed. And the ranges for coagulation parameters were presented, which may provide some reference for clinicians to more accurately monitor the coagulation and fibrinolytic system in pregnant women.

Development and validation of an LC-MS/MS method for quantifying nine antimicrobials in human serum and its application to study the exposure of Chinese pregnant women to antimicrobials.

BACKGROUND: To study the prevalence of the exposure of pregnant women to antimicrobials, a sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine nine antimicrobials, namely sulfadimidine, sulfapyridine, sulfadiazine, sulfathiazole, ofloxacin, ciprofloxacin, norfloxacin, tetracycline, and lincomycin, in human serum. METHODS: The sample preparation procedure included protein precipitation followed by a cleanup step with solid phase extraction (SPE). Separation was carried out using a CORTECS T3 column (100 × 2.1 mm, 2.7 µm) by gradient elution with a runtime of 8.0 min. Detection was performed on a triple quadruple tandem mass spectrometer with scheduled multiple reaction monitoring (sMRM) in positive ion scan mode. RESULTS: The calibration curves were linear over the concentration range of 0.5-50 ng/ml, and the limit of quantitation was between 0.01 and 0.2 ng/ml. For each level of quality control samples, the inter- and intra-assay precision values were less than 12.0%, and the accuracy ranged from 86.1% to 109.0%. No significant matrix effect or carryover was observed. The antimicrobials of interest were stable under all investigated conditions. The validated method was applied to analyze clinical samples from pregnant women in China, and 10 out of 500 samples showed the presence of antimicrobial residues. Moreover, compared with the time-resolved fluoro-immunoassay (TRFIA) method, the developed method showed greater sensitivity and specificity. CONCLUSION: This study provides a simple and rapid LC-MS/MS method for the simultaneous measurement of nine antimicrobials in serum samples, which could be a useful tool in clinical utilization.

Effects of pre-pregnancy body mass index and gestational weight gain on maternal and infant complications.

BACKGROUND: The potential effects of pre-pregnancy body mass (BMI) and gestational weight gain (GWG) on pregnancy outcomes remain unclear. Thus, we investigated socio-demographic characteristics that affect pre-pregnancy BMIs and GWG and the effects of pre-pregnancy BMI and GWG on Chinese maternal and infant complications. METHODS: 3172 women were enrolled in the Chinese Pregnant Women Cohort Study-Peking Union Medical College from July 25, 2017 to July 24, 2018, whose babies were delivered before December 31, 2018. Regression analysis was employed to evaluate the socio-demographic characteristics affecting pre-pregnancy BMI and GWG values and their effects on adverse maternal and infant complications. RESULTS: Multivariate logistic regression analysis revealed that age groups < 20 years (OR: 1.97), 25-30 years (OR: 1.66), 30-35 years (OR: 2.24), 35-40 years (OR: 3.90) and ≥ 40 years (OR: 3.33) as well as elementary school or education below (OR: 3.53), middle school (OR: 1.53), high school (OR: 1.40), and living in the north (OR: 1.37) were risk factors in maintaining a normal pre-pregnancy BMI. An age range of 30-35 years (OR: 0.76), living in the north (OR: 1.32) and race of ethnic minorities (OR: 1.51) were factors affecting GWG. Overweight (OR: 2.01) and inadequate GWG (OR: 1.60) were risk factors for gestational diabetes mellitus (GDM). Overweight (OR: 2.80) and obesity (OR: 5.42) were risk factors for gestational hypertension (GHp). Overweight (OR: 1.92), obesity (OR: 2.48) and excessive GWG (OR: 1.95) were risk factors for macrosomia. Overweight and excessive GWG were risk factors for a large gestational age (LGA) and inadequate GWG was a risk factor for low birth weights. CONCLUSIONS: Overweight and obesity before pregnancy and an excessive GWG are associated with a greater risk of developing GDM, GHp, macrosomia and LGA. The control of body weight before and during the course of pregnancy is recommended to decrease adverse pregnancy outcomes, especially in pregnant women aged < 20 or > 25 years old educated below university and college levels, for ethnic minorities and those women who live in the north of China. TRIAL REGISTRATION: Registered at Clinical Trials ( NCT03403543 ), September 29, 2017.

Preliminary physiologically based pharmacokinetic modeling of renally cleared drugs in Chinese pregnant women.

AIM: The aim of this study was to build and verify a preliminary physiologically based pharmacokinetic (PBPK) model of Chinese pregnant women. The model was used to predict maternal pharmacokinetics (PK) of 6 predominantly renally cleared drugs. METHOD: Based on SimCYP Caucasian pregnancy population dataset, the preliminary Chinese pregnant population was built by updating several key parameters and equations according to physiological parameters of Chinese (or Japanese) pregnant women. Drug-specific parameters of 6 renally cleared drugs were validated through PBPK modeling of Caucasian non-pregnant, Caucasian pregnant and Chinese non-pregnant population. The preliminary PBPK model of Chinese pregnant population was then developed by integrating the preliminary Chinese pregnant population and the drug-specific parameters. This model was verified by comparing the predicted maternal PK of these 6 drugs with the observed in vivo data from the literature. RESULTS: The preliminary Chinese pregnant population PBPK model successfully predicted the PK of 6 target drugs for different pregnancy stages. The predicted plasma concentrations time profiles fitted the observed data well, and most predicted PK parameters were within 2-fold of observed data. CONCLUSIONS: The preliminary Chinese pregnant population PBPK model provided a useful tool to predict the maternal PK of 6 predominantly renally cleared drugs in Chinese pregnant women.

Determinants of exposure levels, metabolism, and health risks of phthalates among pregnant women in Wuhan, China.

Concerns on minimizing health risks of phthalates have been raised due to their widespread exposure and well-documented endocrine disrupting properties, but the determinants of levels, metabolism, and health risks of phthalate exposures have not been thoroughly characterized among the Chinese population, particularly pregnant women. The metabolites of five phthalates were analyzed: diethyl (DEP), diisobutyl (DiBP), di-n-butyl (DnBP), di-(2-ethylhexyl) (DEHP), and benzyl butyl phthalate (BBzP) were analyzed in urine samples collected from 946 mothers in Wuhan during 2014-2015. We applied linear mixed models to investigate the relationships between biomarkers (e.g., urinary concentrations of phthalate metabolites, phthalates, and ratios of metabolites) and factors including sampling seasons and epidemiological characteristics. We calculated estimated daily intake (EDI) using average phthalate concentrations over three trimesters and hazard index (HI) by dividing EDI by tolerance daily intake. About 24.9% of participants were at health risks with HI > 1. The largest health risks were driven by one specific phthalate (DnBP or DEHP). We observed lower urinary levels of phthalate metabolites in winter. Elevated levels were found in mothers with higher education levels or those employed. Mothers who got pregnant on purpose had lower phthalate concentrations than those got pregnant by accident. More recent exposure to phthalates was observed among groups of mothers giving birth to girls, or those who got excessive gestational weight gain. Younger mothers were more susceptible to phthalate exposure. This repeated measurement study suggests that the intervention should be taken to limit application and production of DnBP and DEHP, and highlights that typical demographic factors should be taken into account in demographic studies.

Continuous support during labour in childbirth: a Cross-Sectional study in a university teaching hospital in Shanghai, China.

BACKGROUND: Fear or anxiety could result in adverse consequences on the course of labour. To date, family members are still not permitted in the delivery rooms in the majority of hospitals in China, and continuous support from hospital professional staff is also limited. This study aimed to evaluate the benefits of continuous support by family members and hospital professional staff during labour in China. METHODS: In this Cross-Sectional study, 362 primiparous pregnancies who self-requested to receive continuous or one to one support with vaginal delivery and 362 primiparous pregnant women with routine hospital maternal care were included from a university teaching hospital. Data on the length of labour, postpartum haemorrhage (PPH), use of pain relief, use of oxytocin, fetal distress, emergency caesarean section and apgar score at 1 and 5 min were retrospectively collected from hospital medical data-base and compared between the two groups. RESULTS: Multiple linear regressions adjusting for maternal age, BMI and birth weight, revealed the estimated length of labour for women with routine hospital maternal care was 2.03 times (95%CI 1.86 to 2.21) the duration of women with supportive care (median time, 3.05 h vs 1.5 h). In addition, Fisher's exact test showed the emergency caesarean section rate was significantly lower in women with supportive care compared to women with routine hospital maternal care (3.3% vs 24%). CONCLUSION: Our results suggest that continuous support from family members together with hospital professional staff should be considered as part of intrapartum care in hospitals in China.

Accuracy of sonographic fetal weight estimation prior to delivery in a Chinese han population.

OBJECTIVE: To compare the sonographic-estimated fetal weights (EFW) calculated with the Hadlock formula and with the Woo formula in a group of Chinese pregnant women. METHODS: We prospectively recruited term pregnancies for sonographic biometric examination. EFWs were calculated according to two formulas and compared with the corresponding birth weight (BW). We also assessed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of EFW for the diagnosis of small-for-gestational age (SGA) and large-for-gestational age (LGA) neonates. RESULTS: A total of 374 subjects who delivered within 7 days after the sonographic examinations was recruited. Using the Hadlock formula, the median absolute difference between EFW and BW was 182 g (15-308 g) and the median percentage difference was 5.3% (0.5-9.1%), whereas it was 230 g (62-367) and 7.1% (2.1-10.4%) for the Woo formula (p < 0.001). Several factors, namely the fetal presentation, gender, and high amniotic quantity, showed no evident impact on this predictive difference. Among the 175 women who delivered within 2 days after ultrasound, the sensitivity and specificity of Hadlock EFW were 100% and 97.1% for the detection of SGA and 48.1% and 97.3% for the detection of LGA, respectively. The PPV and NPV were 44.4% and 100.0% for the detection of SGA and 76.5% and 91.1% for the detection of LGA, respectively. CONCLUSIONS: EFWs calculated using the Hadlock formula for our research subjects were as accurate as those reported for other populations. The predictive performance showed a high NPV for the diagnosis of SGA and a relatively acceptable PPV for the diagnosis of LGA. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:465-471, 2017.

Maternal Weight Gain in Early Pregnancy with Healthy Live Offspring: Based on the China Birth Cohort Study.

BACKGROUND: Research on maternal weight gain in early pregnancy with healthy live offspring is lacking for Chinese women. Based on the China birth cohort study (CBCS), we aimed to explore maternal weight gain in different groups. METHODS: Singleton pregnancies of 6 + 0~13 + 6 weeks of gestation from the CBCS were considered, not including missing data or outliers, those lost at follow-up, or those with non-typical conditions of the offspring. Maternal first-trimester weight and body mass index (BMI) gain was considered as the early pregnancy weight minus the pre-pregnancy weight. Using Pearson's or Spearman's correlation and linear regression models to explore the relationship between maternal weight and BMI gain and gestational age (GA), stratified and sensitivity analyses were carried out to identify the study's robustness. RESULTS: There were 25,292 singleton pregnancies with healthy live offspring who were ultimately enrolled, and there was a linear correlation between GA and maternal weight gain (=0.55 + 0.05 × GA (weeks), p < 0.001, r2 = 0.002) and BMI change (=0.21 + 0.02 × GA (weeks), p < 0.001, r2 = 0.002). The association remained robust in the stratified and sensitivity analyses of the subgroups. CONCLUSIONS: Although the association between GA and maternal pre-pregnancy weight and BMI gain is weak, a slight correlation was shown, especially in pregnant women with a typical or low pre-pregnancy BMI, Han ethnicity, moderate levels of physical activity, natural conception, and folic acid (FA) and/or multivitamin supplementation.

Association between Dietary Inflammatory Index and Bone Mineral Density Changes among Pregnant Women: A Prospective Study in China.

OBJECTIVES: This study aims to examine the relationship between dietary inflammatory index (DII) and bone mineral density (BMD) changes among Chinese pregnant women, offering valuable insights for dietary guidance during pregnancy. METHODS: 289 pregnant women were enrolled in this cohort. Serum inflammatory factors and ultrasonic BMD were measured at the first, second, and the third trimesters. DII scores were calculated based on a semi-quantitative food frequency questionnaire (FFQ) and divided into tertiles. We compared the differences in inflammatory factors in serum across the tertiles of DII and changes in BMD at the second and third trimesters across the tertiles. RESULTS: The participants with higher DII scores had higher total energy intakes than those with lower DII scores. The serum level of interleukin-6 (IL-6) was significantly different across the tertiles of the DII. Women who had lower DII scores had higher T-scores and Z-scores in the BMD assessment. In the test of trends, after adjusting potential covariates, including educational level, physical activity, body mass index, and calcium, vitamin D, or multivitamin supplements, DII values were determined to be positively related to the maternal BMD lost. CONCLUSIONS: DII was positively associated with serum IL-6. Meanwhile, higher DII scores were associated with more bone mass loss in pregnant women. We recommend adhering to a lower-DII diet to preserve BMD during pregnancy.

Self-objectification in Chinese pregnant women: The mixed role of functionality appreciation.

Extensions of objectification theory to pregnant women are few and continued research is needed to better understand the psychological consequences of significant changes to physical appearance during pregnancy. Specific interests in this area include functionality appreciation which may be particularly relevant to pregnancy. Research in this area is also lacking representation of non-Western cultural contexts. To this end, we employed an online survey to assess objectification theory and functionality appreciation in Chinese pregnant women (N = 345). Correlations showed that higher body surveillance and body shame were associated with higher disordered eating and psychological distress, and higher functionality appreciation was associated with lower body surveillance, body shame, and disordered eating. Mediation analyses suggested that higher body surveillance was associated with higher body shame which, in turn, was associated with higher disordered eating and psychological distress. Main effects suggested a negative association between functionality appreciation and body shame, but moderation analyses suggested that higher functionality appreciation strengthened the positive association between body surveillance and body shame. Findings underscore objectification theory as a useful framework to understand eating and body image disturbances and psychological distress in Chinese pregnant women and outline future directions to clarify the temporal nature of these associations and the precise role of functionality appreciation.

Incidence of maternal venous thromboembolism in China: A systematic review and meta-analysis.

BACKGROUND: Venous thromboembolism (VTE) is one of the primary causes of maternal death. Although many studies have reported maternal VTE, no study has estimated the incidence of it in China. OBJECTIVES: The aim of this work was to estimate the incidence of maternal VTE in China and to compare the risk factors for it. SEARCH STRATEGY: The authors searched eight platforms and databases including PubMed, Embase, and Cochrane Library from inception to April 2022, with the search terms "venous thromboembolism" AND "puerperium (pregnancy)" AND "incidence" AND "China." SELECTION CRITERIA: Studies provide data to calculate the incidence of maternal VTE among Chinese patients. DATA COLLECTION AND ANALYSIS: The authors made a standardized table to collect data and calculated the incidence and 95% confidence intervals (CIs), founding source of heterogeneity by subgroup analysis and meta-regression and judging publication bias by funnel plot and Egger test. MAIN RESULTS: The included 53 papers with a total sample size of 3 813 871 patients had 2539 cases of VTE, and the incidence of maternal VTE in China was 0.13% (95% CI, 0.11-0.16; P < 0.001). CONCLUSIONS: The trend in the incidence of maternal VTE in China is stable. Cesarean section and advanced age are associated with a higher incidence of VTE.

Association between Prepregnancy Weight Change and Risk of Gestational Diabetes Mellitus in Chinese Pregnant Women.

BACKGROUND: Evidence regarding prepregnancy weight change and gestational diabetes mellitus (GDM) is lacking among East Asian women. OBJECTIVES: Our study aimed to investigate the association between weight change from age 18 y to pregnancy and GDM in Chinese pregnant women. METHODS: Our analyses included 6972 pregnant women from the Tongji-Shuangliu Birth Cohort. Body weights were recalled for age 18 y and the time point immediately before pregnancy, whereas height was measured during early pregnancy. Prepregnancy weight change was calculated as the difference between weight immediately before pregnancy and weight at age 18 y. GDM outcomes were ascertained by 75-g oral-glucose-tolerance test. Multivariable logistic regression models were used to examine the association between prepregnancy weight change and risk of GDM. RESULTS: In total, 501 (7.2%) developed GDM in the cohort. After multivariable adjustments, prepregnancy weight change was linearly associated with a higher risk of GDM (P < 0.001). Compared with participants with stable weight (weight change within 5.0 kg) before pregnancy, multivariable-adjusted odds ratios and 95% confidence intervals were 1.55 (1.22, 1.98) and 2.24 (1.78, 2.83) for participants with moderate (5-9.9 kg) and high (≥10 kg) weight gain, respectively. In addition, overweight/obesity immediately before pregnancy mediated 17.6% and 31.7% of the associations of moderate and high-weight gain with GDM risk, whereas weekly weight gain during pregnancy mediated 21.1% and 22.7% of the associations. CONCLUSIONS: Weight gain from age 18 y to pregnancy was significantly associated with a higher risk of GDM. Maintaining weight stability, especially prevention of excessive weight gain from early adulthood to pregnancy, could be a potential strategy to reduce GDM risk.

Evaluating the accuracy of sonographic fetal weight estimations using the Hadlock IV formula in a Chinese population.

Background: Despite being the most generalized formula in China, the Hadlock IV formula has never been examined to determine if it is suitable for Chinese newborns, nor have the factors that might affect its performance been investigated. However, previous studies have reported varying results about other formulas in other nationalities. This study sought to evaluate the performance of the Hadlock IV formula in estimating fetal weight (FW) in pregnant Chinese women and use ultrasound to identify the factors affecting the accuracy of estimations of newborn weight; through these means, we aimed to create a reference for predicting neonatal weight for obstetricians. Methods: A retrospective observational study comprising data from 976 cases of live-birth singleton pregnancies at the Shanghai General Hospital was conducted. The participants' clinical data were examined and subjected to a logistic regression analysis to identify the multitude of possible factors affecting the estimation of FW. The proportions and correlations between the accurate and inaccurate estimation groups were compared to determine the different prognosis of these 2 groups. The correlations between the accuracy of the sonographic-based fetal weight estimation (SFWE) and newborns with different weight ranges were also analyzed. Results: The overall accuracy rate of the SFWE predicted by the Hadlock IV formula was 79.61%, while that of the inaccurate estimation group was only 20.39%. The incidence of spontaneous vaginal delivery (VD) was lower in the inaccurate estimation group than in the accurate estimation group (40.7% vs. 48.13%; P=0.041). In the inaccurate estimation group, 11.56% (23/199) of the participants underwent a secondary cesarean section (sCS), compared to only 6.44% (50/777) in the accurate estimation group. The low birth weight (LBW) rates and macrosomia rates were lower in the accurate estimation group than in the inaccurate estimation group, with odds ratios (ORs) of 0.483 and 0.459, respectively (P<0.05). The results indicated that the SFWE was more accurate for newborns weighing 2,500-4,000 g than those weight out of this range. In relation to macrosomia, the SFWE was likely to be underestimated, but it was usually overestimated in the LBW group. Conclusions: The overall performance of the Hadlock IV formula in predicting the birth weight of Chinese newborns remains suboptimal. Extra caution should be exercised in cases of suspected large-for-gestational age (LGA) infants, small-for-gestational age (SGA) infants, infants with macrosomia, or LBW fetuses in the Chinese population.

Estimation of the bio-accessibility of methylmercury from aquatic foods using a PBTK model with an approximate Bayesian computation method in Chinese pregnant women.

BACKGROUND: Fish are the primary source of protein and docosahexaenoic acid (DHA) for pregnant women and children, but methylmercury (MeHg) pollution is the potential hazard of fish consumption. In risk assessments, the bio-accessibility of MeHg is usually assumed to be 100%, which could lead to overestimation of dietary exposure. METHOD: An existing PBTK model was adapted to estimate parameters of the bio-accessibility based on MeHg exposure data from a cohort of 397 Chinese pregnant women. The posterior distributions of parameters were determined by using the ABC - MCMC. RMSEP and Spearman's rank correlation coefficients (Rho) were calculated to determine the goodness of model fitting. The Monte Carlo analysis was performed for the parameter distributions to estimate the model variability. RESULT: The median of daily MeHg intake and maternal MeHg levels were 0.018 µg/kg bw and 3.01 µg/kg in the early and middle terms of pregnancy. The estimated bio-accessibility of freshwater fish, marine fish and others were 46.1, 17.3 and 58.2%, separately. The RMSEP improved from 11.18 to 2.54 and the Rho improved from 0.19 to 0.22 after bio-accessibility optimization. The model variability was estimated to be 2.6. CONCLUSION: The bio-accessibility estimated in this study was comparable to that determined in previous in vitro studies. The optimized model could improve the prediction performance on the MeHg body burden by dietary exposure.

Maternal choices and preferences for screening strategies of gestational diabetes mellitus: A exploratory study using discrete choice experiment.

Aims: This study aimed to investigate maternal preferences for gestational diabetes mellitus (GDM) screening options in rural China to identify an optimal GDM screening strategy. Methods: Pregnant women at 24-28 gestational weeks were recruited from Shandong province, China. A discrete choice experiment (DCE) was conducted to elicit pregnant women's preferences for GDM screening strategy defined by five attributes: number of blood draws, out-of-pocket costs, screening waiting-time, number of hospital visits, and positive diagnosis rate. A mixed logistic model was employed to quantify maternal preferences, and to estimate the relative importance of included attributes in determining pregnant women's preferences for two routinely applied screening strategies ("one-step": 75 g oral glucose tolerance test [OGTT] and "two-step": 50 g glucose challenge-test plus 75 g OGTT). Preference heterogeneity was also investigated. Results: N = 287 participants completed the DCE survey. All five predefined attributes were associated with pregnant women's preferences. Diagnostic rate was the most influential attribute (17.5 vs. 8.0%, OR: 2.89; 95%CI: 2.10 to 3.96). When changes of the attributes of "two-step" to "one-step" strategies, women's uptake probability from full "two-step" to "one-step" significantly increased with 71.3% (95%CI: 52.2 to 90.1%), but no significant difference with the first step of "two-step" (-31.0%, 95%CI: -70.2 to 8.1%). Conclusion: Chinese pregnant women preferred the "one-step" screening strategy to the full "two-step" strategy, but were indifferent between "one-step" and the first step of "two-step" strategies.

Variation of the Vaginal Microbiome During and After Pregnancy in Chinese Women.

A comprehensive profiling of the vaginal microbial communities and their variability enables an accurate description of the microbiome in women. However, there is a lack of studies available on Chinese women. In the present study, the composition of the vaginal microbiota during pregnancy and the 6-week postpartum period of 454 Chinese women was characterized by sequencing the V3-V4 region of the 16S ribosomal RNA (rRNA) gene. The vaginal microbiome showed variations during pregnancy and the postpartum period based on the abortion history, hypertensive disorders, delivery mode, and maternal age. Co-variation of 22 bacterial taxa, including the Lactobacillus genus and two of its species, may account for the common characteristics of the vaginal microbiome under scenarios of different medical histories and pregnancy outcomes. In contrast, discriminant bacterial species were significantly different between women who had preterm birth (PTB) with and without premature rupture of membranes (PROM), and the community state type (CST) IV-A without any predominant Lactobacillus species in the microbiota was more prevalent during pregnancy in the PROM-PTB cases, suggesting that specific bacterial species could be considered to distinguish between different types of PTB. By providing data on Chinese women, this study will enrich the knowledge of the human microbiome and contribute to a better understanding of the association between the vaginal microbiome and reproductive health.

Vitamin D Nutritional Status of Chinese Pregnant Women, Comparing the Chinese National Nutrition Surveillance (CNHS) 2015-2017 with CNHS 2010-2012.

Optimal vitamin D (vitD) status is beneficial for both pregnant women and their newborns. The aim of this study was to evaluate the vitamin D status of Chinese pregnant women in the latest China Nutrition and Health Surveillance (CNHS) 2015-2017, analyze the risk factors of vitamin D deficiency (VDD), and compare them with those in CNHS 2010-2012. Serum 25 hydroxyvitamin D (25(OH)D) was measured by ELISA method. City type, district, latitude, location, age, vitamin D supplements intake, education, marital status, annual family income, etc., were recorded. The median 25(OH)D concentration was 13.02 (10.17-17.01) ng/mL in 2015-2017, and 15.48 (11.89-20.09) ng/mL in 2010-2012. The vitamin D sufficient rate was only 12.57% in 2015-2017, comparing to 25.17% in 2010-2012. The risk factors of vitamin D inadequacy (25(OH)D < 20 ng/mL) in 2015-2017 were not exactly consistent with that in 2010-2012. The risk factors included season of spring (p < 0.0001) and winter (p < 0.001), subtropical (p < 0.001), median (p < 0.0001) and warm temperate zones (p < 0.0001), the western (p = 0.027) and the central areas (p = 0.041), while vitD supplements intake (p = 0.021) was a protective factor in pregnant women. In conclusion, vitD inadequacy is very common among Chinese pregnant women. We encourage pregnant women to take more effective sunlight and proper vitD supplements, especially for those from the subtropical, warm and medium temperate zones, the western and the central, and in the seasons of spring and winter.

Evaluation of a Novel WeChat Applet for Image-Based Dietary Assessment among Pregnant Women in China.

As an important part of antenatal care for pregnant women in China, dietary assessment plays a positive role in maternal and fetal health. Shortcomings in the associated methodologies require improvement. Our purpose was to develop a novel WeChat Applet for image-based dietary assessment (WAIDA) and evaluate its relative validity among pregnant women in China. Data on 251 lunch meals of pregnant women in their second trimester were analyzed. The differences in food weight, energy, and nutrient estimates by the dietary recall or WAIDA method with the weighing method were compared using paired t-tests. Pearson correlation coefficients were used to analyze the correlation between food weight, energy, and nutrient intake obtained from the recall or WAIDA method and those obtained from the weighing method. The Bland-Altman analysis was used to examine the agreement between the recall or WAIDA method and the weighing method for energy and nutrients. Compared with the weighing method, the variation range of food weight, energy and nutrients estimated by the WAIDA method was smaller and more stable than that estimated by the recall method. Compared with the recall method, the correlations suggested a better relationship between the energy and nutrient intakes from the weighing method and those estimated by the WAIDA method (0.752-0.970 vs. 0.480-0.887), which were similar to those of food weight (0.332-0.973 vs. -0.019-0.794). The Bland-Altman analysis showed that the mean differences of the energy and nutrients estimated from the recall method were further away from zero relative to the weighing method compared to the WAIDA method and with numerically wider 95% confidence intervals. The spans between the upper and lower 95% limit of agreement (LOAs) of the energy and nutrients obtained by the WAIDA method were narrower than those obtained by the recall method, and the majority of the data points obtained by the WAIDA method lay between the LOAs, closer to the middle horizontal line. Compared with the recall method, the WAIDA method is consistent with the weighing method, close to the real value of dietary data, and expected to be suitable for dietary assessment in antenatal care.