We present a program, SCHNArP, for rebuilding double-helical nucleic acid structures from a set of helical parameters. The parameter sets are based on mathematically reversible schemes that allow direct comparison of data from experimental X-ray crystal structures analyzed using the analysis program, SCHNAaP (see accompanying paper), and structures built using the rebuilding program, SCHNArP. The program uses either local CEHS helical parameters or global helical parameters. A number of standard parameter sets from the literature are included that allow comparison of oligomer and polymer structures generated using different models for sequence-dependent DNA bending. Exact atomic models are provided for the bases. Schematic models that trace the path of the backbone and use rectangular blocks for the bases can be generated.

Background Progesterone is widely used to improve the adverse pregnancy outcomes related to vaginal bleeding during early pregnancy. However, the evidence of its effectiveness is equivocal. Methods Six thousand six hundred fifteen mother-infant pairs from Tongji Maternal and Child Health Cohort (TMCHC) were involved in the study. Information on vaginal bleeding, progesterone administration in early pregnancy were obtained at enrolment. Birth outcomes were obtained from the hospital notes. Body weight of the infants at 12 months of age was collected by telephone interview. Multivariable logistic regression was conducted to estimate the effect of vaginal bleeding and progesterone administration in early pregnancy on birth outcomes and weight status of infants at 12 months of age. Results 21.4% (1418/6615) participants experienced bleeding in early pregnancy, and 47.5% (674/1418) of them were treated with progesterone. There were no significant associations between progesterone supplementation in early pregnancy and offspring outcomes. Compared to women without bleeding or any therapy, women with bleeding and progesterone therapy experienced increased risk of preterm (OR 1.74, 95% CI 1.21–2.52), and delivering a small-for-gestational-age (SGA) (OR 1.46, 95% CI 1.07–1.98) or low birth weight (LBW) (OR 2.10, 95% CI 1.25–3.51) neonate, and offspring of them had an increased risk of weight for age z-score (WAZ) < -1 at 12 months of age (OR 1.79, 95%CI 1.01–3.19). Conclusions Offspring of mothers with bleeding and progesterone therapy were more likely to be a premature, SGA or LBW neonate, and had lower weight at 12 months of age. Progesterone supplementation may have no beneficial effect on improving adverse offspring outcomes related to early vaginal bleeding. Trial registration TMCHC was registered at clinicaltrials.gov as NCT03099837 on 4 April 2017.

AbstractThe high overall plant-based diet index (PDI) is considered to protect against type 2 diabetes in the general population. However, whether the PDI affects gestational diabetes mellitus (GDM) risk among pregnant women is still unclear. We evaluated the association between PDI and GDM risk based on a Chinese large prospective cohort – the Tongji Maternal and Child Health Cohort. Dietary data were collected at 13–28 weeks of pregnancy by a validated semi-quantitative FFQ. The PDI was obtained by assigning plant food groups positive scores while assigning animal food groups reverse scores. GDM was diagnosed by a 75 g 2-h oral glucose tolerance test at 24–28 weeks of gestation. Logistic regression models were fitted to estimate OR of GDM, with associated 95 % CI, comparing women in different PDI quartiles. Among the total 2099 participants, 169 (8·1 %) were diagnosed with GDM. The PDI ranged from 21·0 to 52·0 with a median of 36·0 (interquartile range (IQR) 33·0–39·0). After adjusting for social-demographic characteristics and lifestyle factors etc., the participants with the highest quartile of PDI were associated with 57 % reduced odds of GDM compared with women in the lowest quartile of PDI (adjusted OR 0·43; 95 % CI 0·24, 0·77;Pfor trend= 0·005). An IQR increment in PDI was associated with 29 % decreased odds of GDM (adjusted OR 0·71; 95 % CI 0·56, 0·90). Findings suggest that adopting a plant-based diet during pregnancy could reduce GDM risk among Chinese women, which may be valuable for dietary counselling during pregnancy.

Current results regarding the effect of folic acid (FA) supplement use on gestational hypertension (GH) and preeclampsia are limited and inconsistent. We aimed to investigate whether FA supplement use was associated with GH and preeclampsia. Participants from the Tongji Maternal and Child Health Cohort with information on periconceptional FA supplement use and diagnosis of GH/preeclampsia were included (n=4853). Robust Poisson regression was used to assess the association of FA supplement use and GH and preeclampsia. Among the 4853 participants in this study, 1161 (23.9%) and 161 (3.3%) women were diagnosed with GH and preeclampsia, respectively. The risk ratio of developing GH was higher in women who used ≥800 µg/d FA supplement from prepregnancy through midpregnancy than nonusers (risk ratio, 1.33 [1.08–1.65]). After adjusting for social-demographic, reproductive, lifestyle factors, family history of hypertension, other supplement use, and gestational weight gain, the adverse association remained significant (risk ratio, 1.32 [1.06–1.64]). Restricting the analysis among women with normal weight, without family history of hypertension, and without gestational diabetes mellitus, the positive FA-GH association still existed. We did not find any significant association between FA supplement use and preeclampsia regardless of adjustment. High-dose (≥800 µg/d) FA supplement use from prepregnancy through midpregnancy was associated with increased risk of GH. Attention should be given to avoid the potential risk of GH due to inappropriate FA supplement use in women who are planning or capable of pregnancy.

BACKGROUNDBreastfeeding has many established health benefits to both babies and mothers. There is limited evidence on the association between delayed lactogenesis and breastfeeding practices.OBJECTIVEWe assessed the association between delayed lactogenesis and breastfeeding practices in women initiating breastfeeding.DESIGNWe used data from a prospective cohort study in Wuhan, China, which enrolled pregnant women at 8-16 weeks of gestation and followed up to postpartum. Women were included who had a singleton live birth, initiated breastfeeding, and provided information on infant feeding. Maternal lactogenesis status was assessed by face-to-face interview at day 4 postpartum. Breastfeeding practices (full breastfeeding and/or any breastfeeding) were queried by telephone interview at 3, 6, and 12 mo postpartum. Poisson regression and Cox regression were used to identify the association between delayed lactogenesis and breastfeeding practices.RESULTSDelayed lactogenesis was reported by 17.9% of the 2877 participants. After adjusting for potential confounders, when compared with timely lactogenesis, delayed lactogenesis was significantly associated with higher risk of inability to sustain full breastfeeding at 3 mo postpartum (RR: 1.24, 95% CI: 1.10, 1.39) and 6 mo postpartum (RR: 1.14, 95% CI: 1.04, 1.24). Delayed lactogenesis was also significantly associated with early termination of any breastfeeding (HR: 1.15, 95% CI: 1.01, 1.30) in the adjusted model. In a combined analysis, women with higher gestational weight gain (GWG, ≥16 kg for underweight and normal weight, 15 kg for overweight/obesity) and who subsequently experienced delayed lactogenesis had the highest risk of ending any breastfeeding earlier (adjusted HR: 1.32, 95% CI: 1.11, 1.55) compared with those who gained less GWG and experienced timely lactogenesis.CONCLUSIONSThis study shows that delayed lactogenesis was associated with low rate of full breastfeeding and shorter duration of any breastfeeding. Greater efforts to promote breastfeeding should be targeted towards women with delayed lactogenesis.

目的 探讨孕早期血清肝酶水平与妊娠期糖尿病(GDM)的关联.方法 研究对象来自同济母婴健康队列(TMCHC),通过问卷调查了解孕妇的一般情况,于孕6～18w检测血清碱性磷酸酶(ALP)、γ-谷氨酰转移酶(GGT)、谷丙转氨酶(ALT)和谷草转氨酶(AST)的水平,孕24～28w经口服75g葡萄糖耐量试验(OGTT)诊断GDM.采用Logistic回归模型评估ALP和GGT与GDM发病风险的关联.结果 本研究共纳入2483名孕妇,其中230人(9.3％)被诊断为GDM.ALP和GGT水平与GDM发生风险呈显著正相关,调整相关混杂因素后,与最低分位相比,ALP最高五分位OR值(95％CI)为2.47(1.57,3.88),ALP每增加一个标准差(SD),GDM风险增加35％;GGT最高五分位OR(95％CI)为1.63(1.04,2.56),GGT每增加一个SD,GDM风险增加20％.以ALP和GGT均低于各自最高五分位为参照,ALP和GGT均位于最高五分位者(ALP≥53.0 U/L且GGT≥19.0 U/L)发生GDM的OR值(95％CI)为2.52(1.63,3.90),仅ALP升高者发生GDM的OR值(95％CI)为1.86(1.27,2.74),仅GGT升高者发生GDM的OR值(95％CI)为1.18(0.77,1.80).结论 孕早期ALP或GGT水平升高均增加GDM的发病风险,两者同时升高GDM的发病风险更大.

Whether delayed onset of lactogenesis (delayed OL) was linked to successful breastfeeding is unclear. We aimed to assess the association between delayed OL and breastfeeding practices in Chinese women. Women form the TMCHC (Tongji Maternal and Child Health Cohort) study, who had OL assessment by face-to-face interview at day 4 postpartum and breastfeeding practices collected at 3, 6 and 12 months postpartum, were selected for the study. Poisson regression and Cox regression were used to identify the association between delayed OL and breastfeeding practices. Delayed OL was reported by 17.7% of the 2691 participants. After adjusting for maternal age, ethnicity, education, income, parity, pre-pregnancy BMI, GDM, gestational weight gain, gestational age, delivery mode, birth weight and breastfeeding information at day 1 postpartum, delayed OL was significantly associated with a higher risk of an inability to sustain full breastfeeding at 3 months postpartum (RR:1.31, 95% CI: 1.16, 1.48) and 6 months postpartum (RR:1.17, 95% CI: 1.07, 1.28), when compared with timely OL. Delayed OL was also significantly associated with early termination of any breastfeeding (HR:1.17, 95% CI: 1.01, 1.34) in adjusted model. This study shows that women with delayed OL had a higher risk of suboptimal breastfeeding practices. Comprehensive efforts should be targeted towards women with delayed OL to promote breastfeeding. Funding was received from National Program on Basic Research Project of China (NO.2013FY114200) and the Fundamental Research Funds for the Central Universities (HUST2016YXZD040) for Nianhong Yang.

Background: A growing number of epidemiologic studies have estimated associations between type 2 diabetes mellitus and exposure to metals. However, studies on the associations of internal assessments of metal exposure and gestational diabetes mellitus (GDM) are limited in scope and have inconsistent outcomes. Objectives: This investigation aimed to explore the associations between urinary nickel (Ni), arsenic (As), cadmium (Cd), antimony (Sb), cobalt (Co), or vanadium (V) in early pregnancy and the subsequent risk of GDM in Chinese pregnant women. Methods: The study population included 2090 women with singleton pregnancy from the Tongji Maternal and Child Health Cohort (TMCHC). Urine samples were collected before 20 gestational weeks, and an oral glucose tolerance test (OGTT) was conducted at 24-28 gestational weeks to diagnose GDM. The concentrations of urinary metals were measured using inductively coupled plasma mass spectrometry (ICP-MS) and were corrected for urinary creatinine. The associations between the risk of GDM and urinary metals were assessed using Poisson regression with a robust error variance with generalized estimating equations (GEE) models and Bayesian kernel machine regression (BKMR). Results: A total of 241 participants (11.53%) were diagnosed with GDM. Five metals (Ni, As, Sb, Co, and V) were found significantly and positively associated with GDM based on single-metal models. In multiple-metal models, for each unit increase of ln-transformed urinary Ni or Sb, the risk of GDM increased 18% [relative risk (RR):1.18, 95%confidence interval (CI): 1.00, 1.38 or RR: 1.18, 95%CI: 1.00, 1.39, respectively]. The BKMR analysis revealed a statistically significant and positive joint effect of the six metals on the risk of GDM, when the urinary levels of the six metals were all above the 55th percentile, compared to the median levels. The effect of metal Ni was significant when the concentrations of the other metals were all fixed at their 25th percentile, and metal Sb displayed a significant and positive effect when all the other metals were fixed at 25th, 50th, and 75th percentiles. Conclusions: To the best of our knowledge, this study is the first to demonstrate that increased concentrations of urinary Ni in early pregnancy are associated with an elevated risk of GDM, either evaluated individually or as a metal mixture. All six metals mixed exposure was positively associated with the risk of GDM, while Sb and Ni were demonstrated more important effects than the other four metals in the mixture.

To investigate the effect of routine oral vitamin D supplementation on acute respiratory infection in exclusively breastfed infants. A retrospective analysis from a multi-center population-based prospective cohort study (TMCHC) in Wuhan, China. We retrospectively analyzed the data on ARI and ARI-related hospitalization experience and the vitamin D supplementation history among the exclusively breastfed infants by 6 months of age, from the TMCHC study. We set the first ARI by 6 months of age as the outcome endpoint, and assessed the infants vitamin D supplementation from birth to the outcome endpoint with or without supplementation and supplementation frequencies (≤ 2 days/week, 3–4 days/week, 5–6 days/week, > 6 days/week). Among 983 exclusively breastfed infants, 433 (44%) had an ARI and 55 (6%) experienced ARI-related hospitalization. Infants with vitamin D supplementation experienced a lower cumulative incidence of ARI than those without by 6 months of age (P < 0.001). Vitamin D supplementation was significantly associated with a decreased risk of ARI (OR = 0.19, 95%CI: 0.13-0.30) and ARI-related hospitalization (OR = 0.17, 95%CI: 0.09-0.30) after adjustment for all confounding factors. Additionally, this association represented a dose-response relationship (P for trend < 0.001). Vitamin D supplementation was associated with a reduced risk of ARI and ARI-related hospitalization among exclusively breastfed infants by 6 months of age, suggesting that vitamin D supplementation is a promising strategy for acute respiratory infection prevention at early childhood. This study is supported by National Program on Basic Research Project of China (NO.2013FY114200), the Fundamental Research Funds for the Central Universities (NO. HUST2016YXZD040), and the National Natural Science Foundation of China (NO. 81573149).

Periconceptional folic acid (FA) supplementation is widely recommended for substantial benefits on preventing neural tube defects (1), but concerns regarding the potential side effects on both mothers and their infants have been raised recently (2,3). Higher plasma folate was found to be associated with higher risk of gestational diabetes mellitus (GDM) (4). A Chinese cohort had reported association between FA supplement use in early pregnancy and increased GDM risk (5). However, no details on FA doses and durations had been addressed. To further understand the safe dose and duration of FA supplement use regarding GDM risk, for the first time, we evaluated the impact of FA supplement use on GDM with consideration of both doses and durations. Participants came from the Tongji Maternal and Child Health Cohort (TMCHC), a cohort investigating the role of maternal nutritional, environmental, and lifestyle influences on the outcomes of pregnant women and their offspring. Information on social-demographic status, reproductive factors, lifestyle factors, illnesses, and medical records was collected via questionnaire-based interviews at enrollment (<16 weeks of gestation) and follow-up visits. The study was approved by the ethics committee (Tongji Medical College of Huazhong University of Science and Technology, NO-201302). Among 8,649 women in TMCHC, after excluding those with diabetes/glucose intolerance prepregnancy, multiple pregnancies, and abortions and without reliable FA information (unclear doses/durations or varying doses) and/or oral glucose tolerance test (OGTT), 4,353 women were eligible for final analysis. The incidence of GDM was 8.6%. All participants were instructed to report at enrollment whether they used any FA or other supplements prepregnancy and in early pregnancy, and if so, the brand, dose, timing, and frequency …

BACKGROUND:Antimony (Sb) has been associated with type 2 diabetes in previous studies. However, the role of Sb in the incidence of Gestational diabetes mellitus (GDM) remains unclear. OBJECTIVES:We investigated the association between Sb exposure during early pregnancy and the risk of GDM. METHODS:We performed a prospective study of 2093 pregnant women from the Tongji Maternal and Child Health Cohort (TMCHC). Sb concentrations were measured in urine samples during early pregnancy by ICP-MS. The association between urinary Sb concentration and GDM incidence was assessed using robust Poisson regression model after adjustment for confounders. RESULTS:The 95th percentile value of creatinine-corrected Sb (CC-Sb) concentration in the urine of all pregnant women was 1.33 μg/g. The CC-Sb concentrations were significantly higher in women with GDM than those without GDM (median value: 0.49 μg/g vs. 0.38 μg/g, p = 0.001). After adjustment for potential confounders, for each one natural logarithmic unit increase in Sb concentration, there was 29% [adjusted relative risk (RR) = 1.29; 95% confidence interval (CI): 1.06, 1.57] increase in the risk of GDM. Women in the highest tertile for CC-Sb had a 1.92-fold (95% CI: 1.42, 2.60) higher risk of GDM compared with women in the lowest tertile (p-value for trend <0.001). CONCLUSION:To our knowledge, this is the first research of an association between urinary Sb levels during pregnancy and GDM. Our study suggests that pregnant women with higher Sb exposure levels may have a higher risk of GDM and this association remains consistent even after stratification.