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Key findings of the work: Maternal frequent intake of a sufficient amount (>3 times per week, or >50 g day−1) of yogurt in late pregnancy may benefit offspring by decreasing the risk of infantile eczema.

Maternal gestational weight gain (GWG) is an important determinant of infant birth weight, and having adequate total GWG has been widely recommended. However, the association of timing of GWG with birth weight remains controversial. We aimed to evaluate this association, especially among women with adequate total GWG. In a prospective cohort study, pregnant women’s weight was routinely measured during pregnancy, and their GWG was calculated for the ten intervals: the first 13, 14–18, 19–23, 24–28, 29–30, 31–32, 33–34, 35–36, 37–38 and 39–40 weeks. Birth weight was measured, and small-for-gestational-age (SGA) and large-for-gestational-age were assessed. Generalized linear and Poisson models were used to evaluate the associations of GWG with birth weight and its outcomes after multivariate adjustment, respectively. Of the 5049 women, increased GWG in the first 30 weeks was associated with increased birth weight for male infants, and increased GWG in the first 28 weeks was associated with increased birth weight for females. Among 1713 women with adequate total GWG, increased GWG percent between 14 and 23 weeks was associated with increased birth weight. Moreover, inadequate GWG between 14 and 23 weeks, compared with the adequate GWG, was associated with an increased risk of SGA (43 (13·7 %) v. 42 (7·2 %); relative risk 1·83, 95 % CI 1·21, 2·76). Timing of GWG may influence infant birth weight differentially, and women with inadequate GWG between 14 and 23 weeks may be at higher risk of delivering SGA infants, despite having adequate total GWG.

To assess the association between vitamin D (VD) supplementation and the risk of lower respiratory tract infection (LRTI) among infants.This is a nested case-control study from an ongoing prospective birth cohort in Wuhan from 2013. Cases were subjects free of neonatal pneumonia but later developed LRTI during infancy, who were matched with five randomly selected controls by infant sex, birth year, and birth season. We included 190 cases and 950 controls in the final analysis. The primary outcome was the first LRTI incident and the exposure was VD supplementation from birth to the index endpoint. The association between VD supplementation and LRTI risk was assessed using the Cox proportional-hazards regression model.Infants taking supplements had a 59% relative reduction in the hazard ratio of LRTI (HR = 0.41; 95% CI 0.26, 0.64) compared to those not supplemented. There was a linear relationship between LRTI risk and VD supplementation within range of 0-603 IU/day: for each 100 IU per day increment in VD supplementation, infants experienced a 21% lower risk of developing LRTI (adjusted HR: 0.79; 95% CI 0.71, 0.89). The linear relationship was stably observed in the sensitivity analyses as well.VD supplementation was associated with the reduced risk of LRTI throughout infancy, and the optimal supplementation dose for infants may be beyond the current recommendation.

Human activities have significantly increased the release of thallium (Tl) to the environment. However, the study of the relationship between maternal Tl exposure during pregnancy and the risk of preterm birth (PTB) is scarce so far. We aimed to investigate the association between Tl exposure in early pregnancy and the risk of PTB. A total of 2104 pregnant women from the Tongji Maternal and Child Health Cohort (TMCHC) in Wuhan, China were enrolled in the analysis. We collected the urine samples in early pregnancy ( 20 weeks) and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect urinary Tl levels. The association between Tl levels and the risk of PTB was evaluated by an unconditional logistic regression. The median and geometric mean values of Tl levels were 0.35 μg/L (0.47 μg/g creatinine) and 0.33 μg/L (0.47 μg/g creatinine), respectively. Compared with the lowest tertile of Tl levels (≤ 0.37 μg/g creatinine), the highest tertile ( 0.57 μg/g creatinine) was associated with an increased risk of PTB with an adjusted odds ratio (OR) of 2.11 (95% confidence interval (CI): 1.08, 4.12). Stratified analyses showed an elevated risk of PTB related to the highest tertile of Tl levels for male newborns. After excluding women with miss covariate information, gestational diabetes mellitus, pregnancy-induced hypertension, reporting fish intake, or exposed to smoke, the association remained stable. Our results suggested that maternal Tl exposure during early pregnancy was positively associated with the risk of PTB, and Tl exposure may have a sex-specific effect on PTB.

Objective To investigate the association of the maternal serum albumin (MAlb) level with fetal growth and fetal growth restriction (FGR) risk in term-born singletons. Design Prospective cohort study. Setting Four hospital maternity units of the Tongji Maternal and Child Health Cohort study initiated from September 2013 to April 2016 at Wuhan City, in central China. Patient(s) A total of 3,065 mother–offspring pairs. Intervention(s) None. Main Outcome Measure(s) Fetal growth was evaluated by birth weight (BW) and birth length. Fetal growth restriction was defined as BW below the 10th percentile. Result(s) All MAlb levels were within the upper limit of normal. After adjustment for liver function parameters, inflammatory indicators, and others, a reverse U-shaped relationship between MAlb and fetal growth was observed. Specifically, BW increased significantly with an increasing MAlb level when the MAlb level was 36.1 g/L (per g/L: β = −15.1; 95% CI, −21.2, −8.9). There was a similar association between MAlb and birth length. Furthermore, the adjusted odd ratios of FGR across increasing tertiles of the MAlb levels were 1.0 (reference), 1.1 (0.7, 1.8), and 1.7 (1.0, 2.6). Conclusion(s) There was a reverse U-shaped association between MAlb and fetal growth. A higher MAlb level was associated with an increased risk of FGR. Clinical Trial Registration Number NCT03099837.

Manganese (Mn) intake has been found to be linked with risk of type 2 diabetes. However, the role of Mn in the development of gestational diabetes mellitus (GDM) remains to be investigated. This prospective study included pregnant women from the Tongji Maternal and Child Health Cohort. A total of 2327 participants with plasma specimens before 20 weeks were included. Among the pregnant women, 9.7% (225/2327) were diagnosed with GDM. After adjustment, pregnant women with the third and highest quartile of plasma Mn levels had 1.31-fold (RR, 2.31 [1.48, 3.61]) and 2.35-fold (RR, 3.35 [2.17, 5.17]) increased risk of GDM compared with those with the lowest quartile. A 1 standard deviation increment of ln-transformed plasma Mn levels (0.53 μg/L) was related to elevated risks of GDM with RRs of 1.28 [1.17, 1.40]. The positive associations between Mn and GDM remained consistent in all the subgroups. The weighted quantile sum index was significantly related to GDM (RR, 1.60 [1.37, 1.86]). The contribution of Mn (58.69%) to the metal mixture index was the highest related to GDM. Higher plasma Mn levels were found to be linked with elevated fasting and 2 h post-load blood glucose. This study revealed relationships of higher plasma Mn levels in early pregnancy and increased risk of GDM, suggesting that though essential, excess Mn in the body might be a potential important risk factor for GDM.

We prospectively evaluated the association between low-carbohydrate-diet (LCD) score during pregnancy and the risk of allergic diseases in infants up to 2 years.Participants were from a prospective mother-offspring cohort study in Wuhan, China. LCD score was calculated according to the percentage of dietary energy intake from carbohydrate, protein, and fat assessed in late pregnancy using validated food frequency questionnaires. Allergic diseases, including immunoglobulin E (IgE)-mediated allergic diseases, allergic contact dermatitis, and food allergy, were recorded at 3, 6, 12, and 24 months postpartum follow-up. Poisson regression models were used to calculate relative risks (RRs) and 95% confidence intervals (CIs).Among 1636 mother-infant pairs included in the present analysis, 230 infants (14.1%) with IgE-mediated allergic diseases, 77 (4.7%) with allergic contact dermatitis, and 488 (29.8%) with food allergy were, respectively, reported. Independent of total energy intake and other potential confounders, both the lowest quintile (RR, 1.77; 95% CI, 1.13-2.77) and the highest quintile (RR, 1.72; 95% CI, 1.22-2.63), were associated with the risk of IgE-mediated allergic diseases compared with the middle quintile. Among high-carbohydrate-diet pregnant women, substituting 5% of energy from either protein or fat for carbohydrate was associated with a lower risk of IgE-mediated allergic diseases. While among low-carbohydrate-diet pregnant women, substituting 5% of energy from carbohydrate, especially high-quality carbohydrate, for fat was associated with a lower risk of IgE-mediated allergic diseases.Maternal low carbohydrate-high protein and fat, and high carbohydrate-low protein and fat diet were both associated with an increased risk of allergic diseases in the infants up to 2 years. This study may provide an intervention strategy for allergy prevention in early childhood.

Objective:To establish optimal gestational weight gain (GWG) in Chinese pregnant women by Chinese-specific BMI categories and compare the new recommendations with the Institute of Medicine (IOM) 2009 guidelines.Design:Multicentre, prospective cohort study. Unconditional logistic regression analysis was used to evaluate the OR, 95 % CI and the predicted probabilities of adverse pregnancy outcomes. The optimal GWG range was defined as the range that did not exceed a 1 % increase from the lowest predicted probability in each pre-pregnancy BMI group.Setting:From nine cities in mainland China.Participants:A total of 3731 women with singleton pregnancy were recruited from April 2013 to December 2014.Results:The optimal GWG (ranges) by Chinese-specific BMI was 15·0 (12·8–17·1), 14·2 (12·1–16·4) and 12·6 (10·4–14·9) kg for underweight, normal weight and overweight pregnant women, respectively. Inappropriate GWG was associated with several adverse pregnancy outcomes. Compared with women gaining weight within our proposed recommendations, women with excessive GWG had higher risk for macrosomia, large for gestational age and caesarean section, whereas those with inadequate GWG had higher risk for low birth weight, small for gestational age and preterm delivery. The comparison between our proposed recommendations and IOM 2009 guidelines showed that our recommendations were comparable with the IOM 2009 guidelines and could well predict the risk of several adverse pregnancy outcomes.Conclusions:Inappropriate GWG was associated with higher risk of several adverse pregnancy outcomes. Optimal GWG recommendations proposed in the present study could be applied to Chinese pregnant women.

Summary Background & aims Emerging evidence has shown the inverse association between dietary polyphenols intake and type 2 diabetes mellitus risk, however, few studies focus on the prospective effects of polyphenols on gestational diabetes mellitus (GDM). Thus, the aim was to evaluate whether higher polyphenols intake and the intake from fruits and vegetables was correlated to a lower risk of GDM. Methods Dietary intake of polyphenols of women with a singleton pregnancy and without any history of diabetes were obtained by a validated food frequency questionnaire from Tongji Maternal and Child Health Cohort study. Oral glucose tolerance tests were conducted at 24–28 weeks to screen for GDM. Logistic regression models were used to evaluate the association between dietary intake of polyphenols, and the results were presented as odds ratios (ORs) with 95% confidence interval (CIs). Generalized linear models were adopted to determine the association of polyphenols intake with blood glucose concentrations, and the results were presented as coefficients (β) with 95% CIs. Results 185 (8.3%) of 2231 pregnant women were diagnosed with GDM. The intake of total polyphenols was 319.9 (217.8–427.0) mg/d, and the intake from fruits and vegetables was 201.6 (115.3–281.8) mg/d and 63.2 (41.1–92.7) mg/d, respectively. Compared with the lowest quartile, the adjusted ORs (95% CIs) of GDM risk for women with the highest quartile of total polyphenols and flavonoids intake was 0.55 (0.30, 0.99), and 0.57 (0.32, 0.99). The adjusted ORs (95% CIs) of GDM risk was 0.55 0.51 (0.30, 0.87) (P for trend = 0.017) for polyphenols from fruits, 0.58 (0.34, 0.99) (P for trend = 0.038) for flavonoids from fruits, and 0.62 (0.38, 1.00) (P for trend = 0.065) for anthocyanidins from fruits comparing the highest versus lowest quartile. In addition, each 100 mg increase of total polyphenols and polyphenols from fruits was associated with 0.054 (0.008, 0.096) (P = 0.021) and 0.061 (0.012, 0.109) (P = 0.015) decrease in 2-h post-load blood glucose. No significant association was found between total polyphenols from vegetables intake and the risk of GDM. Conclusions Higher dietary intake of total polyphenols and flavonoids and the intake from fruits was associated with lower GDM risk. This study was registered at clinicaltrials.gov as NCT03099837.

Purpose: To evaluate the clinical implication of metabolic score for insulin resistance (METS-IR) during early midpregnancy on subsequent risk of gestational diabetes mellitus (GDM) in Chinese women.Methods: A total of 1747 pregnant women without pre-existing diabetes from the Tongji Maternal and Child Health Cohort (TMCHC) were included in this analysis. Blood glucose and lipid profiles (triglyceride [TG], total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C] and low-density lipoprotein cholesterol [LDL-C]) were measured during 15-19 weeks and 75-g 2-h oral glucose tolerance test was conducted during 24-28 weeks to diagnose GDM. METS-IR was calculated by a modified formula which originally as follows: Ln(2×FPG[mg/dl]+TG[mg/dl])×BMI[kg/m2] /Ln(HDL-C[mg/dl]).Results: The median (interquartile range) of age was 28 (26-30) years, and 19.7% of them were underweight and 11.7% were overweight/obese before pregnancy. The overall incidence of GDM was 9.4% and median (interquartile range) of METS-IR was 27.36 (24.57-31.07). The median METS-IR was significantly increased with the increasing pre-pregnancy BMI categories (22.92 vs 27.72 vs 35.55, P＜0.001). Based on quartiles of METS-IR in women with normal pre-pregnancy BMI, participants were classified into 4 groups. Compared with women in the lowest quartile of METS-IR (＜25.52) , the adjusted RRs (95% CIs) of GDM were 2.15 (1.23-3.74), 1.34 (0.72-2.49), and 3.63 (2.22-5.95) for women in quartile 2 (25.52-27.71), quartile 3 (27.72-30.39) and quartile 4 (≥30.40) after adjusting potential confounds. In addition, a significant increase risk of GDM (adjusted RR [95% CI]: 2.55 [1.83-3.55]) was found in women within the highest quartile of METS-IR (≥30.40) compared to the other 3 lower quartiles (＜30.40).Conclusions: Women with METS-IR (≥30.40) during early midpregnancy were more likely to develop GDM, thus the index might be a reliable early indicator for identifying women at high risk of GDM.

Deoxynivalenol (DON) is a ubiquitous trichothecene mycotoxin in food. DON and its modified forms can cross the placental barrier and influence the foetus' health. Limited information is available on exposure of dietary DON intake of pregnant women in China recently. We estimated the exposure of dietary DON intake of pregnant women in a large sample size (n = 2534) from China. The total DON (tDON) and free DON (fDON) biomarkers in urine were detected by liquid chromatography-tandem mass spectrometry. The mean concentration of tDON was 34.8 ng/mg creatinine, and the fDON was 15.9 ng/mg creatinine. The estimated exposure of dietary DON intake was 0.96-1.91 μg/kg bw/day, and the difference in exposure of DON between the first and second trimesters was statistically insignificant. Approximately 26%-60% of individuals exceeded the provisional maximum tolerable daily intake (PMTDI). The age, pre-pregnancy BMI, and the sampling seasons may be the risk factor for the occurrence of exceeding PMTDI. This survey is the first exposure biomarker for DON in a large sample size from pregnant women in China. We found that the dietary DON exposure in pregnant women was relatively high and particular concern should be paid to the DON exposure during pregnancy.

Background Breastfeeding has many established health benefits to both babies and mothers. There is limited evidence on the association between delayed lactogenesis and breastfeeding practices. Objective We assessed the association between delayed lactogenesis and breastfeeding practices in women initiating breastfeeding. Design We 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. Results Delayed 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. Conclusions This 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.

Background The evidence on the relationship between diet diversity in early life and allergic outcomes was few and inconsistent. We sought to determine the association of food diversity in the first year of life with allergic outcomes in the second year. Methods 2251 mother-infant pairs from Tongji Maternal and Child Health Cohort (TMCHC) were involved in the study. Information on complementary foods introduction was obtained by telephone interview at 6- and 12-months postpartum follow-up. Doctor-diagnosed any allergic diseases in the second year were recorded at 2 years postpartum follow-up. Food allergies in infancy were assessed and self-reported by mothers at each postpartum follow-up. Multivariable logistic regression was used to examine the effect of food diversity at 6 and 12 months of age on later allergic diseases and food allergy. Results 135(6.0%) infants reported allergic diseases at between 1 and 2 years of age. Independent of food allergy history of infants and other potential confounders, less food diversity at 6 months of age was associated with increased risk of later allergic diseases (OR 2.17, 95%CI 1.04-4.50 for 0 vs. 3-6 food groups). By 12 months of age, significant inverse associations with later allergic diseases (OR 2.35, 95%CI 1.03-5.32 for 1-5 vs. 8-11 food groups, and OR 1.98, 95%CI 1.16-3.37 for 6-7 vs. 8-11 food groups) and food allergy (OR 2.10, 95%CI 1.29-3.42 for 1-5 vs. 8-11 food groups) were observed. Children with higher food diversity in both periods had the lowest risk of allergic diseases during the second year of life. Conclusions A more diverse diet within the first year of life was associated with reduced risk of allergic diseases at 1-2 years of age. Introducing higher diversity of foods from 6 to 12 months of age might be an effective strategy to improve the allergy outcomes of infants in later life.

The associations among maternal diet, birth weight, and gestational weight gain are still inconclusive. This study aimed to investigate the associations between maternal dietary patterns and birth weight, and further explore whether GWG mediates these associations. A total of 3,334 pregnant women who completed a validated semi-quantitative food frequency questionnaire from the Tongji Maternal and Child Health Cohort were included. Dietary patterns were extracted by using principal component analysis. Regression models and mediation analyses were performed to explore the associations between dietary patterns and birth weight and the effects of GWG on these associations. Five dietary patterns were identified: “Beans-vegetables,” “Fish-meat-eggs,” “Nuts-whole grains,” “Organ-poultry-seafood” and “Rice-wheat-fruits.” Only women following the “Beans-vegetables” pattern had heavier newborns (β = 47.39; 95% CI: 12.25, 82.54). Women following the “Beans-vegetables” pattern had significantly lower GWG (β = −0.7; 95% CI: −1.15, −0.25) and had a 16% lower risk of excessive GWG and 11% higher odd of adequate GWG. The association between the “Beans-vegetables” pattern and birth weight was negatively mediated by GWG. A dietary pattern enriched in beans and vegetables is beneficial for effectively controlling GWG and increasing birth weight. GWG serves.Clinical Trial Registry: This trial was registered at ClinicalTrials.gov (NCT03099837).

OBJECTIVES: To investigate the association between blood vanadium (V) concentrations in early pregnancy and blood lipid profiles and their implications on gestational diabetes mellitus (GDM). METHODS: We performed a prospective study of 2416 pregnant women from the Tongji Maternal and Child Health Cohort (TMCHC). Demographic characteristics and dietary intake were obtained by questionnaire, and an oral glucose tolerance test (OGTT) was conducted at 24–28 gestational weeks to diagnose GDM. V concentrations and lipid levels were determined by analysis of blood samples, which were collected before 20 gestational weeks, with the use of inductively coupled plasma mass spectrometry (ICP-MS) and commercial assay kits. Multiple linear regression and Logistic regression were used in our analysis. RESULTS: The median (inter quartile range) value of V concentrations of all pregnant women was 0.19 (0.24, 0.32) μg/L. After adjusting for demographic and dietary factors, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and total cholesterol (TC) were correlated positively with blood concentrations of V (p for trend = 0.002 for LDL-C, p for trend = 0.006 for TG and p for trend = 0.003 for TC) while there was a significant negative correlation between high-density lipoprotein cholesterol (HDL-C) and V concentrations (p for trend

Objective Fresh fruit intake has been found to be associated with risk of gestational diabetes mellitus (GDM); however, the evidence is limited and the findings are inconsistent. We aimed to assess the association of fresh fruit intake by fruit subgroups based on their glycemic index (GI) and glycemic load (GL) values and GDM incidence in Chinese pregnant women. Methods We included 3300 eligible women from the Tongji Maternal and Child Health Cohort. Dietary intakes were assessed by using a validated semiquantitative food frequency questionnaire. GDM was diagnosed based on the results of a 75-g, 2-h oral glucose tolerance test. In the adjusted logistic regression model, odds ratios and 95% confidence intervals for GDM were computed for the highest compared with lowest quintiles of fruit intake. Results GDM occurred in 378 (11.5%) of 3300 pregnant women. The average fresh fruit consumption was 381.7 g/d. The adjusted odds ratios (95% confidence intervals) for GDM from the lowest to highest quintile of whole fruit consumption were 1.00 (referent), 0.80 (0.56, 1.12), 0.74 (0.52, 1.05), 0.63 (0.44, 0.92), and 0.41 (0.27, 0.62), respectively; Ptrend Conclusions Our findings suggested an inverse association of fresh fruit intake with the risk of GDM in Chinese pregnant women. In women with GDM risk, low GI and GL fresh fruit consumption should be privileged versus those with high GI and GL.

Background Maternal iodine status has been suggested to affect birth outcomes. Few studies have focused on its effects on fetal growth during pregnancy. Objective This study aimed to assess maternal iodine status during early pregnancy and further examine the relation between maternal iodine status and fetal growth. Methods A total of 2087 singleton-pregnant women participating in the Tongji Maternal and Child Health Cohort study were involved. Urinary iodine concentration (UIC) and creatinine concentration were measured in spot urine samples collected in early pregnancy (

Background: Compliance with dietary guidelines among pregnant women can positively influence not only their own health but also the health of their babies. Measuring the compliance requires professional skills in nutrition and dietary counseling. In China, few simple and effective techniques assess dietary quality among pregnant women, especially in rural areas. We aimed to establish a new simple and effective assessment technique, the “Chinese Dietary Guidelines Compliance Index for Pregnant Women (CDGCI-PW)” and assess the association between maternal dietary compliance and risks of pregnancy complications. Methods: The CDGCI-PW consists of 13 main components which were based on the 2016 edition of the Chinese dietary guidelines for pregnant women. Each component was assigned a different score range, and the overall score ranged from 0 to 100 points. The Tongji Maternal and Child Health Cohort study (from September 2013 to May 2016) was a prospective cohort study designed to examine maternal dietary and lifestyle effects on the health of pregnant women and their offspring. The maternal diet during the second trimester was compared with the corresponding recommended intake of the Chinese balanced dietary pagoda for pregnant women to verify their compliance with dietary guidelines. The association between maternal dietary quality and risks of pregnancy complications was estimated by regression analysis. Receiver operating characteristic (ROC) curves were constructed to identify the optimal cut-off values of CDGCI-PW for gestational hypertension and gestational diabetes mellitus (GDM). Results: Among the 2708 pregnant women, 1489 were eventually followed up. The mean CDGCI-PW score was 74.1 (standard deviation (SD) 7.5) in the second trimester. The majority of foods showed the following trend: the higher the CDGCI-PW score, the higher the proportion of pregnant women who reported food intake within the recommended range. Moreover, a higher maternal CDGCI-PW score was significantly associated with lower risks of gestational hypertension [odds ratio (OR) (95% confidence interval [(CI): 0.30 (0.20, 0.37)] and GDM [OR (95% CI): 0.38 (0.31, 0.48)]. The optimal CDGCI-PW cut-off value for gestational hypertension was ≥68.5 (sensitivity 82%, specificity: 61%, area under the ROC curve, AUC = 0.743), and the optimal CDGCI-PW cut-off score for GDM was ≥75.5 (sensitivity 43%, specificity: 81%, area under the ROC curve, AUC = 0.714). Conclusions: The CDGCI-PW is a simple and useful technique that assesses maternal diet quality during pregnancy, while adherence to the CDGCI-PW is associated with a lower risk of gestational hypertension and GDM.

The 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.

Background The association between iron supplementation and gestational diabetes mellitus (GDM) is still inconclusive, and this association has not been extensively studied in relation to plasma ferritin in the early second trimester. Objectives We aimed to prospectively examine the independent and combined associations of plasma ferritin concentrations and iron supplement use with GDM. Methods We studied 2117 women from the Tongji Maternal and Child Health Cohort in Wuhan, China. Plasma ferritin around 16 weeks' gestation was measured by ELISA kits and information on iron supplement use was collected by questionnaires. GDM was diagnosed by a 75-g oral-glucose-tolerance test (OGTT) at 24-28 weeks' gestation. A log-Poisson regression model was used to estimate the RR of GDM associated with plasma ferritin and iron supplementation. Results The median and IQR of plasma ferritin was 52.1 (29.6-89.9) ng/mL, and 863 (40.8%) participants reported use of iron supplements during the second trimester. A total of 219 (10.3%) participants developed GDM. Adjusted RRs (95% CIs) for GDM across increasing quartiles of plasma ferritin were 1.00 (reference), 2.14 (1.37, 3.34), 2.03 (1.30, 3.19), and 2.72 (1.76, 4.21), respectively. After adjustment, supplemental iron ≥60 mg/d during the second trimester was associated with an increased risk of GDM compared with nonusers (RR: 1.37; 95% CI: 1.02, 1.84). Conclusions Both elevated plasma ferritin concentrations in the early second trimester and use of ≥60 mg/d of supplemental iron during pregnancy are independently associated with increased risk of GDM. Further clinical trials with precision nutrition approaches considering both baseline iron status and supplement use are needed to evaluate the benefits and risks of iron supplementation during pregnancy.

Associations between environmental tobacco smoke (ETS) and the risk of adverse birth outcomes may be confounded. We aimed to clarify the associations of ETS before and during pregnancy with the risk of adverse birth outcomes and determine whether the associations were modified by key potential confounders. A total of 7147 non-smoking mothers from the Tongji Maternal and Child Health Cohort (TMCHC) in Wuhan, China, were included in the final analyses. ETS status was self-reported by pregnant women at their first antenatal care visit before 16 gestational weeks. Information on birth outcomes was extracted from delivery records. Poisson regression was used to identify the association between ETS before and during pregnancy and the risk of adverse birth outcomes. Exposures to ETS before and during pregnancy were reported by 645 (9.0%) and 464 (6.5%) mothers, respectively. Compared with no ETS, continued ETS during pregnancy was associated with an increased risk of preterm birth (PTB) (RR: 1.55, 95% CI: 1.07, 2.25) after adjustment for potential confounders. The association remained consistent in medically indicated PTB and late PTB. The risk of PTB associated with continued ETS during pregnancy was significantly increased in mothers more educated (P for interaction < 0.05). However, the increased risk of low birth weight (LBW) or small for gestational age (SGA) births by ETS during pregnancy was not observed. Exposure to ETS during pregnancy was associated with a higher risk of PTB, but not LBW or SGA births in a Chinese birth cohort.

Summary Background Gestational diabetes mellitus (GDM), body mass index (BMI) and gestational weight gain (GWG) are salient predictors of pregnancy-outcomes. However, findings on the association between GDM, BMI, and GWG with fetal growth measures are limited. Objective The aim of this study was to investigate the effect of GDM on fetal growth measures and birth outcomes. Methods All participants came from Tongji Maternal and Child health cohort, in which pregnant women were enrolled before 16 weeks of gestation and had their weights measured regularly during antenatal visits. GDM was diagnosed by oral glucose tolerance test (OGTT) during 24–28 weeks of gestation. Ultrasound measurements of fetal bi-parietal diameters (BPD), head circumferences (HC), abdominal circumferences (AC) and femur length (FL) before birth were collected and neonate outcomes were obtained from the hospital records. Odds ratios were calculated using logistic regression to assess the association of GDM, pre-pregnancy BMI, and GWG with fetal growth measures of ultrasound and birth outcomes, while controlling confounding. Results Of 3253 singleton pregnant women, 293 (9.0%) were diagnosed with GDM, 357 (11.0%) were overweight before pregnancy, and 1995 (61.3%) had excessive GWG. GDM was associated with decreased intrauterine fetal growth measurements including BPD and AC. Maternal pre-pregnancy overweight was associated with increased fetal HC and neonatal birth weight and length, women gained excessive GWG had increased fetal growth measurements of BPD, HC, AC, FL, neonatal birth weight and length. Offspring of GDM women had increased odds of cesarean section 1.31 (1.03, 1.66) and preterm birth 2.02 (1.05, 3.91) in unadjusted models, but these associations disappeared after adjustment. Compared with neonate born to mothers with normal pre-pregnancy weight, those born to underweight mother had higher risk of SGA, and lower risk of cesarean section, LGA and macrosamia, whereas those born to overweight mother had increased risk of cesarean section, LGA and macrosamia. Compared with neonate born to mothers of adequate GWG, neonate of women with excessive GWG had elevated risk of cesarean section, LGA and macrosamia, but lower risk of preterm birth and SGA. Conclusion Pre-pregnancy BMI, GWG and GDM all associated with fetal growth and birth outcomes. The effect of GDM decreased after adjusting pre-pregnancy BMI and GWG. Early screening and management of GDM, preventing excessive GWG could help protect fetuses of GDM mothers from adverse birth outcomes.

We aimed to evaluate the association of the exposure to environmental tobacco smoke (ETS) during pregnancy and infancy with the risk of upper respiratory tract infections (URTI) in infants based on a Chinese birth cohort study. Among 4178 infants who constituted the final study population, 46.8% experienced URTI in their first year of life. The hazard ratios (HR) and 95% confidence intervals (CI) for the risk of URTI were assessed using Cox regression models. Compared with no ETS during pregnancy, continued ETS during pregnancy was independently associated with a higher risk of URTI (HR: 1.36, 95% CI: 1.13, 1.63) after adjustment for potential confounders and also associated with earlier occurrence of URTI (log-rank P = .002). The association remained consistent across the strata defined according to maternal age, number of siblings, sex, and breastfeeding. Exposure to ETS during infancy was associated with URTI only among infants who were breastfed for less than 12 months (P for interaction

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.

Vitamin D deficiency has been reported to be associated with respiratory tract infection (RTI). However, evidence regarding the effects of vitamin D supplementation on susceptibility of infants to RTI is limited. In this prospective birth cohort study, we examined whether vitamin D supplementation reduced RTI risk in 2,244 infants completing the follow‐up from birth to 6 months of age. The outcome endpoint was the first episode of paediatrician‐diagnosed RTI or 6 months of age when no RTI event occurred. Infants receiving vitamin D supplements at a daily dose of 400–600 IU from birth to the outcome endpoint were defined as vitamin D supplementation and divided into four groups according to the average frequency of supplementation: 0, 1–2, 3–4, and 5–7 days/week. We evaluated the relationship between vitamin D supplementation and time to the first episode of RTI with Kaplan–Meier plots. The associations of vitamin D supplementation with infant RTI, lower RTI (LRTI), and RTI‐related hospitalization were assessed using modified Poisson regression. The median time to first RTI episode was 60 days after birth (95% CI [60, 90]) for infants without supplementation and longer than 6 months of age for infants with supplementation (p < .001). We observed inverse trends between supplementation frequency and risk of RTI, LRTI, and RTI‐related hospitalization (p for trend < .001), with the risk ratios in the 5–7 days/week supplementation group of 0.46 (95% CI [0.41, 0.50]), 0.17 (95% CI [0.13, 0.24]), and 0.18 (95% CI [0.12, 0.27]), respectively. These associations were significant and consistent in a subgroup analysis stratified by infant feeding.

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. Keywords: GDM, Urinary metals, Single-metal models, Multiple-metal models, BKMR models

To assess the longitudinal associations between maternal total bile acid (TBA) levels during early mid-pregnancy and the subsequent risk of gestational diabetes mellitus (GDM). In a prospective cohort study, pregnant women who were enrolled prior to gestational week 16 were followed until delivery. TBA levels were tested during weeks 14–18 of gestation. Using logistic regression, we analyzed the associations between quartiles of TBA and GDM based on a 75-g oral glucose tolerance test (OGTT) at 24–28 gestational weeks. The GDM rate was 7.9% (114/1441). The mean TBA level was higher in women with GDM than in those without GDM (2.1 ± 2.0 vs 1.5 ± 1.0 µmol/L, P = 0.000). The highest TBA level quartile (2.1–10.7 µmol/L) had a 1.78-fold (95% CI 1.01, 3.14) increased risk of GDM compared with that of the lowest quartile (0.0–0.8 µmol/L) after adjusting for pre-pregnancy body mass index (BMI), gestational, age at TBA test and other confounders. High TBA levels were involved in the fasting glucose level rather than that at 1 h and 2 h after OGTT in all participants. Pregnant women with higher serum TBA levels during early mid-pregnancy have a higher risk of developing GDM. TBA may be a new risk factor for GDM.

Breastfeeding is of great benefit to infants and their mothers. Caesarean delivery (CD) have increased worldwide in recent years and emerging evidence has implied that CD may influence the initiation and duration of breastfeeding. However, the findings are inconsistent and intricate. The aim of this study is to illuminate the association between the CD and the initiation and duration of breastfeeding in the first 6 months postpartum. A total of 2058 mother–infant pairs were studied in this prospective study. Delivery information was obtained from birth records. Feeding information in the first 6 months postpartum were collected from face-to-face interviews. Logistic regression was used to explore the association between CD and the initiation and duration of breastfeeding. After adjustment for potential confounders, CD was significantly associated with the unsuccessful initiation of breastfeeding [odds ratio (OR): 1.943, 95% confidence interval (CI): 1.050–3.597] and delayed initiation of breastfeeding [OR: 1.450, (95% CI: 1.041–2.019)], when compared with vaginal delivery (VD). More importantly, for mothers who had initiated breastfeeding, CD was associated with significantly higher risks of an inability to sustain full breastfeeding (OR: 1.369, 95% CI: 1.128–1.662), any breastfeeding at 3 months postpartum (OR: 1.715, 95% CI: 1.265–2.325) and any breastfeeding at 6-month postpartum (OR: 1.462, 95% CI: 1.174–1.820). CD is an independent risk factor for the inability to initiate and sustain breastfeeding. It is desirable to reduce the CD rate and provide specific breastfeeding support during early postpartum period to CD mothers.

Objective Information is limited regarding the possible relationship between diet-related inflammation and the risk of gestational diabetes mellitus (GDM). This study investigated the association between the inflammatory potential of the diet, measured by the dietary inflammatory index (DII), and GDM risk in pregnant Chinese women. Methods This study included 2639 eligible women from the Tongji Maternal and Child Health Cohort. Dietary intake was assessed by a validated semiquantitative food frequency questionnaire and was used to calculate the DII score. The DII was then validated using C-reactive protein measurements in a subsample of 133 pregnant women. GDM diagnoses were collected from medical records based on the results of a 75 g oral glucose tolerance test at 24 to 28 wk gestation. Multivariable-adjusted logistic regression models were performed to estimate the odds ratios (ORs) for GDM risk by DII score, modeled continuously and in tertiles. Results Of the 2639 participants, 13.1% were diagnosed with GDM. DII scores ranged from –4.45 to 3.15 and were positively associated with C-reactive protein (adjusted β : 1.28, 95% confidence interval [CI]: 0.16, 2.40; P trend = 0.023) when comparing DII tertile 3 (most pro-inflammatory) to tertile 1 (most anti-inflammatory). A significant and positive association was observed between DII scores and GDM risk (adjusted OR: 1.43; 95% CI: 1.05, 1.95; P trend = 0.022) comparing the highest versus lowest tertiles. The stratified analysis showed that this association was stronger in pregnant women who were overweight or obese before pregnancy (adjusted OR: 2.20; 95% CI: 1.03, 4.69). Conclusions These findings suggest that a higher DII score, corresponding to a more proinflammatory diet, is associated with a higher risk of GDM, particularly in pregnant women who were overweight or obese before pregnancy.

Aims Iron supplementation has been recommended for healthy pregnancy, but concerns have been raised regarding the potential adverse effects. We sought to examine the impact of periconceptional iron supplement use on subsequent gestational diabetes mellitus (GDM) risk. Methods Participants (N = 5101) with information on periconceptional micronutrient supplementation and diagnosis of GDM were involved. Information on iron supplementation and general characteristics were collected at enrollment and follow-up visits. GDM was diagnosed by oral glucose tolerance tests (OGTT) conducted at 24–28 weeks of gestation. Robust Poisson regression model was used to estimate the relative risks (RRs) and 95% confidence intervals (CI) for the effect of iron supplement use on GDM. Results 10.5% of the participants were diagnosed with GDM and the incidence was significantly higher in users with iron >30 mg/d for more than 3 months (Iron >30-L) than in nonusers. Adjusted RRs (95% CI) were 1.53 (1.21, 1.93) in Iron >30-L group, 1.14 (0.80, 1.61) in users with iron >30 mg/d for 30-S) and 1.15 (0.86, 1.54) in users with iron ≤30 mg/d for any duration (Iron ≤30) respectively, compared to nonusers. This link in Iron >30-L group was even stronger (adjusted RR: 1.70, 95% CI: 1.25, 2.31) when restricting the analysis among primiparous and iron-replete participants without family history of diabetes. There were no significant differences in birth outcomes among groups. Conclusions Periconceptional iron supplementation >30 mg/d for long-term was associated with increased GDM risk. The need and safety of prophylactic iron supplement in iron-replete pregnant women should be reconsidered.