OBJECTIVES: Few studies have investigated the association between the full range of birth weight and the risk of childhood obesity in high-, middle-and low-income countries. The aim of the present study is to assess the association between different levels of birth weight and the risk of obesity among children aged 9-11 years in 12 countries. METHODS: A multinational, cross-sectional study of 5141 children aged 9-11 years was conducted in 12 countries. Height and weight were obtained using standardized methods. Time spent in moderate-to-vigorous physical activity (MVPA), sedentary and sleeping were objectively measured using 24-h, waist-worn accelerometer (Actigraph GT3X+) monitored for 7 days. Birth weight and other factors (regions, parental education, maternal history of gestational diabetes, children age, gender, breast feeding, gestational age, unhealthy diet scores and healthy diet scores) were collected by parental and children's questionnaires. Multilevel modeling was used to account for the nested nature of the data. RESULTS: The overall prevalence of obesity (BMI z-score4+2 s.d.) was 15.4% for boys and 10.0% for girls. There was a positive association between birth weight and BMI z-scores. The multivariable-adjusted odds ratios (ORs) of childhood obesity were significantly higher among children whose birth weights were 3500-3999 g (OR 1.45; 95% confidence interval (CI): 1.10-1.92), and 44000 g (OR 2.08; 95% CI: 1.47-2.93), compared with the reference group (2500-2999 g). The positive association between birth weight and the odds of childhood obesity was seen in girls, whereas a U-shaped association appeared in boys. CONCLUSIONS: High levels of birth weight, defined as birth weight ⩾ 3500 g, were associated with increased odds of obesity among 9-11-year-old children in 12 countries. However, sex differences in the association between birth weight and the risk of obesity need to be considered when planning interventions to reduce childhood obesity.

In pregnant Chinese women, poor sleep quality, and shorter and longer duration of sleep during pregnancy were independently associated with an increased risk of gestational diabetes.

Hypertensive disorders of pregnancy (HDP) as a group of medical complications in pregnancy are believed to be associated with an increased risk of poor fetal growth, but the influence on offspring’s body composition is not clear. The aim of the present study was to evaluate the association between maternal hypertensive disorders of pregnancy and overweight status in the offspring of mothers with gestational diabetes mellitus (GDM). A cross-sectional study among 1263 GDM mother-child pairs was performed in Tianjin, China. General linear models and logistic regression models were used to assess the associations of maternal hypertension in pregnancy with anthropometry and overweight status in the offspring from birth to 1–5 years old. Offspring of GDM mothers who were diagnosed with hypertensive disorders during pregnancy had higher mean values of Z scores for birth weight for gestational age and birth weight for length, and higher mean values of Z scores for weight for age, weight for length/height, and body mass index for age at 1–5 years old than those of GDM mothers with normal blood pressure during pregnancy. Maternal hypertensive disorders of pregnancy were associated with increased risks of large for gestational age (OR 1.74, 95%CI 1.08–2.79) and macrosomia (OR 2.02, 95%CI 1.23–3.31) at birth and childhood overweight/obesity at 1–5 years old age (OR 1.88, 95%CI 1.16–3.04). For offspring of mothers with GDM, maternal hypertension during pregnancy was a risk factor for macrosomia at birth and childhood overweight and obesity, and controlling the maternal hypertension may be more important for preventing large for gestational age babies and childhood obesity.

Aim To evaluate the relationship between maternal thyroid‐stimulating hormone levels during the first trimester and gestational diabetes risk. Methods In Tianjin, China, 7258 women underwent a thyroid‐stimulating hormone screening test within 12 gestational weeks and then had a glucose challenge test at 24–28 weeks of gestational age. The women with a glucose challenge test ≥7.8 mmol/l underwent a 75 g oral glucose tolerance test. Gestational diabetes was diagnosed following International Association of Diabetes and Pregnancy Study Group criteria. Restricted cubic spline analysis was performed to explore full‐range risk associations of thyroid‐stimulating hormone levels with gestational diabetes. Logistic regression was performed to obtain odds ratios and 95% confidence intervals. Results In all, 594 women (8.2%) had gestational diabetes. Among women with thyroid‐stimulating hormone ≤3.2 mIU/l, a positive association between thyroid‐stimulating hormone levels and gestational diabetes risk was found (adjusted OR: 1.13, 95% CI: 1.00–1.27). There was no relationship between thyroid‐stimulating hormone levels and gestational diabetes risk in univariable and multivariable analyses among women with thyroid‐stimulating hormone >3.2 mIU/l. In subgroup analyses, among women with thyroid‐stimulating hormone ≤3.2 mIU/l and BMI ≥25 kg/m2, the adjusted odds ratio for thyroid‐stimulating hormone levels with gestational diabetes was enhanced to 1.25 (95% CI: 1.02–1.53). Conclusions In pregnant Chinese women, thyroid‐stimulating hormone levels even within normal range in the first trimester were positively related to gestational diabetes risk, especially for pre‐pregnancy overweight/obese women.

Previous studies in general people indicated that hypertensive disorders of pregnancy (HDP) increased the risk of subsequent hypertension after delivery. Some studies found that women with gestational diabetes mellitus (GDM) had an increased risk of HDP. However, very few studies have assessed the association between HDP and the risk of postpartum hypertension among GDM women. To evaluate the association between HDP and the risk of postpartum hypertension among GDM women, a retrospective cohort study was conducted in 1261 women with prior GDM at their postpartum 1–5 years using the baseline data from Tianjin Gestational Diabetes Mellitus Prevention Program. Cox regression models were applied to assess the single and joint associations of having a history of HDP, maternal pre-pregnancy Body mass index (BMI) (normal weight, overweight and obesity), and weight change from preconception to post-delivery with the risk of subsequent hypertension among the GDM women. We found that GDM women with a history of HDP, high pre-pregnancy BMI and weight gain more than 7 kg from preconception to post-delivery had an increased risk of postpartum hypertension. Joint effects analysis revealed that the positive association between a history of HDP in the index pregnancy and the risk of postpartum hypertension was consistent in GDM women with different levels of pre-pregnancy BMI or weight gain from preconception to post-delivery. In conclusion, a history of HDP, high pre-pregnancy BMI and weight gain more than 7 kg from preconception to post-delivery increase the risk of subsequent hypertension in postpartum 1–5 years among GDM women.