The intention to undertake physical activity in pregnant women using the theory of planned behaviour.

AIM: To identify the intention of Chinese pregnant women to undertake physical activity (PA) using the theory of planned behaviour. DESIGN: A cross-sectional survey. METHODS: From April - October 2017, a cross-sectional questionnaire was completed by 746 pregnant women from the Health Birth Cohort in Wuhan, China. The theory of planned behaviour variables as well as sociodemographic characteristics was recorded, and the Pregnancy PA Questionnaire was together used to assess their PA during pregnancy. RESULTS: Only 11.3% of the women met the international guideline. The intention to undertake PA was found it to be positive in 63.9% of pregnant women. Structural equation modelling analysis revealed that behavioural attitudes, subjective norms, and perceived behavioural control (PBC) influenced PA by directly influencing the behaviour intention. Both behavioural attitude and subjective norms influenced PA by indirectly affecting the behaviour. Overall, the model described 60% variance of the behavioural intention to undertake PA during pregnancy. CONCLUSION: PBC was confirmed to be a prominent factor in determining behavioural intention to undertake PA during pregnancy. Pregnant women should be helped and appropriately guided by health providers to overcome barriers to PA. EFFECT: This study investigates the effect of perceived behavioural control (PBC) on the intention to undertake physical activity (PA). The findings suggest that nurses' and midwives' attention should be focused on how to promote the improvement of perceived behavioural control ability of pregnant women to improve pregnant women's PA intention. The attitude of pregnant women on taking up PA and their ability to control behaviours can be improved with support from family or healthcare providers.

The relationship between urinary selenium levels and risk of gestational diabetes mellitus: A nested case-control study.

Background: Selenium (Se) is an essential trace element for the human body. Serum Se and urinary Se are also biomarkers to assess Se exposure status. However, studies focusing on the association between urinary Se and the risk of gestational diabetes mellitus (GDM) are rare. Objective: To investigate the association between urinary Se and the risk of GDM. Methods: A nested case-control study based on a prospective birth cohort in Wuhan, China, which focuses on the effects of prenatal environmental factors exposure on pregnant women and children's health was conducted. Two hundred and twenty-six cases and 452 controls were included. Maternal urine samples were collected before GDM diagnosis, and the urinary Se levels were determined. We assessed the association of urinary Se with GDM by conditional logistic regression with maternal urinary Se level as a categorical variable, and estimated the association between Se and glucose levels by multiple linear regression. The potential modifier roles of maternal age and fetal sex have also been assessed. Results: Lower urinary level of Se was significantly associated with a higher risk of GDM (OR = 2.35 for the tertile 1, 95% CI:1.36-4.06; adjusted OR = 1.79 for the tertile 2, 95%CI:1.09-2.95; p for trend = 0.01). Fetal sex had an interaction with Se in the association with GDM. The association was more pronounced among pregnant women with female fetuses than with male fetuses. Discussion: Our study suggested a significant negative association between urinary Se and the risk of GDM, and this association may vary depending on the fetal sex.

Community Efficacy for Non-Communicable Disease Management and Medication Adherence: The Sequential Mediating Role of Self-Efficacy and Depressive Symptoms.

Purpose: We assess whether the sequential mediating effects of self-efficacy and depressive symptoms on the relationship between community efficacy for non-communicable disease management (COEN) and medication adherence and whether these relationships differed by sex and age. Patients and Methods: Overall, 662 individuals from 12 communities in China were interviewed twice 1 year apart. Serial mediation analysis examined whether the relationship between COEN and medication adherence was mediated by self-efficacy and depressive symptoms. Model invariance across sex and age groups was assessed using multi-group analysis. Results: Serial mediation analysis indicated that self-efficacy and depressive symptoms sequentially mediated relationship between COEN and medication adherence. Multi-group analysis by sex showed that the path from self-efficacy to medication adherence was significant only for females and from depressive symptoms to medication adherence was significant only for males. Conclusion: Interventions that enhance individual self-efficacy may be beneficial in decreasing depressive symptoms and improving medication adherence.

The dynamic change of urinary selenium concentration during pregnancy and influencing factors: A longitudinal study.

BACKGROUND: Selenium concentration of one spot urine sample cannot reflect selenium status during whole pregnancy. Studies on variations of urinary selenium concentration at different stages of pregnancy are limited. AIM: To assess variations of urinary selenium concentrations during three trimesters of pregnancy and to explore the influencing factors. METHODS: This study included 2613 pregnant women from a birth cohort study (Wuhan, China) enrolled between October 2014 and October 2016. Selenium concentrations of urine samples collected at three trimesters were measured. We used a generalized linear mixed effects model to observe the changes in urinary selenium concentration during pregnancy and its influencing factors. RESULTS: The median value (range) of gestational weeks at urine sample collection was 11 (9-14), 24 (15-27), and 34 (28-41) respectively. Urine selenium concentration varied across trimesters (geometric mean: 16.34, 17.65 and 18.83 µg/g creatinine, respectively), with an upward trend (ß = -0.145, 95%CI: -0.164, -0.126) (ß = -0.066, 95%CI: -0.083, -0.048). The concentrations of urinary selenium increased with the increasing of educational level [ß (95%CI): ≤ 9 years = -0.105 (-0.163, -0.047); 10-12 years = -0.086(-0.126, -0.047); > 12 years = reference]. Pregnant women who rarely or only took multivitamins in the first trimester [ß (95% CI): rarely = -0.076 (-0.144, -0.007); only in the first three months of pregnancy = -0.104 (-0.170, -0.038); always = reference], or were not exposed to passive smoking during pregnancy（ߠ= -0.093, 95% CI: - 0.173, - 0.014), or exercised three to four days per week for the first three months before delivery（ߠ= -0.074, 95% CI: - 0.140, - 0.008) had lower urinary selenium concentrations. Pregnant women who took calcium supplements after the third month of pregnancy had higher urinary selenium levels（ߠ= 0.114, 95% CI: 0.059, 0.169). CONCLUSIONS: Urine selenium concentrations of pregnant women showed an upward trend across trimesters. Educational level, calcium or multivitamin supplementation, passive smoking, and physical exercise might impact urine selenium levels.

Plasma levels of trace element status in early pregnancy and the risk of gestational diabetes mellitus: A nested case-control study.

PURPOSE: We investigated the impacts of plasma levels of magnesium (Mg), zinc (Zn), calcium (Ca), iron (Fe), copper (Cu), selenium (Se), and chromium (Cr) on GDM risk and the potential mediation effect of blood glucose levels on the relationship between trace elements and GDM risk. METHODS: This nested case-control study was based on data from a birth cohort study conducted in Wuhan, China in 2013-2016. A total of 305 GDM cases and 305 individually-matched controls were included in the study. Conditional logistic regression models were used to estimate the associations between plasma trace element concentrations and GDM risk. A mediation analysis was conducted to explore whether blood glucose levels act as a mediator between trace element levels and GDM risk. RESULTS: An IQR increment in plasma levels of Fe and Cu was associated with a significant increase in GDM risk [OR = 2.04 (95 % CI 1.62, 2.57) and OR = 1.52 (95 % CI 1.25, 1.82)], respectively. On the other hand, an IQR increment in plasma levels of Zn and Ca was associated with a significant decrease in GDM risk [OR = 0.55 (95 % CI 0.43, 0.71) and OR = 0.72 (95 % CI 0.56, 0.92)], respectively. The mediation analysis showed significant mediation of the association between Cu and GDM risk via the FBG (%mediated: 19.27 %), 1 h-PBG (12.64 %), 2h-PBG (28.44 %) pathways. CONCLUSIONS: Plasma levels of Zn and Ca were negatively associated with GDM risk, while Fe and Cu were positively associated. Blood glucose levels act as a mediator between plasma trace element exposures and GDM risk.